1

     AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON JUNE 29, 2001.
                                                      REGISTRATION NO. 333-59094


================================================================================
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
--------------------------------------------------------------------------------


                               AMENDMENT NO. 1 TO
                                    FORM S-4
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933


                                   ---------

                        PIONEER NATURAL RESOURCES COMPANY
             (Exact Name of Registrant as Specified in its Charter)


                                                                     
        DELAWARE                                  1311                         75-2702753
(State or Other Jurisdiction of       (Primary standard industrial          (I.R.S. Employer
Incorporation or Organization)         classification code number)         Identification No.)


                            1400 WILLIAMS SQUARE WEST
                            5205 NORTH O'CONNOR BLVD.
                               IRVING, TEXAS 77039
                                 (972) 444-9001
               (Address, including zip code, and telephone number,
        including area code, of registrant's principal executive offices)

                                   ---------

                               SCOTT D. SHEFFIELD
                        PIONEER NATURAL RESOURCES COMPANY
                            1400 WILLIAMS SQUARE WEST
                            5205 NORTH O'CONNOR BLVD.
                               IRVING, TEXAS 77039
                                 (972) 444-9001
                (Name, address, including zip code, and telephone
               number, including area code, of agent for service)

                                   ---------

                                   COPIES TO:

     ROBERT L. KIMBALL                                  BRIAN M. LIDJI
  VINSON & Elkins L.L.P.                            Sayles, Lidji & Werbner
 3700 Trammell Crow Center                        A Professional Corporation
     2001 Ross Avenue                               4400 Renaissance Tower
    Dallas, Texas 75201                                 1201 Elm Street
      (214) 220-7700                                  Dallas, Texas 75270
                                                        (214) 939-8700

     Approximate date of commencement of proposed sale to the public: As soon as
practicable after the effective date of this registration statement which
relates to the merger of limited partnerships with and into Pioneer Natural
Resources USA, Inc. pursuant to the merger agreement described in the enclosed
proxy statement/prospectus.

                                   ---------

     If the securities being registered on this form are being offered in
connection with the formation of a holding company and there is compliance with
General Instruction G, check the following box. [ ]

     If this form is filed to register additional securities for an offering
pursuant to Rule 462(b) under the Securities Act, check the following box and
list the Securities Act registration statement number of the earlier effective
registration statement for the same offering. [ ]

     If this form is a post-effective amendment filed pursuant to Rule 462(d)
under the Securities Act, check the following box and list the Securities Act
registration statement number of the earlier effective registration statement
for the same offering. [ ]

                         CALCULATION OF REGISTRATION FEE



============================================================================================================
                                                   PROPOSED MAXIMUM       PROPOSED MAXIMUM        AMOUNT OF
   TITLE OF EACH CLASS OF        AMOUNT TO BE         OFFERING               AGGREGATE          REGISTRATION
SECURITIES TO BE REGISTERED     REGISTERED(1)      PRICE PER SHARE(2)     OFFERING PRICE(2)        FEE (2)
------------------------------------------------------------------------------------------------------------
                                                                                     
Common Stock, $0.01 par value     6,587,764               $8.55               $56,300,000          $14,075
============================================================================================================



     (1) Based upon the registrant's estimate of the maximum number of shares
that might be issued in connection with the proposed merger transaction.


     (2) Estimated solely for the purpose of calculating the registration fee
pursuant to Rule 457(f), based on the book value of the unaffiliated partnership
interests to be cancelled in the transaction, computed as of the latest
practicable date. A filing fee of $20,500 was paid pursuant to the filing on
April 17, 2001 by the registrant and Pioneer Natural Resources USA, Inc. of a
preliminary Schedule 13e-3. Pursuant to Rule 240.0-11(a)(2) of the Securities
Exchange Act of 1934, this amount has been credited against the amount that
would otherwise be payable in connection with this filing, resulting in no
additional payment herewith.


     THE REGISTRANT HEREBY AMENDS THIS REGISTRATION STATEMENT ON SUCH DATE OR
DATES AS MAY BE NECESSARY TO DELAY ITS EFFECTIVE DATE UNTIL THE REGISTRANT SHALL
FILE A FURTHER AMENDMENT WHICH SPECIFICALLY STATES THAT THIS REGISTRATION
STATEMENT SHALL THEREAFTER BECOME EFFECTIVE IN ACCORDANCE WITH SECTION 8(a) OF
THE SECURITIES ACT OF 1933 OR UNTIL THE REGISTRATION STATEMENT SHALL BECOME
EFFECTIVE ON SUCH DATE AS THE SECURITIES AND EXCHANGE COMMISSION, ACTING
PURSUANT TO SAID SECTION 8(a), MAY DETERMINE.

================================================================================

   2


                       PIONEER NATURAL RESOURCES USA, INC.
                            1400 Williams Square West
                            5205 North O'Connor Blvd.
                               Irving, Texas 75039

                 NOTICE OF SPECIAL MEETINGS OF LIMITED PARTNERS
                          TO BE HELD ON       , 2001

To the Limited Partners of 46
Parker & Parsley Limited Partnerships:

     This is a notice that a special meeting of the limited partners of each of
the following 46 limited partnerships will be held on             , 2001, at
10:00 a.m., at the Dallas Marriott Las Colinas Hotel, Irving, Texas 75039:


                                                      
Parker & Parsley 81-I, Ltd.                              Parker & Parsley 88-A Conv., L.P.
Parker & Parsley 81-II, Ltd.                             Parker & Parsley 88-A, L.P.
Parker & Parsley 82-I, Ltd.                              Parker & Parsley 88-B Conv., L.P.
Parker & Parsley 82-II, Ltd.                             Parker & Parsley 88-B, L.P.
Parker & Parsley 82-III, Ltd.                            Parker & Parsley 88-C Conv., L.P.
Parker & Parsley 83-A, Ltd.                              Parker & Parsley 88-C, L.P.
Parker & Parsley 83-B, Ltd.                              Parker & Parsley Producing Properties 88-A, L.P.
Parker & Parsley 84-A, Ltd.                              Parker & Parsley Private Investment 88, L.P.
Parker & Parsley 85-A, Ltd.                              Parker & Parsley 89-A Conv., L.P.
Parker & Parsley 85-B, Ltd.                              Parker & Parsley 89-A, L.P.
Parker & Parsley Private Investment 85-A, Ltd.           Parker & Parsley 89-B Conv., L.P.
Parker & Parsley Selected 85 Private Investment, Ltd.    Parker & Parsley 89-B, L.P.
Parker & Parsley 86-A, Ltd.                              Parker & Parsley Private Investment 89, L.P.
Parker & Parsley 86-B, Ltd.                              Parker & Parsley 90-A Conv., L.P.
Parker & Parsley 86-C, Ltd.                              Parker & Parsley 90-A, L.P.
Parker & Parsley Private Investment 86, Ltd.             Parker & Parsley 90-B Conv., L.P.
Parker & Parsley 87-A Conv., Ltd.                        Parker & Parsley 90-B, L.P.
Parker & Parsley 87-A , Ltd.                             Parker & Parsley 90-C Conv., L.P.
Parker & Parsley 87-B Conv., Ltd.                        Parker & Parsley 90-C, L.P.
Parker & Parsley 87-B, Ltd.                              Parker & Parsley Private Investment 90, L.P.
Parker & Parsley Producing Properties 87-A, Ltd.         Parker & Parsley 90 Spraberry Private Development, L.P.
Parker & Parsley Producing Properties 87-B, Ltd.         Parker & Parsley 91-A, L.P.
Parker & Parsley Private Investment 87, Ltd.             Parker & Parsley 91-B, L.P.



     Parker & Parsley Petroleum USA, Inc. and other predecessors of Pioneer
Natural Resources USA, Inc., a Delaware corporation that we call Pioneer USA,
sponsored each of the partnerships. Pioneer USA is the managing or sole general
partner of each of the partnerships. Pioneer USA is a direct 100% owned
subsidiary of Pioneer Natural Resources Company, a Delaware corporation that we
call Pioneer Parent.


     The purpose of the special meeting for each partnership in which you own an
interest is for you to consider and vote on the following matters:


     1. A proposal to approve an Agreement and Plan of Merger dated as of ,
2001, among Pioneer Parent, Pioneer USA and each of the partnerships. Each
partnership that approves this proposal, which we call a participating
partnership, will merge with and into Pioneer USA, with Pioneer USA surviving
the merger. Each partnership interest of a participating partnership, other than
Pioneer USA's partnership interests, will be converted into shares of common
stock, par value $.01 per share, of Pioneer Parent. The number of shares of
common stock Pioneer Parent will offer for all partnership interests of a
participating partnership will be based on (1) the participating partnership's
merger value and (2) the average closing price of the Pioneer Parent common
stock, as reported by the New York Stock Exchange, for the ten trading days
ending three business days before the initial date of the special meeting for
the partnership. The merger value for a participating partnership is equal to
the sum of the present value of estimated future net revenues from the
partnership's estimated oil and gas reserves and its net working capital, in
each case as of March 31, 2001, less its pro rata share, based on its reserve
value, of the estimated expenses and fees of the mergers of all of the
partnerships and less the cash distribution to be mailed on or about July 12,
2001, by the partnership to its partners. For purposes of illustration in this
document, we have calculated the number of shares to be issued based on an
assumed average closing price of $18.00 per share of Pioneer Parent common
stock. Prior to the date of the special meeting for each partnership, we will
update the number of shares to be issued using the actual average closing price
of Pioneer Parent common stock for the ten trading days ending three business
days before the initial date of the special meeting. The Pioneer Parent common
stock will be allocated among the partners based on the liquidation provisions
of each partnership agreement. Pioneer Parent will not issue fractional shares
to any limited partner upon completion of the merger of any partnership.
Instead, Pioneer Parent will round any fractional shares of Pioneer Parent
common stock up to the nearest whole share. Pioneer USA will not receive any
Pioneer Parent common stock for its partnership interests in the participating
partnerships.



                                      -1-
   3


     2. A proposal to amend the partnership agreement of each partnership to
permit the partnership's merger with Pioneer USA. If the amendment is not
approved, that partnership cannot merge into Pioneer USA even if the partners of
that partnership approve the merger agreement.

     3.  A proposal (A) to approve the opinion issued to Pioneer USA by
on behalf of the limited partners of each partnership that neither the grant nor
the exercise of the right to approve the merger of the partnership by its
limited partners (1) will result in the loss of any limited partner's limited
liability or (2) will adversely affect the federal income tax classification of
the partnership or any of its limited partners and (B) to approve the selection
of as special legal counsel for the limited partners of each partnership to
render the legal opinion.


     4. Other business that properly comes before the special meeting or any
adjournments or postponements of the special meeting. Pioneer USA is not aware
of any other business for the special meeting.



     The accompanying proxy statement/prospectus contains information about each
merger, including the amount of Pioneer Parent common stock that will be offered
to limited partners per $1,000 initial investment in each partnership, and
descriptions of the merger agreement, the merger amendment and the legal opinion
of the special legal counsel for the limited partners. The proxy
statement/prospectus also contains a copy of the merger agreement, the merger
amendment and the legal opinion.


     Pioneer USA set the close of business on              , 2001, as the record
date to identify the limited partners who are entitled to notice of and to vote
at each special meeting or any adjournments or postponements of the special
meeting. During the ten business days before the special meeting, you may
examine lists of the limited partners of each partnership in which you own an
interest at the offices of Pioneer USA during normal business hours for any
purpose relevant to the special meeting for each partnership in which you own an
interest.


     ON             , 2001, PIONEER USA'S BOARD OF DIRECTORS UNANIMOUSLY
DETERMINED THAT THE MERGER OF EACH PARTNERSHIP IN WHICH YOU OWN AN INTEREST IS
ADVISABLE, FAIR TO YOU AS AN UNAFFILIATED LIMITED PARTNER, AND IN YOUR BEST
INTERESTS. THE BOARD RECOMMENDS THAT YOU, AS AN UNAFFILIATED LIMITED PARTNER,
VOTE FOR THE MERGER AGREEMENT, THE MERGER AMENDMENT, THE SELECTION OF SPECIAL
LEGAL COUNSEL FOR THE LIMITED PARTNERS AND THAT COUNSEL'S LEGAL OPINION FOR EACH
PARTNERSHIP IN WHICH YOU OWN AN INTEREST. ALTHOUGH PIONEER USA'S BOARD OF
DIRECTORS HAS ATTEMPTED TO FULFILL ITS FIDUCIARY DUTIES TO YOU, PIONEER USA'S
BOARD OF DIRECTORS HAD CONFLICTING INTERESTS IN EVALUATING EACH MERGER BECAUSE
EACH MEMBER OF ITS BOARD OF DIRECTORS IS ALSO AN OFFICER OF PIONEER PARENT. Each
partnership requires a favorable vote of the holders of a majority of its
limited partnership interests to approve the merger agreement, the merger
amendment, the selection of special legal counsel for the limited partners and
that counsel's legal opinion, except that Parker & Parsley 91-A, L.P. and Parker
& Parsley 91-B, L.P. each require the favorable vote of the holders, other than
Pioneer USA, of 6-2/3% of its limited partnership interests to approve those
merger proposals.


     IF YOU DO NOT SEND IN YOUR PROXY CARD OR VOTE AT THE SPECIAL MEETING FOR A
PARTNERSHIP IN WHICH YOU OWN AN INTEREST, IT WILL HAVE THE SAME EFFECT AS IF YOU
VOTED AGAINST THE MERGER OF THAT PARTNERSHIP.

     You are requested to sign, vote and date the enclosed proxy card and return
it promptly in the enclosed envelope, even if you expect to be present at each
special meeting for the partnerships in which you own an interest. If you give a
proxy, you can revoke it at any time before the special meeting for the
partnership as to which you are revoking your proxy. If you are present at the
special meeting for a partnership in which you own an interest, you may withdraw
your proxy and vote in person.

                                            By Order of the Board of Directors,

                        , 2001
                                            Mark L. Withrow
                                            Director, Executive Vice President,
                                            General Counsel and Secretary



                                      -2-
   4


The information in this prospectus is not complete and may be changed. We may
not sell these securities until the registration statement filed with the
Securities and Exchange Commission is effective. This prospectus is not an offer
to sell these securities and it is not soliciting an offer to buy these
securities in any state where the offer or sale is not permitted.


PRELIMINARY PROXY STATEMENT/PROSPECTUS, SUBJECT TO COMPLETION, DATED
JUNE    , 2001                                                            [LOGO]

                        PIONEER NATURAL RESOURCES COMPANY
                       PIONEER NATURAL RESOURCES USA, INC.
                            1400 WILLIAMS SQUARE WEST
                            5205 NORTH O'CONNOR BLVD.
                               IRVING, TEXAS 75039

                                                                          , 2001
Dear Limited Partners:



     Pioneer Natural Resources Company, a Delaware corporation that we call
Pioneer Parent, and we at Pioneer Natural Resources USA, Inc., a Delaware
corporation and 100% owned subsidiary of Pioneer Parent that we call Pioneer
USA, desire to acquire 46 limited partnerships. We are the managing or sole
general partner of each of the partnerships.



     If you and the other limited partners of a partnership approve the merger
of the partnership, the partnership will be merged with and into Pioneer USA,
with Pioneer USA surviving the merger. We call each partnership that merges into
Pioneer USA a participating partnership. Each partnership interest of a
participating partnership will be converted into shares of common stock, par
value $.01 per share, of Pioneer Parent. The number of shares of common stock
Pioneer Parent will offer for all partnership interests of a participating
partnership will be based on (1) the participating partnership's merger value
and (2) the average closing price of the Pioneer Parent common stock, as
reported by the New York Stock Exchange, for the ten trading days ending three
business days before the initial date of the special meeting for the
partnership. The merger value for a participating partnership is equal to the
sum of the present value of estimated future net revenues from the partnership's
estimated oil and gas reserves and its net working capital, in each case as of
March 31, 2001, less its pro rata share, based on its reserve value, of the
estimated expenses and fees of the mergers of all of the partnerships and less
the cash distribution to be mailed on or about July 12, 2001, by the partnership
to its partners.



     The merger value for each partnership is based on the reserve value of the
partnership's underlying properties, which reserve value has not been reduced
for general and administrative expenses. As a result, we believe the merger
value is essentially the same value or a higher value than the liquidation value
that might have been achieved by selling the partnership's property interests on
March 31, 2001, and liquidating the partnership at that time.



     We have retained Robert A. Stanger & Co., Inc., which we call Stanger, to
issue an opinion regarding the fairness of the merger value to the limited
partners in connection with the merger of each partnership. The written opinion
of Stanger is contained in this document. You should read all of it carefully.



     We can complete the merger of each partnership only if the holders of its
limited partnership interests approve the merger agreement, the amendment to the
partnership agreement to permit the merger, the selection of special legal
counsel for the limited partners and that counsel's legal opinion. This document
provides information about each proposed merger. This document also constitutes
a prospectus by Pioneer Parent for up to an aggregate of 5,855,813 shares of
Pioneer Parent common stock to be issued in the proposed merger transaction,
based on an assumed average closing price of $18.00 per share of Pioneer Parent
common stock. Please give all of this information your careful attention.


     YOUR VOTE IS IMPORTANT. Whether or not you plan to attend the special
meeting for each partnership in which you own an interest, please take the time
to vote by completing and mailing to us the enclosed proxy card. This will not
prevent you from revoking your proxy at any time prior to the special meeting
for each partnership in which you own an interest or from voting your
partnership interests in person if you later choose to attend the special
meeting for each partnership in which you own an interest.


     We intend to mail certificates representing shares of Pioneer Parent common
stock to the partners of each partnership that approves the merger transaction
promptly after completing the merger of the partnership. Certificates
representing partnership interests will be automatically cancelled, and you will
not have to surrender your certificates to receive the Pioneer Parent common
stock.



     YOUR CERTIFICATE THAT YOU ARE NOT A FOREIGN PERSON, WHICH WE CALL A
CERTIFICATION OF NON-FOREIGN STATUS, IS IMPORTANT. Whether or not you plan to
vote on the merger of each partnership in which you own an interest, please take
the time to complete and return to us the enclosed certification of non-foreign
status. If we receive a properly completed certification of non-foreign status
from you, we will not withhold federal income taxes on the Pioneer Parent common
stock to be issued to you upon the merger of each partnership in which you own
an interest.


                                             Sincerely,


                                             Mark L. Withrow
                                             Director, Executive Vice President,
                                             General Counsel and Secretary

     YOU SHOULD CAREFULLY CONSIDER THE RISKS RELATING TO THE MERGER OF EACH
PARTNERSHIP IN WHICH YOU OWN AN INTEREST DESCRIBED IN "RISK FACTORS" BEGINNING
ON PAGE 17. THESE INCLUDE:


     o    THE MERGER VALUE FOR THE PARTNERSHIP DETERMINES THE AMOUNT OF PIONEER
          PARENT COMMON STOCK YOU WILL RECEIVE IN THE MERGER OF THE PARTNERSHIP.
          PIONEER PARENT AND PIONEER USA DETERMINED EACH MERGER VALUE AND WILL
          NOT ADJUST IT FOR CHANGES IN PARTNERSHIP VALUE BEFORE THE MERGER IS
          COMPLETED.


     o    YOU WERE NOT INDEPENDENTLY REPRESENTED IN ESTABLISHING THE TERMS OF
          ANY MERGER.


     o    OUR BOARD OF DIRECTORS HAD CONFLICTING INTERESTS IN EVALUATING EACH
          MERGER BECAUSE EACH MEMBER OF OUR BOARD OF DIRECTORS IS ALSO AN
          OFFICER OF PIONEER PARENT.



     NEITHER THE SECURITIES AND EXCHANGE COMMISSION NOR ANY STATE SECURITIES
REGULATORS HAVE APPROVED ANY OF THE MERGERS, THE PIONEER PARENT COMMON STOCK TO
BE ISSUED IN EACH MERGER OR THE FAIRNESS OR THE MERITS OF EACH MERGER OR HAVE
DETERMINED WHETHER THE INFORMATION CONTAINED IN THIS DOCUMENT IS ACCURATE OR
ADEQUATE. ANY REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE.


     This proxy statement/prospectus is dated              , 2001. It is first
being mailed to the limited partners on or about        , 2001.


   5




                        PIONEER NATURAL RESOURCES COMPANY



     The world map below reflects the geographic locations of Pioneer Parent's
exploration, development and production operations.


                                     [MAP]


                       WHERE YOU CAN FIND MORE INFORMATION



     Pioneer Parent and each of the 25 partnerships listed below that we call a
reporting partnership file annual, quarterly and special reports, proxy
statements and other information with the Securities and Exchange Commission:




                                                     
Parker & Parsley 82-I, Ltd.                             Parker & Parsley Producing Properties 87-B, Ltd.
Parker & Parsley 82-II, Ltd.                            Parker & Parsley 88-A, L.P.
Parker & Parsley 83-A, Ltd.                             Parker & Parsley 88-B, L.P.
Parker & Parsley 83-B, Ltd.                             Parker & Parsley Producing Properties 88-A, L.P.
Parker & Parsley 84-A, Ltd.                             Parker & Parsley 89-A, L.P.
Parker & Parsley 85-A, Ltd.                             Parker & Parsley 90-A L.P.
Parker & Parsley 85-B, Ltd.                             Parker & Parsley 90-B Conv., L.P.
Parker & Parsley 86-A, Ltd.                             Parker & Parsley 90-B, L.P.
Parker & Parsley 86-B, Ltd.                             Parker & Parsley 90-C Conv., L.P.
Parker & Parsley 86-C, Ltd.                             Parker & Parsley 90-C, L.P.
Parker & Parsley 87-A, Ltd.                             Parker & Parsley 91-A, L.P.
Parker & Parsley 87-B, Ltd.                             Parker & Parsley 91-B, L.P.
Parker & Parsley Producing Properties 87-A, Ltd.





You may read and copy any reports, statements or other information that Pioneer
Parent or any reporting partnership files at the SEC's public reference room at
450 Fifth Street, N.W., Washington, D.C. 20549, or at the SEC's public reference
rooms at 7 World Trade Center, Suite 1300 New York, New York 10048 and at 500
West Madison Street, Suite 1400, Chicago, Illinois 60661. Copies of these
materials may also be obtained from the SEC at prescribed rates by writing to
the Public Reference Section of the Securities and Exchange Commission, 450
Fifth Street, N.W., Washington, D.C. 20549. Please call the SEC at
1-800-SEC-0330 for further information on the public reference rooms. Pioneer
Parent's and each reporting partnership's filings with the SEC are also
available to the public from commercial document retrieval services and at the
web site maintained by the SEC at http://www.sec.gov.



     Pioneer Parent's common stock is listed on the New York Stock Exchange and
the Toronto Stock Exchange, under the symbol "PXD." Pioneer Parent's reports and
other information filed with the SEC can also be inspected at the offices of the
New York Stock Exchange and the Toronto Stock Exchange.



   6


     Pioneer Parent filed a registration statement on Form S-4 to register with
the SEC Pioneer Parent common stock to be issued to the limited partners of each
participating partnership. This document is a part of that registration
statement and constitutes the prospectus of Pioneer Parent in addition to being
the proxy statement of each partnership. As allowed by SEC rules, this document
does not contain all the information you can find in the registration statement
or the exhibits to the registration statement.



     The SEC allows Pioneer Parent to incorporate by reference information into
this document, which means that Pioneer Parent can disclose important
information to you by referring you to another document filed separately with
the SEC. The information incorporated by reference is deemed to be part of this
document, except for any information superseded by information in this document.
This document incorporates by reference the documents set forth below that
Pioneer Parent has previously filed with the SEC and that contain important
information about Pioneer Parent and its finances:



     o    Quarterly Report on Form 10-Q for the three months ended March 31,
          2001



     o    Annual Report on Form 10-K for the year ended December 31, 2000



     o    The description of Pioneer Parent common stock contained in Pioneer
          Parent's registration statement on Form 8-A filed on August 5, 1997,
          as amended by Form 8-A/A filed on August 8, 1997.



     Pioneer Parent is also incorporating by reference additional documents that
it files with the SEC under sections 13(a), 13(c), 14 or 15(d) of the Securities
Exchange Act of 1934 between the date of this document and the date of the
special meeting for each partnership.



     The supplement to this document for each partnership contains financial
information for the partnership. The information supplement for each partnership
constitutes an integral part of this document. Please carefully read the
supplement for each partnership in which you are a limited partner.



     Pioneer Parent has supplied all information contained or incorporated by
reference in this document relating to Pioneer Parent, and each partnership has
supplied all the information contained in this document relating to the
partnership.



     You can obtain any of the documents incorporated by reference through
Pioneer Parent or the SEC. Documents incorporated by reference are available
from Pioneer Parent without charge. Exhibits to the documents will not be sent,
however, unless those exhibits have specifically been incorporated by reference
as exhibits in this document. Limited partners of each partnership may obtain
documents incorporated by reference in this document by requesting them in
writing or by telephone at the following address:



                      Pioneer Natural Resources Company
                      1400 Williams Square West
                      5205 North O'Connor Blvd.
                      Irving, Texas 77039
                      Telephone: (972) 444-9001
                      Attention: Investor Relations



     IF YOU WOULD LIKE TO REQUEST DOCUMENTS FROM PIONEER PARENT OR ANY
PARTNERSHIP IN WHICH YOU OWN AN INTEREST, PLEASE DO SO BY          , 2001
[INSERT 5TH BUSINESS DAY BEFORE MEETING] TO RECEIVE THEM BEFORE THE SPECIAL
MEETING FOR THE PARTNERSHIP.



     You should rely only on the information contained or incorporated by
reference in this document to vote on the merger of each partnership in which
you own an interest. We have not authorized anyone to give any information that
is different from what is contained in this document. This document is dated
        , 2001. You should not assume that the information contained in this
document is accurate as of any date other than that date, and neither the
mailing of this document to you nor the issuance of Pioneer Parent common stock
in the merger of each partnership shall create an implication to the contrary.



   7


                                TABLE OF CONTENTS




                                                                            Page
                                                                            ----
                                                                         
QUESTIONS AND ANSWERS ABOUT THE
   MERGER OF EACH PARTNERSHIP ............................................   iv
SUMMARY ..................................................................    1
RISK FACTORS  ............................................................   18
   Risk Factors Relating to the Merger of Each
   Partnership ...........................................................   18
     The Merger Value for Each Partnership
       Involves Estimates that May Vary
       Materially from the Quantities of Oil and
       Gas Actually Recovered, and
       Consequently Future Net Revenues ..................................   18
     The Merger Value for a Partnership Will Not
       Be Adjusted For Changes in Oil and Gas
       Prices Before the Completion of Its
       Merger ............................................................   18
     The Number of Shares of Pioneer Parent
       Common Stock the Limited Partners of
       Each Partnership Will Receive May
       Decrease Between Now and the
       Completion of the Merger of the
       Partnership .......................................................   18
     Current Market Prices for Oil and Gas
       May Be Higher than the Merger Value
       for a Partnership, Which May Affect
       Deliverability of the Fairness Opinion ............................   18
     You Were Not Independently Represented
       in Establishing the Terms of the Merger
       of Each Partnership ...............................................   18
     The Interests of Pioneer Parent, Pioneer
       USA and Their Directors and Officers
       May Differ From Your Interests ....................................   19
     It Is Unclear What the Market Demand Is
       For Any Partnership or its Assets or
       That the Terms of the Merger of Each
       Partnership Are As Favorable As Could
       Be Obtained in a Third Party Sale .................................   19
     Potential Litigation Challenging the Merger
       of a Partnership May Delay or Block the
       Merger and, As a Result, Your Receipt
       of the Pioneer Parent Common Stock ................................   19
     Repurchase Offers in 2001 by Each of the
       Six Partnerships with a Repurchase
       Obligation were Higher than the Merger
       Value for the Partnership .........................................   19
     You Could be Bound by the Merger of Each
       Partnership in Which You Own an Interest
       Even If You Do Not Vote in Favor of
       the Merger ........................................................   20
   Risks Associated With an Investment in
   Pioneer Parent ........................................................   20
     Limited Partners Who Become Pioneer
       Parent Stockholders Will Own Stock in
       a Corporation Rather than a Limited
       Partnership Interest in a Limited
       Partnership Resulting In a
       Fundamental Change in the
       Nature of Their Investments .......................................   20
     Pioneer Parent Might Not Declare
       Dividends .........................................................   20
     Limited Partners Who Become Pioneer
       Parent Stockholders May Be Diluted ................................   20
     Dividends Paid to Pioneer Parent
       Stockholders Are Taxed at Two Levels ..............................   21
     Pioneer Parent is an Independent Oil
       and Gas Exploration and Development
       Company and Its Business Activities
       Involve Risks .....................................................   21
SPECIAL FACTORS ..........................................................   24
   Background of the Merger of Each Partnership...........................   24
   Reasons for the Merger of Each Partnership ............................   30
   Recommendation of Pioneer USA .........................................   32
   Fairness Opinion ......................................................   33
   Summary Reserve Report ................................................   40
   Alternative Transactions to the Merger of
     Each Partnership ....................................................   41
FORWARD-LOOKING STATEMENTS ...............................................   43
METHOD OF DETERMINING MERGER
   VALUE FOR EACH PARTNERSHIP AND
   AMOUNT OF PIONEER PARENT
   COMMON STOCK OFFERED ..................................................   44
   Components of Merger Value for Each
     Partnership .........................................................   44
   Allocation of Merger Value for Each
     Partnership Among Partners of the
     Partnership .........................................................   45
   Other Methods of Determining Merger
     Values ..............................................................   46
THE MERGER OF EACH PARTNERSHIP ...........................................   47
   General ...............................................................   47
   Legal Opinion for Limited Partners ....................................   47
   Distribution of Pioneer Parent Common Stock ...........................   48
   Fractional Shares .....................................................   48
   Material U.S. Federal Income Tax
     Consequences ........................................................   48
   Accounting Treatment ..................................................   50
   Effect of Debt Owed by a Limited Partner
     to Pioneer USA on Amount of Pioneer
     Parent Common Stock to be Received
     by the Limited Partner ..............................................   50
   Effect of Merger of Each Partnership on
     Limited Partners Who Do Not Vote in
     Favor of the Merger; No Appraisal or
     Dissenters' Rights ..................................................   51
   Future of Nonparticipating Partnerships ...............................   51
   Nonmanaging General Partners of Some
     Partnerships ........................................................   51
   Third Party Offers ....................................................   52
   Merger Amendment ......................................................   52
   Termination of Registration and Reporting
     Requirements ........................................................   52
   Elimination of a Fairness Opinion
     Requirement That Would Otherwise
     Benefit Pioneer USA .................................................   53
   Payment of Expenses and Fees ..........................................   53
THE MERGER AGREEMENT .....................................................   54
   Structure; Effective Time .............................................   54
   Effect of the Merger of Each Partnership ..............................   54
   Conduct of Business Prior to the Merger
     of Each Partnership .................................................   54
   Other Agreements ......................................................   54




                                      -i-
   8





                                                                            Page
                                                                            ----
                                                                         
   Representations and Warranties of
     Pioneer Parent, Pioneer USA and Each
     Partnership .........................................................   55
   Conditions to the Merger of Each Partnership...........................   55
   Termination of the Merger Agreement and
     the Merger of Any Partnership .......................................   56
   Amendments; Waivers ...................................................   57
THE SPECIAL MEETINGS .....................................................   58
   Time and Place; Purpose ...............................................   58
   Record Date; Voting Rights and Proxies ................................   58
   Revocation of Proxies .................................................   59
   Solicitation of Proxies ...............................................   60
   Quorum ................................................................   60
   Required Vote; Broker Non-Votes .......................................   60
   Participation by Assignees ............................................   61
   Special Requirements for Some Limited
     Partners ............................................................   61
   Validity of Proxy Cards ...............................................   61
   Local Laws ............................................................   61
COMPARATIVE PER SHARE MARKET
   PRICE AND DIVIDEND INFORMATION ........................................   62
INTERESTS OF PIONEER PARENT,
   PIONEER USA AND THEIR DIRECTORS
   AND OFFICERS ..........................................................   63
   Conflicting Duties of Pioneer USA, Individually
     and as General Partner ..............................................   63
   Pioneer USA's Employees Provide Services
     to the Partnerships .................................................   63
   Financial Interests of Directors and Officers..........................   63
   The Partnerships Pay Operator Fees to
     Pioneer USA .........................................................   63
OWNERSHIP OF PARTNERSHIP
   INTERESTS .............................................................   64
TRANSACTIONS AMONG ANY
   PARTNERSHIP, PIONEER PARENT,
   PIONEER USA AND THEIR DIRECTORS
   AND OFFICERS ..........................................................   64
MANAGEMENT ...............................................................   66
   Pioneer Parent ........................................................   66
   Pioneer USA ...........................................................   67
PIONEER PARENT ...........................................................   69
   Key Projects to Increase Production ...................................   69
   More Information ......................................................   70
THE PARTNERSHIPS .........................................................   71
   General ...............................................................   71
   The Drilling Partnerships .............................................   71
   The Income Partnerships ...............................................   72
COMPARISON OF RIGHTS OF
   STOCKHOLDERS AND PARTNERS .............................................   73
   General ...............................................................   73
   Summary Comparison of Terms of Shares of
     Pioneer Parent Common Stock and Partnership
     Interests ...........................................................   73
LEGAL MATTERS ............................................................   79
INDEPENDENT AUDITORS AND
   INDEPENDENT PETROLEUM
   CONSULTANTS ...........................................................   79
COMMONLY USED OIL AND
   GAS TERMS .............................................................   81
UNAUDITED PRO FORMA COMBINED
   FINANCIAL STATEMENTS ..................................................  P-1




                               LIST OF APPENDICES




                                                                                 Appendix
                                                                                 --------
                                                                              
General Information Relating to Each Partnership...............................      A
  Table 1     Jurisdiction of Organization, Initial Subscription Price for
              Each Unit, Initial Investment by Limited Partners and Number of
              Limited Partners as of March 31, 2001
  Table 2     Merger Value Attributable to Pioneer USA, Nonmanaging General
              Partners and Limited Partners
  Table 3     Merger Value Attributable to Partnership Interests of Limited
              Partners Per $1,000 Investment
  Table 4     Ownership Percentage and Merger Value Attributable to Nonmanaging
              General Partners Other Than Pioneer USA
  Table 5     Ownership Percentage and Merger Value Attributable to Pioneer USA
              in Its Capacities as General Partner, Nonmanaging General Partner
              and Limited Partner
  Table 6     Voting Percentage and Initial Investment Owned by Pioneer USA in
              Its Capacity as a Limited Partner as of March 31, 2001
  Table 7     Historical Quarterly Partnership Distributions to the Limited
              Partners Per $1,000 Investment from Inception through July 31,
              2001
  Table 8     Annual Repurchase Prices and Aggregate Annual Repurchase Payments
  Table 9     Participation in Costs and Revenues of Each Partnership
  Table 10    Average Oil, Natural Gas Liquids and Gas Sales Prices and
              Production Costs for the Three Months Ended March 31, 2001 and
              2000 and the Years Ended December 31, 2000, 1999 and 1998
  Table 11    Proved Reserves Attributable to Pioneer USA, Nonmanaging General
              Partners and Limited Partners as of December 31, 2000
  Table 12    Partnership Estimated Reserves Attributable to Pioneer USA,
              Nonmanaging General Partners and Limited Partners as of March 31,
              2001
  Table 13    Oil, Natural Gas Liquids and Gas Production for the Three Months
              Ended March 31, 2001 and 2000 and the Years Ended December 31,
              2000, 1999 and 1998




                                      -ii-
   9





                                                                                 Appendix
                                                                                 --------
                                                                              

  Table 14    Productive Wells and Developed Acreage as of March 31, 2001
  Table 15    Recent Trades of Partnership Interests Per $1,000 Investment for
              the Three Months Ended March 31, 2001 and the Years Ended
              December 31, 2000 and 1999
  Table 16    Reserve Value Attributable to Pioneer USA, Nonmanaging General
              Partners and Limited Partners as of March 31, 2001
Summary Reserve Review of Williamson Petroleum Consultants, Inc. for the
Partnerships as of March 31, 2001 [To be provided by Amendment].................     B
Summary Reserve Report of Williamson Petroleum Consultants, Inc. for the
Partnerships as of December 31, 2000............................................     C
Form of Fairness Opinion of Robert A. Stanger & Co., Inc. ......................     D
The Merger Proposals ...........................................................     E
Form of Agreement and Plan of Merger ...........................................     F



     WE HAVE PREPARED A SEPARATE SUPPLEMENT TO THIS DOCUMENT FOR EACH
PARTNERSHIP. EACH SUPPLEMENT INCLUDES:

     o    A TABLE CONTAINING:

          -    THE AGGREGATE INITIAL INVESTMENT BY THE LIMITED PARTNERS

          -    THE AGGREGATE HISTORICAL LIMITED PARTNER DISTRIBUTIONS THROUGH
               JULY 31, 2001


          -    THE MERGER VALUE ATTRIBUTABLE TO PARTNERSHIP INTERESTS OF LIMITED
               PARTNERS, EXCLUDING PIONEER USA



          -    THE MERGER VALUE PER $1,000 LIMITED PARTNER INVESTMENT



          -    THE MERGER VALUE PER $1,000 LIMITED PARTNER INVESTMENT AS A
               MULTIPLE OF DISTRIBUTIONS FOR THE PAST FOUR QUARTERLY
               DISTRIBUTIONS INCLUDING THE DISTRIBUTION IN JULY 2001


          -    THE BOOK VALUE PER $1,000 LIMITED PARTNER INVESTMENT AS OF MARCH
               31, 2001 AND AS OF DECEMBER 31, 2000


          -    THE GOING CONCERN VALUE PER $1,000 LIMITED PARTNER INVESTMENT



          -    THE LIQUIDATION VALUE PER $1,000 LIMITED PARTNER INVESTMENT


          -    THE ORDINARY TAX LOSS PER $1,000 LIMITED PARTNER INVESTMENT IN
               YEAR OF INITIAL INVESTMENT


     o    INFORMATION ABOUT:



          -    THE LEGAL OPINION FOR THE LIMITED PARTNERS



          -    THE TERM OF THE PARTNERSHIP



     o    FOR EACH PARTNERSHIP THAT IS SUBJECT TO THE REPORTING REQUIREMENTS OF
          THE SECURITIES EXCHANGE ACT OF 1934, WHICH WE CALL A REPORTING
          PARTNERSHIP, THE PARTNERSHIP'S QUARTERLY REPORT ON FORM 10-Q,
          INCLUDING MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION
          AND RESULTS OF OPERATIONS, FOR THE THREE MONTHS ENDED MARCH 31, 2001


     o    FOR EACH REPORTING PARTNERSHIP, THE PARTNERSHIP'S ANNUAL REPORT ON
          FORM 10-K, INCLUDING MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL
          CONDITION AND RESULTS OF OPERATIONS, FOR THE YEAR ENDED DECEMBER 31,
          2000


     o    FOR EACH PARTNERSHIP THAT IS NOT SUBJECT TO THE REPORTING REQUIREMENTS
          OF THE SECURITIES EXCHANGE ACT OF 1934, WHICH WE CALL A NONREPORTING
          PARTNERSHIP, THE PARTNERSHIP'S FINANCIAL STATEMENTS, INCLUDING
          MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND
          RESULTS OF OPERATIONS, FOR THE THREE MONTHS ENDED MARCH 31, 2001


     o    FOR EACH NONREPORTING PARTNERSHIP, THE PARTNERSHIP'S FINANCIAL
          STATEMENTS, INCLUDING MANAGEMENT'S DISCUSSION AND ANALYSIS OF
          FINANCIAL CONDITION AND RESULTS OF OPERATIONS, FOR THE YEAR ENDED
          DECEMBER 31, 2000

     o    SELECTED HISTORICAL FINANCIAL DATA FOR THE PARTNERSHIP FOR THE THREE
          MONTHS ENDED MARCH 31, 2001 AND 2000 AND THE FIVE YEARS ENDED DECEMBER
          31, 2000

THE SUPPLEMENT CONSTITUTES AN INTEGRAL PART OF THIS DOCUMENT FOR EACH
PARTNERSHIP. PLEASE CAREFULLY READ ALL OF THE SUPPLEMENTS FOR THE PARTNERSHIPS
IN WHICH YOU ARE A LIMITED PARTNER.


                                      -iii-
   10


           QUESTIONS AND ANSWERS ABOUT THE MERGER OF EACH PARTNERSHIP


Q: HOW DO I VOTE?

A: After reading this document, please fill out and sign your proxy card. Then
mail your signed proxy card in the enclosed return envelope as soon as possible
so that your partnership interests will be represented at the special meeting
for each partnership in which you own an interest.

Q: WHAT HAPPENS IF I DO NOT RETURN A PROXY CARD?

A: The failure to return your proxy card will have the same effect as voting
against the merger for each partnership in which you own an interest.

Q: MAY I VOTE IN PERSON?

A: Yes. You may attend the special meeting for each partnership in which you own
an interest and vote your partnership interests in person, rather than signing
and mailing your proxy card.

Q: MAY I CHANGE MY VOTE AFTER I HAVE MAILED MY SIGNED PROXY CARD?


A: Yes. You may revoke your vote at any time before your proxy is voted at the
special meeting for each partnership in which you own an interest by following
the instructions beginning on page 59. You then may either change your vote by
sending in a new proxy card or by attending the special meeting for each
partnership in which you own an interest and voting in person.


Q: IF MY PARTNERSHIP INTERESTS ARE HELD IN A RETIREMENT ACCOUNT BY A CUSTODIAN,
WILL MY CUSTODIAN VOTE MY PARTNERSHIP INTERESTS FOR ME?

A: Your custodian will not be able to vote your partnership interests. You
should refer to the instructions included on your proxy card to vote your
partnership interests.

Q: SHOULD I SEND IN MY CERTIFICATES FOR MY PARTNERSHIP INTERESTS NOW?


A: No. If the merger of a partnership in which you own an interest is completed,
your certificates representing your partnership interests in that partnership
will be automatically cancelled. We will automatically mail certificates
representing Pioneer Parent common stock issued to you on completion of the
merger of that partnership.


Q: AM I ENTITLED TO APPRAISAL OR DISSENTERS' RIGHTS?

A: No. You will not have any appraisal or dissenters' rights in connection with
the merger of any partnership in which you own an interest.

Q: WHAT HAPPENS TO MY FUTURE CASH DISTRIBUTIONS?


A: Since your partnership interests in participating partnerships will be
cancelled upon completion of the merger of each such partnership, you will not
receive any future distributions on those interests. Pioneer Parent's board of
directors did not declare dividends to the holders of Pioneer Parent common
stock during 1999, 2000 or the three months ended March 31, 2001. The amount of
dividends, if any, paid by Pioneer Parent in the future will depend on business
conditions, its financial condition and earnings, and other factors.


Q: WHO CAN HELP ANSWER MY QUESTIONS?


A: If you have any questions about the merger of any of the partnerships in
which you own an interest, please call Pioneer Parent's information agent, D.F.
King & Co., Inc., at (XXX) XXX-XXXX.



                                      -iv-
   11
                                     SUMMARY


     To understand the merger of each partnership in which you own an interest
and to obtain a more detailed description of the legal terms of each such
merger, you should carefully read this entire document, the related partnership
supplements, and the documents described in "Where You Can Find More
Information" on the inside front cover page of this document . For definitions
of oil and gas terms used in this document, see "Commonly Used Oil and Gas
Terms" on page 81.



     When we use the terms "Pioneer USA," "we," "us" or "our," we are referring
to your sole or managing general partner, Pioneer Natural Resources USA, Inc.,
including its consolidated subsidiaries and predecessors, unless the context
otherwise requires. When we use the term "Pioneer Parent," we are referring to
Pioneer Natural Resources Company. When we use the term "merger proposals," we
are referring to the proposals to approve the merger agreement, the merger
amendment, the selection of special legal counsel for the limited partners and
the legal opinion of that counsel. When we use the term "participating
partnership," we are referring to each partnership the limited partners of which
approve the merger proposals.


                                   THE MERGERS


     Pioneer Parent proposes to acquire each partnership by merging each
partnership into us. We will be the survivor of each merger. The partnership
interests of each participating partnership, other than our interests, will be
converted into Pioneer Parent common stock.



     The number of shares of common stock Pioneer Parent will offer for all
partnership interests of a participating partnership will be based on (1) the
merger value for the partnership as described below and (2) the average closing
price of the Pioneer Parent common stock, as reported by the New York Stock
Exchange, for the ten trading days ending three business days before the initial
date of the special meeting for the partnership. Pioneer Parent and Pioneer USA
determined the merger value for each partnership primarily based on the present
value of estimated future net revenues from the partnership's estimated oil and
gas reserves at March 31, 2001, which was reviewed by Williamson Petroleum
Consultants, Inc. as of March 31, 2001. Pioneer Parent and Pioneer USA used
the following parameters in calculating the present value of estimated future
net revenues: (1) a five-year New York Mercantile Exchange, or NYMEX, futures
price for oil and gas as of March 30, 2001 with prices held constant after year
five at the year five price, less standard industry adjustments, (2) historical
operating costs adjusted only for those items affected by commodity prices, such
as production taxes and ad valorem taxes, and (3) a 10.0% discount rate. For
2001, the oil and gas prices were based on the average NYMEX futures price for
the nine-month period beginning on April 1, 2001 and ending December 31, 2001.
See the table on page 6 for the NYMEX futures prices. See "Method of Determining
Merger Value For Each Partnership and Amount of Pioneer Parent Common Stock
Offered -- Components of Merger Value For Each Partnership" on page 44 of this
document for information on the basis of pricing. In addition, each
partnership's merger value includes its net working capital as of March 31,
2001, less its pro rata share, based on its reserve value, of the estimated
expenses and fees of the mergers of all of the partnerships and less the cash
distribution to be mailed on or about July 12, 2001, by the partnership to its
partners. The Pioneer Parent common stock will be allocated among the partners
of a participating partnership based on the liquidation provisions of the
partnership agreement of the partnership.



     On pages 4 and 5 of this document is a table that shows important
information about each partnership, including the amount of Pioneer Parent
common stock that will be offered in the merger for each $1,000 of initial
investment for that partnership. For purposes of illustration in this document,
we have calculated the number of shares to be issued based on an assumed average
closing price of $18.00 per share of Pioneer Parent common stock. Prior to the
date of the special meeting for each partnership, we will update the number of
shares to be issued using the actual average closing price of Pioneer Parent
common stock for the ten trading days ending three business days before the
initial date of the special meeting.



     Pioneer Parent and Pioneer USA agreed to structure the transaction as a
merger of each partnership instead of as a property sale followed by liquidation
of each partnership because the merger will:


     o    require fewer legal documents;

     o    reduce filing fees and other costs; and


     o    result in the same amount of Pioneer Parent common stock to the
          limited partners as would a property sale and liquidation using the
          same commodity prices.



     Pioneer Parent and Pioneer USA expect to sign the merger agreement as soon
as the Securities and Exchange Commission declares effective under the
Securities Act of 1933 the registration statement that includes this document.
However, if the oil and gas commodity prices materially increase or decrease
from the prices used in calculating the merger value for any partnership,
Pioneer Parent or Pioneer USA might abandon the proposed merger of the
partnership before submitting the merger proposals to the limited partners for
approval. In addition, Pioneer Parent may abandon the proposed merger of any or
all of the partnerships at any time prior to the special meeting for any such
partnership for any reason including changes in, among other things, the price
of Pioneer Parent common stock, the market prices for oil and gas generally or
the oil and gas industry generally.




   12


                                  THE COMPANIES

PIONEER NATURAL RESOURCES COMPANY
1400 Williams Square West
5205 North O'Connor Blvd.
Irving, Texas 75039
(972) 444-9001


     Pioneer Parent is a large, independent exploration and production company
with total proved reserves equivalent to 3.8 trillion cubic feet of natural gas,
or 628 million barrels of oil. Pioneer Parent's proved reserves are balanced
equally between natural gas and oil, and Pioneer Parent has a
reserves-to-production ratio of 14 years. Sixty-seven percent of Pioneer
Parent's proved reserves are in three U.S. areas: the Hugoton gas field, the
West Panhandle gas field, and the Spraberry oil and natural gas field. Pioneer
Parent also has properties in East Texas, the Gulf Coast, and the offshore Gulf
of Mexico as well as in Argentina, Canada, South Africa, and Gabon. Pioneer
Parent seeks to increase net asset value and production by combining lower risk
development drilling with higher-risk exploration activity.



     Pioneer Parent's common stock is traded on the New York Stock Exchange and
the Toronto Stock Exchange under the symbol "PXD." Pioneer Parent prepared this
document to offer its common stock to you. See "Pioneer Parent" on page 69 of
this document for more information about Pioneer Parent.



     Pioneer Parent files annual, quarterly and special reports, proxy
statements and other information with the Securities and Exchange Commission.
Those SEC filings are available to you in the same manner as each reporting
partnership's information. See "Where You Can Find More Information" on the
inside front cover page of this document.


PIONEER NATURAL RESOURCES USA, INC.
1400 Williams Square West
5205 North O'Connor Blvd.
Irving, Texas 75039
(972) 444-9001


     We prepared this document to solicit your proxy. We are a 100% owned
subsidiary of Pioneer Parent. We directly own almost all of Pioneer Parent's
United States oil and gas properties.


THE PARTNERSHIPS
c/o Pioneer Natural Resources USA, Inc.
1400 Williams Square West
5205 North O'Connor Blvd.
Irving, Texas 75039
(972) 444-9001


     The name of each partnership is found in the table beginning on page 4.
Each partnership produces and sells oil and gas. Each partnership was formed to
provide the general and limited partners cash flow from operations and, except
for Parker & Parsley Producing Properties 87-A, Ltd., Parker & Parsley Producing
Properties 87-B, Ltd. and Parker & Parsley Producing Properties 88-A, L.P., a
one time deduction for intangible drilling and development costs. See the
supplement to this document for each of your partnerships for specific
information about the partnership, including the merger value as a multiple of
distributions for the past four quarterly distributions including the
distribution in July 2001. As a result of each partnership's oil and gas
operations, each partnership distributes cash to the limited and general
partners from the partnership's net cash flows. These distributions are made
quarterly, unless sufficient cash is not available.



     The partnerships' properties consist of interests in approximately 1,100
oil and gas wells that are located primarily in the Spraberry field of the
Permian Basin of West Texas. We operate approximately 92% of the partnerships'
wells. At December 31, 2000, the partnerships' combined total proved reserves
were 33.6 million barrels of oil equivalent, or MMBOE, consisting of 27.3
million barrels, or MMBbls, of oil and natural gas liquids and 37.6 billion
cubic feet, or Bcf, of natural gas. Approximately 93% of the reserves are
attributable to the limited partners' partnership interests, excluding
partnership interests we directly own. Approximately 81% of the total proved
reserves attributable to the properties are oil and liquids, and 19% are natural
gas, based on six Mcf of gas being equivalent to one Bbl of oil. See "The
Partnerships" on page 71 of this document for more information about the
partnerships.



                                  RISK FACTORS



     You should carefully consider the risks relating to the merger of each
partnership in which you own an interest described in "Risk Factors" beginning
on page 17 of this document. These include:



o    The merger value for the partnership determines the amount of Pioneer
     Parent common stock you will receive in the merger of the partnership.
     Pioneer Parent and Pioneer USA determined each merger value and will not
     adjust it for changes in partnership value before the merger is completed.



o    You were not independently represented in establishing the terms of any
     merger.



o    Our board of directors had conflicting interests in evaluating each merger
     because each member of our board of directors is also an officer of Pioneer
     Parent.



o    Repurchase offers in 2001 by each of the six partnerships with a repurchase
     obligation were higher than the merger value for the partnership.



o    Limited partners who become Pioneer Parent stockholders will own stock in a
     corporation rather than a limited partnership interest in a limited
     partnership resulting in a fundamental change in the nature of their
     investments.


                        SUMMARY TABLE -- MERGER VALUE AND
                        AMOUNT OF INITIAL LIMITED PARTNER
                                INVESTMENT REPAID

     The table on pages 4 and 5 contains the following summary information for
each partnership:


                                      -2-
   13


o    the merger value attributable to:


     -    Pioneer USA's partnership interests, whether general or limited;

     -    the partnership interests of the unaffiliated limited partners of the
          nonmanaging general partner, if any, of each partnership;


     -    the limited partners' partnership interests, including the estimated
          number of shares of Pioneer Parent common stock offered to the limited
          partners other than Pioneer USA;


o    for each $1,000 initial limited partner investment in the partnership:


     -    the estimated number of shares of Pioneer Parent common stock offered;


     -    the merger value;


     -    the total historical cash distributions through July 31, 2001; and


     -    the total amount of initial investment by the limited partners that
          has been repaid, after giving effect to the merger of the partnership,
          stated in dollars and as a percentage; and

o    the aggregate reserve value attributable to the limited partners other than
     Pioneer USA per barrel of oil equivalent, or BOE.


     This information is based on assumptions, including the following:



o    Pioneer Parent and Pioneer USA engaged Williamson Petroleum Consultants,
     Inc. to review the estimates of each partnership's reserves as of March 31,
     2001.



o    Pioneer Parent and Pioneer USA estimated the present value of estimated
     future net revenues for each partnership from the estimated reserves for
     each partnership at March 31, 2001. Pioneer Parent and Pioneer USA used the
     following parameters in calculating the present value of estimated future
     net revenues: (1) a five-year NYMEX futures price for oil and gas as of
     March 30, 2001, with prices held constant after year five at the year five
     price, less standard industry adjustments, (2) historical operating costs
     adjusted only for those items affected by commodity prices, such as
     production taxes and ad valorem taxes, and (3) a discount rate of 10.0%.



See "Method of Determining Merger Value for Each Partnership and Amount of
Pioneer Parent Common Stock Offered - Components of Merger Value for Each
Partnership."



     You should read the following table together with the detailed information
in Table 2 and Table 3 of Appendix A to this document. For purposes of
illustration in this document, we have calculated the number of shares to be
issued based on an assumed average closing price of $18.00 per share of Pioneer
Parent common stock. Prior to the date of the special meeting for each
partnership, we will update the number of shares to be issued using the actual
average closing price of Pioneer Parent common stock for the ten trading days
ending three business days before the initial date of the special meeting.


     Interests in some partnerships were sold in units at prices other than
$1,000. We have presented this information based on a $1,000 initial investment
for ease of use and comparison among partnerships. You should not assume that
the amount shown per $1,000 investment is the same as the value or amount
attributable to a single unit investment. See Table 1 of Appendix A to this
document for the initial subscription price for each unit.


                                      -3-
   14

           SUMMARY TABLE -- MERGER VALUE AND AMOUNT OF INITIAL LIMITED
                            PARTNER INVESTMENT REPAID





                                                      ------------------------------------------------------------------------------
                                                                                     MERGER VALUE
                                                      ------------------------------------------------------------------------------
                                                                                                    LIMITED PARTNERS
                                                                                     -----------------------------------------------
                                                                      NONMANAGING
                                                         PIONEER        GENERAL
                                                           USA          PARTNERS
                                                      -------------  -------------     AGGREGATE          LESS
                                                          MERGER         MERGER          MERGER         JULY 2001         MERGER
                                                          VALUE          VALUE           VALUE        DISTRIBUTIONS        VALUE
                                                      -------------  -------------   -------------    -------------    -------------
                                                                                                        
PARKER & PARSLEY 81-I, LTD.                           $     225,691  $      16,187   $     680,747    $     (51,812)   $     628,935
PARKER & PARSLEY 81-II, LTD.                                142,209          5,774         510,262          (40,512)         469,750
PARKER & PARSLEY 82-I, LTD.                                 384,588         13,293         921,471          (77,867)         843,604
PARKER & PARSLEY 82-II, LTD.                                417,948         12,957       1,258,424          (59,442)       1,198,982
PARKER & PARSLEY 82-III, LTD.                               305,950          9,928         837,663          (49,940)         787,723
PARKER & PARSLEY 83-A, LTD.                                 940,944         37,001       2,824,140         (161,154)       2,662,986
PARKER & PARSLEY 83-B, LTD.                               1,233,793         48,095       3,657,507         (184,534)       3,472,973
PARKER & PARSLEY 84-A, LTD.                               1,285,776         56,545       4,068,298         (237,861)       3,830,437
PARKER & PARSLEY 85-A, LTD.                                  41,068             --       1,450,480          (87,918)       1,362,562
PARKER & PARSLEY 85-B, LTD.                                  20,207             --       1,232,802          (77,401)       1,155,401
PARKER & PARSLEY PRIVATE INVESTMENT 85-A, LTD.               50,076             --       1,514,330          (81,105)       1,433,225
PARKER & PARSLEY SELECTED 85 PRIVATE INVESTMENT, LTD.        24,401             --         960,832          (77,690)         883,142
PARKER & PARSLEY 86-A, LTD.                                  24,320             --       1,798,787          (10,918)       1,787,869
PARKER & PARSLEY 86-B, LTD.                                  67,657             --       4,055,061         (226,314)       3,828,747
PARKER & PARSLEY 86-C, LTD.                                  41,133             --       3,381,735         (276,941)       3,104,794
PARKER & PARSLEY PRIVATE INVESTMENT 86, LTD.                 12,640             --       1,334,081          (82,767)       1,251,314
PARKER & PARSLEY 87-A CONV., LTD.                            14,150             --         788,572          (57,434)         731,138
PARKER & PARSLEY 87-A, LTD.                                  88,920             --       5,894,403         (430,459)       5,463,944
PARKER & PARSLEY 87-B CONV., LTD.                            12,012             --       1,051,036          (63,086)         987,950
PARKER & PARSLEY 87-B, LTD.                                  49,926             --       4,294,068         (257,587)       4,036,481
PARKER & PARSLEY PRODUCING PROPERTIES 87-A, LTD.             35,132             --       2,816,163         (246,164)       2,569,999
PARKER & PARSLEY PRODUCING PROPERTIES 87-B, LTD.             62,154             --       2,452,316         (116,244)       2,336,072
PARKER & PARSLEY PRIVATE INVESTMENT 87, LTD.                 29,502             --       3,127,660         (206,933)       2,920,727
PARKER & PARSLEY 88-A CONV., L.P.                            21,672             --         994,896          (76,370)         918,526
PARKER & PARSLEY 88-A, L.P.                                  74,684             --       3,399,201         (260,389)       3,138,812
PARKER & PARSLEY 88-B CONV., L.P.                            18,200             --       1,227,494          (67,356)       1,160,138
PARKER & PARSLEY 88-B, L.P.                                  59,211             --       3,009,326         (165,038)       2,844,288



                                                       -----------------    ---------------------------------------------
                                                         MERGER VALUE       PER $1,000 INITIAL LIMITED PARTNER INVESTMENT
                                                       -----------------    ---------------------------------------------
                                                       LIMITED PARTNERS
                                                       -----------------
                                                           ESTIMATED          ESTIMATED
                                                            NUMBER OF           NUMBER OF                  DISTRIBUTIONS
                                                            SHARES OF           SHARES OF                      FROM
                                                             PIONEER             PIONEER                     INCEPTION
                                                             COMMON              COMMON          MERGER       THROUGH
                                                        STOCK OFFERED(a)    STOCK OFFERED(a)      VALUE       7/31/01
                                                        ----------------    ----------------   ----------   ----------
                                                                                                
PARKER & PARSLEY 81-I, LTD.                                  34,941                5.01        $    90.13   $   657.13
PARKER & PARSLEY 81-II, LTD.                                 26,098                4.07             73.34       841.87
PARKER & PARSLEY 82-I, LTD.                                  46,867                4.45             80.06       985.93
PARKER & PARSLEY 82-II, LTD.                                 66,611                5.65            101.61     1,141.98
PARKER & PARSLEY 82-III, LTD.                                43,763                6.76            121.72       985.34
PARKER & PARSLEY 83-A, LTD.                                 147,944                7.86            141.43     1,328.26
PARKER & PARSLEY 83-B, LTD.                                 192,943                8.58            154.41     1,532.16
PARKER & PARSLEY 84-A, LTD.                                 212,803               11.19            201.43     1,471.45
PARKER & PARSLEY 85-A, LTD.                                  75,698                8.03            144.55       757.31
PARKER & PARSLEY 85-B, LTD.                                  64,189                8.09            145.70       954.81
PARKER & PARSLEY PRIVATE INVESTMENT 85-A, LTD.               79,624               16.32            293.69     1,131.64
PARKER & PARSLEY SELECTED 85 PRIVATE INVESTMENT, LTD.        49,064               10.64            191.57       967.15
PARKER & PARSLEY 86-A, LTD.                                  99,327                9.84            177.09     1,360.62
PARKER & PARSLEY 86-B, LTD.                                 212,709               12.45            224.17     1,575.72
PARKER & PARSLEY 86-C, LTD.                                 172,489                8.96            161.23     1,486.92
PARKER & PARSLEY PRIVATE INVESTMENT 86, LTD.                 69,518               14.13            254.33     1,634.33
PARKER & PARSLEY 87-A CONV., LTD.                            40,619               10.63            191.35     1,332.03
PARKER & PARSLEY 87-A, LTD.                                 303,553               10.60            190.81     1,332.10
PARKER & PARSLEY 87-B CONV., LTD.                            54,887               11.18            201.25     1,251.46
PARKER & PARSLEY 87-B, LTD.                                 224,249               11.19            201.38     1,251.53
PARKER & PARSLEY PRODUCING PROPERTIES 87-A, LTD.            142,778               11.73            211.17     1,000.38
PARKER & PARSLEY PRODUCING PROPERTIES 87-B, LTD.            129,782               21.64            389.51     1,127.05
PARKER & PARSLEY PRIVATE INVESTMENT 87, LTD.                162,263               15.48            278.69     1,575.74
PARKER & PARSLEY 88-A CONV., L.P.                            51,030               13.63            245.40     1,120.44
PARKER & PARSLEY 88-A, L.P.                                 174,379               13.66            245.95     1,120.54
PARKER & PARSLEY 88-B CONV., L.P.                            64,453               17.82            320.83     1,129.70
PARKER & PARSLEY 88-B, L.P.                                 158,016               17.83            321.02     1,129.74


                                                    --------------------------
                                                       PER $1,000 INITIAL
                                                    LIMITED PARTNER INVESTMENT
                                                    --------------------------



                                                             AMOUNT OF            LIMITED
                                                        INITIAL INVESTMENT       PARTNERS'
                                                               REPAID            AGGREGATE
                                                       ---------------------   RESERVE VALUE
                                                           $            %         PER BOE
                                                       ----------    -------   -------------
                                                                      
PARKER & PARSLEY 81-I, LTD.                            $   747.26     74.73%      $  3.92
PARKER & PARSLEY 81-II, LTD.                               915.21     91.52%         3.42
PARKER & PARSLEY 82-I, LTD.                              1,065.99    106.60%         3.50
PARKER & PARSLEY 82-II, LTD.                             1,243.59    124.36%         4.05
PARKER & PARSLEY 82-III, LTD.                            1,107.06    110.71%         3.83
PARKER & PARSLEY 83-A, LTD.                              1,469.69    146.97%         3.53
PARKER & PARSLEY 83-B, LTD.                              1,686.57    168.66%         3.53
PARKER & PARSLEY 84-A, LTD.                              1,672.88    167.29%         3.55
PARKER & PARSLEY 85-A, LTD.                                901.86     90.19%         3.82
PARKER & PARSLEY 85-B, LTD.                              1,100.51    110.05%         4.01
PARKER & PARSLEY PRIVATE INVESTMENT 85-A, LTD.           1,425.33    142.53%         4.39
PARKER & PARSLEY SELECTED 85 PRIVATE INVESTMENT, LTD.    1,158.72    115.87%         3.81
PARKER & PARSLEY 86-A, LTD.                              1,537.71    153.77%         3.80
PARKER & PARSLEY 86-B, LTD.                              1,799.89    179.99%         4.14
PARKER & PARSLEY 86-C, LTD.                              1,648.15    164.82%         3.76
PARKER & PARSLEY PRIVATE INVESTMENT 86, LTD.             1,888.66    188.87%         4.00
PARKER & PARSLEY 87-A CONV., LTD.                        1,523.38    152.34%         4.03
PARKER & PARSLEY 87-A, LTD.                              1,522.91    152.29%         4.06
PARKER & PARSLEY 87-B CONV., LTD.                        1,452.71    145.27%         3.92
PARKER & PARSLEY 87-B, LTD.                              1,452.91    145.29%         3.92
PARKER & PARSLEY PRODUCING PROPERTIES 87-A, LTD.         1,211.55    121.16%         3.90
PARKER & PARSLEY PRODUCING PROPERTIES 87-B, LTD.         1,516.56    151.66%         4.19
PARKER & PARSLEY PRIVATE INVESTMENT 87, LTD.             1,854.43    185.44%         3.87
PARKER & PARSLEY 88-A CONV., L.P.                        1,365.84    136.58%         4.04
PARKER & PARSLEY 88-A, L.P.                              1,366.49    136.65%         4.04
PARKER & PARSLEY 88-B CONV., L.P.                        1,450.53    145.05%         4.21
PARKER & PARSLEY 88-B, L.P.                              1,450.76    145.08%         4.21




                                      -4-
   15





                                                      ------------------------------------------------------------------------------
                                                                                     MERGER VALUE
                                                      ------------------------------------------------------------------------------
                                                                                                    LIMITED PARTNERS
                                                                                     -----------------------------------------------
                                                                      NONMANAGING
                                                         PIONEER        GENERAL
                                                           USA          PARTNERS
                                                      -------------  -------------     AGGREGATE          LESS
                                                          MERGER         MERGER          MERGER         JULY 2001         MERGER
                                                          VALUE          VALUE           VALUE        DISTRIBUTIONS        VALUE
                                                      -------------  -------------   -------------    -------------    -------------
                                                                                                        
PARKER & PARSLEY 88-C CONV., L.P.                            12,256             --         996,336          (58,700)         937,636
PARKER & PARSLEY 88-C, L.P.                                   8,093             --         706,148          (41,872)         664,276
PARKER & PARSLEY PRODUCING PROPERTIES 88-A, L.P.             34,210             --       2,107,964         (115,652)       1,992,312
PARKER & PARSLEY PRIVATE INVESTMENT 88, L.P.                 34,558             --       3,624,600         (203,402)       3,421,198
PARKER & PARSLEY 89-A CONV., L.P.                             9,323             --         981,521          (58,543)         922,978
PARKER & PARSLEY 89-A, L.P.                                  62,481             --       2,886,522         (171,882)       2,714,640
PARKER & PARSLEY 89-B CONV., L.P.                            23,671             --       1,897,795         (119,915)       1,777,880
PARKER & PARSLEY 89-B, L.P.                                  40,152             --       2,073,108         (131,168)       1,941,940
PARKER & PARSLEY PRIVATE INVESTMENT 89, L.P.                 30,131             --       2,028,263         (128,040)       1,900,223
PARKER & PARSLEY 90-A CONV., L.P.                             9,110             --         608,388          (43,633)         564,755
PARKER & PARSLEY 90-A, L.P.                                  52,103             --       1,732,967         (123,996)       1,608,971
PARKER & PARSLEY 90-B CONV., L.P.                            53,040             --       3,371,528         (240,352)       3,131,176
PARKER & PARSLEY 90-B, L.P.                                 108,517             --       9,195,042         (654,545)       8,540,497
PARKER & PARSLEY 90-C CONV., L.P.                            25,877             --       1,944,137         (114,157)       1,829,980
PARKER & PARSLEY 90-C, L.P.                                  36,317             --       3,122,419         (183,844)       2,938,575
PARKER & PARSLEY PRIVATE INVESTMENT 90, L.P.                 53,018             --       3,609,423         (222,982)       3,386,441
PARKER & PARSLEY 90 SPRABERRY PRIVATE DEV., L.P.             15,154             --       1,616,753         (116,477)       1,500,276
PARKER & PARSLEY 91-A, L.P.                                  65,151             --       4,950,064         (305,711)       4,644,353
PARKER & PARSLEY 91-B, L.P.                                  54,733             --       5,259,991         (284,171)       4,975,820
                                                      -------------  -------------   -------------    -------------    -------------
                                                      $   6,411,859  $     199,780   $ 112,254,724    $  (7,050,278)   $ 105,204,446
                                                      =============  =============   =============    =============    =============





                                                       -----------------    ---------------------------------------------
                                                         MERGER VALUE       PER $1,000 INITIAL LIMITED PARTNER INVESTMENT
                                                       -----------------    ---------------------------------------------
                                                       LIMITED PARTNERS
                                                       -----------------
                                                           ESTIMATED          ESTIMATED
                                                            NUMBER OF           NUMBER OF                  DISTRIBUTIONS
                                                            SHARES OF           SHARES OF                      FROM
                                                             PIONEER             PIONEER                     INCEPTION
                                                             COMMON              COMMON          MERGER       THROUGH
                                                        STOCK OFFERED(a)    STOCK OFFERED(a)      VALUE       7/31/01
                                                        ----------------    ----------------   ----------   ----------
                                                                                                
PARKER & PARSLEY 88-C CONV., L.P.                            52,091               15.32            275.69     1,052.80
PARKER & PARSLEY 88-C, L.P.                                  36,905               15.21            273.81     1,052.39
PARKER & PARSLEY PRODUCING PROPERTIES 88-A, L.P.            110,684               19.86            357.55     1,234.73
PARKER & PARSLEY PRIVATE INVESTMENT 88, L.P.                190,067               19.08            343.50     1,185.95
PARKER & PARSLEY 89-A CONV., L.P.                            51,277               18.33            329.99     1,070.24
PARKER & PARSLEY 89-A, L.P.                                 150,814               18.37            330.57     1,070.30
PARKER & PARSLEY 89-B CONV., L.P.                            98,772               15.71            282.79       931.42
PARKER & PARSLEY 89-B, L.P.                                 107,886               15.69            282.39       931.43
PARKER & PARSLEY PRIVATE INVESTMENT 89, L.P.                105,568               15.04            270.69       800.47
PARKER & PARSLEY 90-A CONV., L.P.                            31,376               13.38            240.83       909.70
PARKER & PARSLEY 90-A, L.P.                                  89,388               13.41            241.44       909.76
PARKER & PARSLEY 90-B CONV., L.P.                           173,955               14.72            264.97       736.72
PARKER & PARSLEY 90-B, L.P.                                 474,473               14.74            265.39       736.80
PARKER & PARSLEY 90-C CONV., L.P.                           101,666               13.55            243.96       657.33
PARKER & PARSLEY 90-C, L.P.                                 163,255               13.51            243.26       657.33
PARKER & PARSLEY PRIVATE INVESTMENT 90, L.P.                188,136               17.24            310.40       823.21
PARKER & PARSLEY 90 SPRABERRY PRIVATE DEV., L.P.             83,349               16.03            288.51       760.35
PARKER & PARSLEY 91-A, L.P.                                 258,020               22.29            401.24       854.43
PARKER & PARSLEY 91-B, L.P.                                 276,435               24.60            442.73       737.60
                                                          ---------              ------        ----------   ----------
                                                          5,844,714              613.50        $11,043.53   $49,296.29
                                                          =========              ======        ==========   ==========


                                                    --------------------------
                                                       PER $1,000 INITIAL
                                                    LIMITED PARTNER INVESTMENT
                                                    --------------------------



                                                             AMOUNT OF            LIMITED
                                                        INITIAL INVESTMENT       PARTNERS'
                                                               REPAID            AGGREGATE
                                                       ---------------------   RESERVE VALUE
                                                           $            %         PER BOE
                                                       ----------    -------   -------------
                                                                      

PARKER & PARSLEY 88-C CONV., L.P.                        1,328.49    132.85%         4.13
PARKER & PARSLEY 88-C, L.P.                              1,326.20    132.62%         4.13
PARKER & PARSLEY PRODUCING PROPERTIES 88-A, L.P.         1,592.28    159.23%         4.23
PARKER & PARSLEY PRIVATE INVESTMENT 88, L.P.             1,529.45    152.95%         4.33
PARKER & PARSLEY 89-A CONV., L.P.                        1,400.23    140.02%         4.35
PARKER & PARSLEY 89-A, L.P.                              1,400.87    140.09%         4.35
PARKER & PARSLEY 89-B CONV., L.P.                        1,214.21    121.42%         4.08
PARKER & PARSLEY 89-B, L.P.                              1,213.82    121.38%         4.08
PARKER & PARSLEY PRIVATE INVESTMENT 89, L.P.             1,071.16    107.12%         4.27
PARKER & PARSLEY 90-A CONV., L.P.                        1,150.53    115.05%         4.19
PARKER & PARSLEY 90-A, L.P.                              1,151.20    115.12%         4.19
PARKER & PARSLEY 90-B CONV., L.P.                        1,001.69    100.17%         4.26
PARKER & PARSLEY 90-B, L.P.                              1,002.19    100.22%         4.25
PARKER & PARSLEY 90-C CONV., L.P.                          901.29     90.13%         4.19
PARKER & PARSLEY 90-C, L.P.                                900.59     90.06%         4.19
PARKER & PARSLEY PRIVATE INVESTMENT 90, L.P.             1,133.61    113.36%         4.34
PARKER & PARSLEY 90 SPRABERRY PRIVATE DEV., L.P.         1,048.86    104.89%         3.78
PARKER & PARSLEY 91-A, L.P.                              1,255.67    125.57%         4.52
PARKER & PARSLEY 91-B, L.P.                              1,180.33    118.03%         4.61
                                                       ----------
                                                       $60,339.82
                                                       ==========




---------------

(a)  For this preliminary document, the number of shares of Pioneer common stock
     offered is based upon an assumed average closing price of $18.00 per share
     of Pioneer common stock.

                                      -5-
   16
                              NYMEX FUTURES PRICES

     The following table shows the NYMEX futures price for oil and gas as of
March 30, 2001, which Pioneer Parent and Pioneer USA used in the calculation of
the reserve value portion of the merger value for each partnership:



         DATE               OILS ($/Bbl)        GAS ($/Mcf)(1)
    --------------          ------------        --------------
                                          
    Apr - Dec 2001             26.17                  5.18
         2002                  24.36                  4.61
         2003                  22.83                  4.16
         2004                  22.31                  4.09
         2005                  21.97                  4.12
      Thereafter               21.97                  4.12


----------

(1)  The NYMEX price for gas is quoted in dollars per million British thermal
     units, or MMBTU. We converted those prices to dollars per thousand cubic
     feet, or Mcf.

     The reserve value portion of the merger value for each partnership was
calculated using a 10.0% discount rate.

       EXAMPLE CALCULATION OF MERGER VALUE FOR PARKER & Parsley 81-I, Ltd.



                                                                            
Merger value for limited partners:
     Reserve value (Table 16 of Appendix A to this document)   (1)    $   627,135
     Plus working capital value                                (2)         65,041
     Less estimated merger expenses and fees                   (3)        (11,429)
                                                                      -----------
     Aggregate merger value (page 4 of this document)                     680,747
     Less July 2001 distribution                               (4)        (51,812)
                                                                      -----------
     Merger value (page 4 of this document and Table 2 of
     Appendix A to this document)                              (5)    $   628,935
                                                                      ===========

Initial investment:
     Initial investment by limited partners (Table 1 of
     Appendix A to this document)                                     $ 7,410,000
     Less initial investment by Pioneer USA (Table 6 of
     Appendix A to this document)                                         433,000
                                                                      -----------
     Initial investment without Pioneer USA                           $ 6,977,000
                                                                      ===========

Number of per $1,000 limited partner investments:              (6)          6,977
                                                                      ===========

Per $1,000 limited partner investment as set forth in Table
3 of Appendix A to this document:
     Reserve value                                                    $     89.88   (1) divided by (6)
     Working capital value                                                   9.32   (2) divided by (6)
     Less estimated merger expenses and fees                                (1.64)  (3) divided by (6)
                                                                      -----------
     Aggregate merger value                                                 97.56
     Less July 2001 distribution                                            (7.43)  (4) divided by (6)
                                                                      -----------
     Merger value                                                     $     90.13
                                                                      ===========

Aggregate number of shares of Pioneer Parent common stock
offered to limited partners of the partnership before
rounding                                                                34,940.83   (5) divided by $18.00
                                                                      ===========
Aggregate number of shares of Pioneer Parent common stock
offered to limited partners of the partnership rounded up to
the nearest whole share                                        (7)         34,941
                                                                      ===========

Number of shares of Pioneer Parent common stock offered per
$1,000 limited partner investment                                            5.01   (7) divided by (6)
                                                                      ===========




                                      -6-
   17



               BENEFITS AND DISADVANTAGES TO THE LIMITED PARTNERS


     We believe the merger of each partnership provides the following benefits
to the limited partners of the partnership:

     Liquidity. None of the partnership interests of any of the partnerships are
traded on a national stock exchange or in any other significant market. No
liquid market exists for interests in any of the partnerships. Although some
partnership interests are occasionally sold in private or an informal secondary
market for limited partner securities, we believe the potential buyers in such
transactions are few and the prices generally reflect a significant discount for
illiquidity. See Table 15 of Appendix A for historical information about recent
trades of partnership interests in each partnership. Repurchase obligations
exist in only a few of the partnerships and are limited in both amount and price
by formula in the partnership agreements. See Table 8 of Appendix A for
repurchase information.


     The merger of each partnership provides liquidity to the limited partners
of that partnership at a price based on oil and gas reserve values, not on
limited market demand for illiquid partnership interests. All limited partners
of a participating partnership will receive Pioneer Parent common stock in
exchange for their partnership interests shortly after completion of the merger
of the partnership. Shares of Pioneer Parent common stock are freely
transferable and listed on the New York Stock Exchange and the Toronto Stock
Exchange. On April 16, 2001, the last full trading day prior to the announcement
of the proposed merger of each partnership, the last reported sales price of
Pioneer Parent common stock, as reported by the New York Stock Exchange, was
$17.27.



     Oil and Gas Investment Vehicle. Pioneer Parent's common stock provides an
oil and gas investment vehicle that we believe will be advantageous to the
partnership interests in each partnership because:



o    Expansion and Balancing of Reserves. The limited partners will have the
     opportunity to benefit from Pioneer Parent's efforts (1) to expand its
     reserve base through acquisitions and development or exploratory drilling,
     and (2) to maintain a strategic balance between oil and natural gas
     reserves. At December 31, 2000, Pioneer Parent's reserve mix was 50% oil
     and NGLs and 50% natural gas compared to the combined partnerships' reserve
     mix of 81% oil and NGLs and 19% natural gas at such date.



o    Geographic Diversification and Larger Oil and Gas Reserve Base. By
     combining each participating partnership into a single ownership entity,
     the merger of the partnership provides the limited partners of the
     partnership with an investment portfolio substantially larger and more
     geographically diversified than the portfolio of the partnership
     individually. This increased size and the resulting consolidation of
     operations spread the risk of an investment in Pioneer Parent over a
     broader group of assets and reduces the dependence of the investment upon
     the performance of any particular asset or group of assets, such as assets
     in the same geographical area.



     Liquidation Value. The merger value for each partnership is based on the
value of the underlying properties, which we believe is essentially the same
value or a higher value than that could be achieved by selling the partnership's
property interests and liquidating the partnership at that time. In addition, we
believe that the value of Pioneer Parent common stock to be distributed to each
limited partner in the merger of each partnership is higher than what the
limited partners would otherwise receive over the life of the partnership,
assuming the same oil and gas commodity prices and operating costs as used to
determine the reserve value for each partnership and giving effect to the time
value of money, for the following reasons:


o    The partnership agreement for each partnership requires cash distributions
     to be reduced by general and administrative expenses allocable to the
     partnership. The merger value for each partnership reflects a liquidation
     value based on a reserve value that has not been reduced for general and
     administrative expenses.


o    The merger value for each partnership is based primarily upon the reserve
     value for the partnership, which was determined using recent NYMEX futures
     oil and gas prices that are, on average, higher than historical oil and gas
     prices. It is likely that actual oil and gas prices will vary often and
     possibly widely, as has been demonstrated historically, from the prices
     used to prepare these estimates. Although future oil and gas prices could
     be higher than the prices on March 30, 2001 which were used in calculating
     the merger value for each partnership, using a fixed date for determining
     the merger value for each partnership eliminates the potential loss in
     value that could occur if oil and gas prices decline.



     Acceleration of Realization of Value. Pioneer Parent's common stock
provides the limited partners of each participating partnership with liquidity
earlier than if the limited partners remain in the partnership and receive the
expected ordinary cash distributions from oil and gas production. Because each
partnership's properties are mature producing properties, we believe that
production from those properties will continue to decline at the rate predicted
in the partnership's oil and gas engineering reserve reports. Accordingly, cash
distributions from each partnership are also expected to decline, subject to
variation for changes in oil and gas prices.


     Elimination of Partnership Tax Reports. The merger of each participating
partnership will eliminate the limited partners' Schedule K-1 tax reports for
the partnership for tax years after the merger occurs. This is expected to
simplify the limited partners' individual tax return preparation and reduce
preparation costs.


     We also considered the following disadvantages of the merger of each
partnership:



                                      -7-
   18


o    Limited partners of each partnership will own stock in a corporation which
     is a different investment objective from investing in a partnership
     designed to generate recurring cash distributions.



o    Limited partners who become Pioneer Parent stockholders will no longer
     receive partnership cash distributions.



o    Pioneer Parent will engage in the acquisition, exploration and development
     of new oil and gas properties which will expose limited partners of each
     partnership to all of the attendant risks associated with such activities.
     Each partnership owns producing properties and does not conduct drilling
     activities. Pioneer Parent's activities may, therefore, involve greater
     risks than the activities of each partnership, but also offer the potential
     for additional benefits if the acquisition and exploitation activities are
     successful.



o    Increases in prices for oil and gas may have a more direct effect on
     limited partners of each partnership due to the immediate effect on
     potential cash distributions. However, we believe that an increase in oil
     and gas prices will also have an indirect beneficial effect on the market
     price for Pioneer Parent common stock.



o    Limited partners who become Pioneer Parent stockholders will be subject to
     the volatility of the market value of Pioneer Parent common stock. Market
     factors that may affect the common stock price will include factors other
     than those that affect the value of a limited partner's interest in a
     partnership, such as general market conditions.



o    Limited partners who become Pioneer Parent stockholders may have to
     recognize a taxable gain on the transaction.


                                FRACTIONAL SHARES


     Pioneer Parent will not issue fractional shares to any limited partner upon
completion of the merger of any partnership. Instead, Pioneer Parent will round
any fractional shares of Pioneer Parent common stock up to the nearest whole
share.




                       RECOMMENDATION TO LIMITED PARTNERS
                                  (SEE PAGE 32)



     On           , 2001, our board of directors unanimously determined that the
merger of each partnership in which you own an interest is advisable, fair to
you, as an unaffiliated limited partner, and in your best interests. Our board
recommends that you, as an unaffiliated limited partner, vote for the merger
proposals for each partnership in which you own an interest. Although our board
of directors has attempted to fulfill its fiduciary duties to you, our board of
directors had conflicting interests in evaluating each merger because each
member of our board of directors is also an officer of Pioneer Parent.


                                    FAIRNESS

     In deciding to approve the merger of each partnership on                ,
2001, our board of directors decided that each merger of a partnership in which
you own an interest is advisable, fair to you, as an unaffiliated limited
partner, and in your best interests based on a variety of factors. These factors
include:

o    the form and amount of consideration offered to you;


o    the comparison of the amount of Pioneer Parent common stock offered in each
     merger to the future cash distributions otherwise expected as oil and gas
     production continues to decline and general and administrative expenses
     continue to be incurred;


o    the elimination after the merger of each participating partnership of its
     limited partners' tax preparation costs relating to partnership tax
     information;


o    the belief that the price offered by Pioneer Parent is a competitive price
     because of:


     -    the commodity pricing used in determining the merger value for each
          partnership;

     -    Pioneer USA's position as operator of most of each partnership's
          wells; and

     -    Pioneer USA's significant ownership of nearby properties; and

o    the fairness opinion from Stanger.


                      FAIRNESS OPINION OF FINANCIAL ADVISOR
                                  (SEE PAGE 33)



     Stanger has issued a fairness opinion dated        , 2001, that, subject
to the qualifications expressed in the opinion, the merger value for each
partnership and the allocation of the merger value of the partnership (1) to the
limited partners of the partnership as a group, (2) to the general partners of
the partnership as a group, (3) to Pioneer USA as the managing or sole general
partner of the partnership, (4) to the unaffiliated limited partners of the
partnership as a group and (5) to the unaffiliated limited partners of the
nonmanaging general partner, if any, of the partnership as a group, is fair to
the unaffiliated limited partners of the partnership and the unaffiliated
limited partners of the nonmanaging general partner, if any, of the partnership,
from a financial point of view. The full text of the form of written opinion of
Stanger is attached to this document as Appendix D. You should read all of it
carefully. THE OPINION OF STANGER IS DIRECTED TO OUR BOARD OF DIRECTORS. IT IS
NOT A RECOMMENDATION TO YOU ABOUT HOW YOU SHOULD VOTE ON MATTERS RELATING TO THE
PROPOSED MERGER OF ANY PARTNERSHIP IN WHICH YOU OWN AN INTEREST.



                          MATERIAL U.S. FEDERAL INCOME
                                TAX CONSEQUENCES
                                  (SEE PAGE 48)



     You will generally recognize gain or loss equal to the difference between
(1) the value of the Pioneer



                                      -8-
   19



Parent common stock you receive in the merger of each partnership in which you
own interests and (2) your adjusted tax basis in your partnership interests in
that participating partnership. Your gain or loss will be capital or ordinary
depending on the nature of the assets held by each participating partnership in
which you own an interest and the amount of depletion and intangible drilling
and development costs that must be recaptured. You must calculate your ordinary
and capital gain or loss separately for each partnership in which you own an
interest.



     TAX MATTERS ARE VERY COMPLICATED. THE TAX CONSEQUENCES TO YOU OF EACH
MERGER OF A PARTNERSHIP IN WHICH YOU OWN AN INTEREST WILL DEPEND ON THE FACTS OF
YOUR OWN SITUATION. YOU SHOULD SEEK TAX ADVICE FOR A FULL UNDERSTANDING OF THE
PARTICULAR TAX CONSEQUENCES OF EACH SUCH MERGER TO YOU.


                       CERTIFICATION OF NON-FOREIGN STATUS


     YOUR CERTIFICATE THAT YOU ARE NOT A FOREIGN PERSON, WHICH WE CALL A
CERTIFICATION OF NON-FOREIGN STATUS, IS IMPORTANT. Whether or not you plan to
vote on the merger of each partnership in which you own an interest, please take
the time to complete and return to us the enclosed certification of non-foreign
status. If we receive a properly completed certification of non-foreign status
from you, we will not withhold federal income taxes on the Pioneer Parent common
stock to be issued to you upon the merger of each partnership in which you own
an interest.



     If we, on behalf of a partnership, are required to withhold federal income
taxes from the Pioneer Parent common stock to be issued to you upon the merger
of each partnership in which you own an interest, we will be entitled to deduct
and withhold such taxes from the Pioneer Parent common stock otherwise payable
to you. If amounts are withheld, we may, in our sole discretion:



o    sell any Pioneer Parent common stock withheld from you and use the sale
     proceeds to pay the required withholding taxes;



o    hold any Pioneer Parent common stock withheld from you as security until
     you satisfy the required withholding taxes, at which time the withheld
     Pioneer Parent common stock will be released to you; or



o    take such other reasonable action, at your expense, as is required or
     appropriate to satisfy the required withholding taxes.



Any amounts withheld as described above shall be treated as having been paid to
you.


                            RECORD DATE; VOTING POWER

     You may vote at the special meeting for each partnership in which you own
an interest if you owned partnership interests as of the close of business on ,
2001. We call this date the record date. For each partnership in which you own a
partnership interest, you may cast one vote representing your percentage of
partnership interests in that partnership. The percentage of partnership
interests that you own is determined by comparing the amount of:

o    your, or your predecessor's, initial investment, including any additional
     assessments, in the partnership; to

o    the total investment of all partners, including any additional assessments,
     in the partnership.

     YOUR VOTE IS IMPORTANT. Whether or not you plan to attend the special
meeting for each partnership in which you own an interest, please take the time
to vote by completing and mailing to us the enclosed proxy card. This will not
prevent you from revoking your proxy at any time prior to the special meeting
for each partnership in which you own an interest or from voting your
partnership interests in person if you later choose to attend the special
meeting for each partnership in which you own an interest.

                  PARTNER VOTE REQUIRED TO APPROVE THE MERGERS

     The favorable vote of the holders of a majority of the limited partnership
interests in a partnership is required to approve the merger proposals for that
partnership, except that Parker & Parsley 91-A, L.P. and Parker & Parsley 91-B,
L.P. each require the favorable vote of the holders, other than Pioneer USA, of
66-2/3% of its limited partnership interests to approve the merger proposals.


     We are generally entitled under the partnership agreements to vote
partnership interests we hold as limited partners at the special meeting for
each partnership in which we hold an interest. See "The Special Meetings --
Record Date; Voting Rights and Proxies" on page 58 of this document. We plan to
vote all our partnership interests for the merger proposals. The voting interest
that we hold in each partnership is found in Table 6 of Appendix A.



     Except as set forth above and in "Ownership of Partnership Interests" on
page 64 of this document, none of Pioneer Parent, Pioneer USA, or, to the
knowledge of Pioneer USA, any of their directors or executive officers, or any
associate or subsidiary of Pioneer Parent, Pioneer USA or any such director or
officer, beneficially owns any partnership interests of any partnership or is
otherwise entitled to vote any partnership interests.


     If limited partners of a partnership approve the merger agreement, but do
not approve the merger amendment, or vice versa, the partnership will not be
able to merge. LIMITED PARTNERS WHO WANT THEIR PARTNERSHIP TO PARTICIPATE IN THE
MERGER SHOULD VOTE FOR EACH OF THE MERGER PROPOSALS.


                            CONDITIONS TO EACH MERGER
                                  (SEE PAGE 55)


     We will complete the merger of each partnership only if the conditions of
the merger agreement are satisfied or, if permitted, waived. These conditions
include:


                                      -9-
   20


o    the limited partners' adoption and approval of the merger proposals;

o    the absence of any law or court order that prohibits the merger; and

o    the absence of any lawsuit challenging the legality or any aspect of the
     merger.


     So long as the law allows us to do so, Pioneer Parent and we may choose to
complete a merger of any partnership even though a condition has not been
satisfied if the limited partners have approved the merger proposals. Pioneer
Parent and we may complete the merger of any one or some of the partnerships for
which the listed conditions have been satisfied, even if limited partners in
other partnerships do not approve the merger proposals.



                   TERMINATION OF THE MERGER OF A PARTNERSHIP
                                  (SEE PAGE 56)



     Pioneer Parent and Pioneer USA may jointly terminate the merger agreement,
for any or all of the partnerships, at any time, even after limited partner
approval. Either Pioneer Parent or Pioneer USA may terminate the merger
agreement for any or all of the partnerships in some circumstances, including
the following:


o    the limited partners of a partnership fail to approve that partnership's
     merger; or

o    if any of the other parties is in material breach of the merger agreement.


In addition, (1) Pioneer USA may terminate the merger agreement for any
partnership, if Pioneer USA determines that termination of the merger agreement
is required for its board of directors to comply with its fiduciary duties and
(2) Pioneer Parent may abandon the proposed merger of any or all of the
partnerships at any time prior to the special meeting for any such partnership
for any reason including changes in, among other things, the price of Pioneer
Parent common stock, the market prices for oil and gas generally or the oil and
gas industry generally.



                   EFFECT OF DEBT OWED BY A LIMITED PARTNER TO
                            PIONEER USA ON AMOUNT OF
                   PIONEER PARENT COMMON STOCK TO BE RECEIVED
                             BY THE LIMITED PARTNER



     If a limited partner is indebted to Pioneer USA for any portion of the
limited partner's original investment in the partnership, Pioneer USA plans to
apply the Pioneer Parent common stock that would otherwise be distributed to the
limited partner upon completion of the merger of the partnership against that
limited partner's indebtedness. If a limited partner's indebtedness to Pioneer
USA is less than the merger value allocated to limited partnership interests
held by the limited partner, the limited partner will receive Pioneer Parent
common stock equal to the amount by which such merger value exceeds such
indebtedness. If a limited partner's indebtedness to Pioneer USA is greater than
the merger value allocated to the limited partnership interests held by the
limited partner, Pioneer USA may collect the deficiency from the limited
partner.


                     EFFECTS OF THE MERGER OF A PARTNERSHIP
                     ON ITS LIMITED PARTNERS WHO DO NOT VOTE
                             IN FAVOR OF THE MERGER


     You will be bound by the merger of a partnership in which you own interests
if the limited partners in your partnership vote a majority, or 66-2/3% for
Parker & Parsley 91-A, L.P. and Parker & Parsley 91-B, L.P., of their
partnership interests in favor of the merger, even if you vote against the
merger. If the merger of your partnership occurs, you will be entitled to
receive only an amount of Pioneer Parent common stock based on the merger value
for your partnership interests. You will not have appraisal, dissenters' or
similar rights in connection with the merger, even if you vote against the
merger.



                      FUTURE OF A PARTNERSHIP THAT DOES NOT
                            PARTICIPATE IN THE MERGER
                                  (SEE PAGE 51)



     If your partnership does not participate in the merger of that partnership
for any reason, that partnership will remain in existence. Some reasons your
partnership might not participate in the merger are (1) that the limited
partners vote against the merger, (2) that a condition in the merger agreement
is not satisfied, or (3) that Pioneer Parent or we exercise a termination right
with respect to the merger for that partnership.



     At about the same time that we mail certificates representing shares of
Pioneer Parent common stock to the partners of each participating partnership in
payment of the merger value for that partnership, we will mail any cash
distributions that were delayed for administrative purposes prior to the
completion of the merger of each participating partnership to the partners of
each nonparticipating partnership.


     We have not formulated an alternative business plan for any
nonparticipating partnership. The business objectives of each nonparticipating
partnership will continue as they are. We plan to continue to manage each
nonparticipating partnership and operate it in accordance with the terms of its
current partnership agreement. Each nonparticipating partnership will continue
to operate as a separate legal entity with its own assets and liabilities.
Distributions from any nonparticipating partnership are expected to continue to
decline since its production revenues are expected to continue to decline more
quickly than its production costs. Regardless of whether any nonparticipating
partnership distributes cash, limited partners must continue to include their
share of partnership income and loss in their individual tax returns.


     The board of directors of each of Pioneer Parent and Pioneer USA will
decide what, if any, actions Pioneer Parent or Pioneer USA, respectively, will
take regarding any nonparticipating partnership. Potential activities might
include a tender offer for partnership interests of limited partners or a
proposal to acquire



                                      -10-
   21


the assets of, or merge with, one or more of the nonparticipating partnerships.
The proposal may be on terms similar to or different from those of the mergers
described in this document.

                                EXPENSES AND FEES


     The expenses and fees to be incurred in connection with the merger of each
partnership are expected to be approximately $2.0 million in total. Each
participating partnership will pay its pro rata share, based on its reserve
value, of those estimated expenses and fees. Each nonparticipating partnership
will pay a portion of the estimated expenses and fees of the mergers otherwise
allocable to the partnership based on a fraction, the numerator of which is the
percentage of the partnership's limited partnership interests that are voted in
favor of the merger proposals and the denominator of which is the percentage of
the partnership's limited partnership interests for which votes are cast.
Pioneer Parent has agreed to pay (1) the remainder of the estimated expenses and
fees otherwise allocable to such nonparticipating partnership, (2) any expenses
and fees actually incurred in excess of $2.0 million, and (3) if Pioneer Parent
terminates or abandons the merger as to any partnership, any expenses or fees
allocated to that partnership. Pioneer Parent and Pioneer USA have reduced each
partnership's merger value by that partnership's pro rata share of the estimated
expenses and fees.


                               REGULATORY APPROVAL


     No federal or state regulatory requirements must be satisfied or approvals
obtained in connection with the merger of any of the partnerships as described
in this document, except (1) filing a registration statement that includes this
document with the SEC and obtaining the SEC's declaration that the registration
statement is effective under the Securities Act of 1933, and (2) filing
certificates of merger with the Secretary of State of the State of Delaware and
the Secretary of the State of the State of Texas.


                              SIMILAR TRANSACTIONS


     During March 2001, Pioneer Parent offered to acquire all of the direct oil
and gas interests owned by some former officers and employees of Pioneer Parent
and Pioneer USA in properties in which Pioneer Parent and Pioneer USA own
interests. The merger value for the direct oil and gas interests was equal to
the present value of estimated future net revenues from the oil and gas reserves
attributable to the interests, as of March 31, 2001. In determining the present
value, Pioneer Parent and Pioneer USA used (1) a five-year NYMEX futures price
for oil and gas as of March 19, 2001 with prices held constant after year five
at the year five price, less standard industry adjustments, (2) historical
operating costs adjusted only for those items affected by commodity prices, such
as production taxes and ad valorem taxes, and (3) a 13.5% discount rate. The
consideration offered in the purchases of the direct oil and gas interests was
all cash since offering and registering Pioneer Parent common stock in those
purchases was cost-prohibitive due to the small size of such transactions.



     Additionally, in December 2000, Pioneer Parent received the approval of the
partners of 13 employee limited partnerships to merge with Pioneer USA for total
merger consideration of $2.0 million. Of the total merger consideration, $0.3
million was paid to current Pioneer Parent employees. The merger value of each
employee partnership was equal to the sum of the present value of estimated
future net revenues from the partnership's estimated oil and gas reserves and
its net working capital, in each case as of September 30, 2000, less the cash
distributions on October 15, 2000 and November 15, 2000, by that partnership to
its partners. In determining the present value, Pioneer Parent and Pioneer USA
used (1) a five-year NYMEX futures price for oil and gas as of August 25, 2000
with prices held constant after year five at the year five price, less standard
industry adjustments, (2) historical operating costs adjusted only for those
items affected by commodity prices, such as production taxes and ad valorem
taxes, and (3) a 13.5% discount rate. The consideration paid in the mergers of
the employee limited partnerships was all cash. Using the same parameters as
described above, Pioneer Parent purchased all of the direct oil and gas
interests held by Scott D. Sheffield, its chairman of the board of directors and
chief executive officer, for $0.2 million during October 2000. As with the
purchases of the direct oil and gas interests described above, offering and
registering Pioneer Parent common stock in those mergers was cost-prohibitive
due to the small size of such transactions.



                               THIRD PARTY OFFERS
                                  (SEE PAGE 52)



     We will consider any offers from third parties to purchase any partnership
or its assets. Those who wish to make an offer for any partnership or its assets
must demonstrate to our reasonable satisfaction their financial ability and
willingness to complete such a transaction. Before reviewing non-public
information about a partnership, a third party will need to enter into a
customary confidentiality agreement. Offers should be at prices and on terms
that are fair to the partners of the partnership and more favorable to the
unaffiliated limited partners than the prices and terms proposed in the merger
for that partnership described in this document. Pioneer Parent has the right to
match or top any such offer. In addition, any such offer would be subject to our
right to continue operation of the properties. Since first announcing our
willingness to consider third party offers in September 1999, we have not
received any third party offer for any partnership or its assets.



                       COMPARATIVE PER SHARE MARKET PRICE
                            INFORMATION (SEE PAGE 62)



     On April 16, 2001, the last full trading day before the public announcement
of the proposed merger of each partnership, Pioneer Parent common stock closed
at $17.27 per share. On        , 2001, Pioneer Parent common stock closed at
$   per share.


     No liquid market exists for interests in any of the partnerships. See Table
15 of Appendix A for historical information about recent trades per $1,000


                                      -11-
   22


initial limited partner investment in each partnership and Table 7 of Appendix A
for the average historical quarterly cash distributions per $1,000 initial
limited partner investment for each partnership.


                                      -12-
   23


        SUMMARY HISTORICAL CONSOLIDATED FINANCIAL DATA OF PIONEER PARENT


     The following table sets forth summary financial information of Pioneer
Parent for the three months ended March 31, 2001 and 2000 and each of the five
years in the period ended December 31, 2000. This financial information was
derived from the consolidated financial statements of Pioneer Parent. This data
should be read in conjunction with the consolidated financial statements of
Pioneer Parent and Management's Discussion and Analysis of Financial Condition
and Results of Operations contained in the reports incorporated by reference in
this document.





                                            THREE MONTHS ENDED
                                                 MARCH 31,                              YEAR ENDED DECEMBER 31,
                                           ----------------------    -------------------------------------------------------------
                                              2001        2000          2000         1999         1998        1997(a)       1996
                                           ---------    ---------    ---------    ---------    ---------    ---------    ---------
                                                 (UNAUDITED)
                                                                   (IN MILLIONS EXCEPT PER SHARE DATA)
                                                                                                  
STATEMENT OF OPERATIONS DATA:
  Revenues:
   Oil and gas ........................... $   258.0    $   174.4    $   852.7    $   644.6    $   711.5    $   536.8    $   396.9
   Natural gas processing ................        --           --           --           --           --           --         23.8
   Interest and other (b) ................       5.1          3.7         25.8         89.7         10.4          4.3         17.5
   Gain (loss) on disposition of
    assets, net ..........................       7.3          8.4         34.2        (24.2)         (.4)         4.9         97.1
                                           ---------    ---------    ---------    ---------    ---------    ---------    ---------
                                               270.4        186.5        912.7        710.1        721.5        546.0        535.3
                                           ---------    ---------    ---------    ---------    ---------    ---------    ---------
  Costs and expenses:
   Oil and gas production ................      55.8         43.1        189.3        159.5        223.5        144.2        110.3
   Natural gas processing ................        --           --           --           --           --           --         12.5
   Depletion, depreciation and
    amortization .........................      52.2         51.9        214.9        236.1        337.3        212.4        112.1
   Impairment of properties and
    facilities ...........................        --           --           --         17.9        459.5      1,356.4           --
   Exploration and abandonments ..........      22.9         13.1         87.5         66.0        121.9         77.2         23.0
   General and administrative ............      10.4          9.7         33.3         40.2         73.0         48.8         28.4
   Reorganization ........................        --           --           --          8.5         33.2           --           --
   Interest ..............................      35.6         39.8        162.0        170.3        164.3         77.5         46.2
   Other(c) ..............................      25.2         14.4         67.2         34.7         39.6          7.1          2.5
                                           ---------    ---------    ---------    ---------    ---------    ---------    ---------
                                               202.1        172.0        754.2        733.2      1,452.3      1,923.6        335.0
                                           ---------    ---------    ---------    ---------    ---------    ---------    ---------
  Income (loss) before income taxes
   and extraordinary item ................      68.3         14.5        158.5        (23.1)      (730.8)    (1,377.6)       200.3
  Income tax benefit (provision) .........       (.4)          .3          6.0           .6        (15.6)       500.3        (60.1)
                                           ---------    ---------    ---------    ---------    ---------    ---------    ---------
  Income (loss) before extraordinary
   item ..................................      67.9         14.8        164.5        (22.5)      (746.4)      (877.3)       140.2
  Extraordinary item .....................        --           --        (12.3)          --           --        (13.4)          --
                                           ---------    ---------    ---------    ---------    ---------    ---------    ---------
  Net income (loss) ...................... $    67.9    $    14.8    $   152.2    $   (22.5)   $  (746.4)   $  (890.7)   $   140.2
                                           =========    =========    =========    =========    =========    =========    =========
  Income (loss) before extraordinary
   item per share:
    Basic ................................ $     .69    $     .15    $    1.65    $    (.22)   $   (7.46)   $  (16.88)   $    3.95
                                           =========    =========    =========    =========    =========    =========    =========
    Diluted .............................. $     .68    $     .15    $    1.65    $    (.22)   $   (7.46)   $  (16.88)   $    3.47
                                           =========    =========    =========    =========    =========    =========    =========
  Net income (loss) per share:
    Basic ................................ $     .69    $     .15    $    1.53    $    (.22)   $   (7.46)   $  (17.14)   $    3.95
                                           =========    =========    =========    =========    =========    =========    =========
    Diluted .............................. $     .68    $     .15    $    1.53    $    (.22)   $   (7.46)   $  (17.14)   $    3.47
                                           =========    =========    =========    =========    =========    =========    =========
  Dividends per share ....................        --    $      --    $      --    $      --    $     .10    $     .10    $     .10
                                           =========    =========    =========    =========    =========    =========    =========
  Weighted average basic shares
   outstanding ...........................      98.4        100.2         99.4        100.3        100.1         52.0         35.5


STATEMENT OF CASH FLOWS DATA:
  Cash flows from operating activities ... $   131.7    $    47.2    $   430.1    $   255.2    $   314.1    $   228.2    $   230.1
  Cash flows from (used in) investing
     activities .......................... $   (88.8)   $   (39.9)   $  (194.5)   $   199.0    $  (517.0)   $  (341.2)   $    13.7
  Cash flows from (used in) financing
     activities .......................... $   (50.5)   $    (8.9)   $  (244.1)   $  (479.1)   $   190.9    $   166.0    $  (245.4)

BALANCE SHEET DATA (AS OF DECEMBER 31):
  Working capital (deficit)(d) ........... $  (153.1)   $     3.1    $   (25.1)   $   (13.7)   $  (324.8)   $    46.6    $    26.1
  Property, plant and equipment, net ..... $ 2,557.1    $ 2,511.3    $ 2,515.0    $ 2,503.0    $ 3,034.1    $ 3,515.8    $ 1,040.4
  Total assets ........................... $ 2,922.2    $ 2,969.9    $ 2,954.4    $ 2,929.5    $ 3,481.3    $ 4,153.0    $ 1,199.9
  Long-term obligations .................. $ 1,744.8    $ 1,913.8    $ 1,804.5    $ 1,914.5    $ 2,101.2    $ 2,124.0    $   329.0
  Preferred stock of subsidiary .......... $      --    $      --    $      --    $      --    $      --    $      --    $   188.8
  Total stockholders' equity(e) .......... $   841.0    $   816.6    $   904.9    $   774.6    $   789.1    $ 1,548.8    $   530.3



                                      -13-
   24


----------

(a)  Includes amounts relating to the acquisition of MESA Inc. and Chauvco
     Resources Ltd. in August and December 1997, respectively.

(b)  1999 includes $41.8 million of option fees and liquidated damages related
     to an unsuccessful asset sale and $30.2 million of income associated with
     an excise tax refund.


(c)  The three month periods ended March 31, 2001 and 2000 and the years ended
     December 31, 2000, 1999, 1998 and 1997 include non-cash mark-to-market
     charges for changes in the fair values of non-hedge financial instruments
     of $8.8 million, $13.5 million, $58.5 million, $27.0 million, $21.2 million
     and $5.2 million, respectively.



(d)  The working capital deficit for the three month period ended March 31, 2001
     included $101.5 million of net derivative obligations. The 1998 working
     capital deficit includes $306.5 million of current maturities of long-term
     debt.



(e)  On January 1, 2001, Pioneer Parent adopted the provisions of Statement of
     Financial Accounting Standards No. 133, "Accounting for Derivative
     Instruments and Hedging Activities." In accordance with those provisions,
     Pioneer Parent recognized a transition adjustment which significantly
     reduced stockholders' equity. As of March 31, 2001, deferred hedge gains
     and losses have reduced Pioneer Parent's stockholders' equity by $110.5
     million.




                                      -14-
   25


      SUMMARY UNAUDITED PRO FORMA COMBINED FINANCIAL DATA OF PIONEER PARENT



     The following table sets forth summary unaudited pro forma combined
financial data of Pioneer Parent that is presented to give effect to the merger
of each of the partnerships. The information was prepared based on the following
assumptions:


     o    The merger of each partnership will be accounted for as a purchase
          business combination under generally accepted accounting principles.

     o    The income statement data is presented as if the merger of each
          partnership had been consummated on January 1, 2000.


     o    The balance sheet data is presented as if the merger of each
          partnership had been consummated on March 31, 2001.


     You should consider the following:


     o    The unaudited pro forma combined financial data are not necessarily
          indicative of the results of operations or the financial position of
          Pioneer Parent that would have occurred had the merger of each
          partnership in which you own an interest been consummated on January
          1, 2000, nor are they necessarily indicative of future results of
          operations or financial position of Pioneer Parent.



     o    The unaudited pro forma combined revenue and expense data exclude the
          cost savings expected to be realized through the consolidation of
          operations of Pioneer Parent and each partnership and the elimination
          of duplicate expenses.



     The unaudited pro forma combined financial statements should be read
together with (1) the historical consolidated financial statements of Pioneer
Parent incorporated by reference in this document, (2) the historical financial
statements of each partnership contained in the supplement to this document for
the partnership, and (3) the unaudited pro forma combined financial statements
contained elsewhere in this document. With respect to future cash distributions,
see "Questions and Answers About the Merger of Each Partnership -- What Happens
to My Future Cash Distributions?" See also "Where You Can Find More Information"
on the inside front cover page of this document.





                                                                             PRO FORMA           PRO FORMA
                                                                         THREE MONTHS ENDED      YEAR ENDED
                                                                           MARCH 31, 2001    DECEMBER 31, 2000
                                                                           --------------    -----------------
                                                                         (IN THOUSANDS EXCEPT PER SHARE DATA)
                                                                                        
STATEMENTS OF OPERATIONS:
     Revenues:
         Oil and gas ..............................................        $   270,754         $   901,382
         Interest and other .......................................              5,261              26,231
         Gain on disposition of assets, net .......................              7,368              34,425
                                                                           -----------         -----------
                                                                               283,383             962,038
                                                                           -----------         -----------
     Costs and Expenses:
         Oil and gas production ...................................             59,533             202,176
         Depletion, depreciation and amortization .................             53,754             221,942
         Exploration and abandonments .............................             22,924              87,619
         General and administrative ...............................             12,282              40,406
         Interest .................................................             35,616             161,952
         Other ....................................................             25,217              67,231
                                                                           -----------         -----------
                                                                               209,326             781,326
                                                                           -----------         -----------
     Income from continuing operations before income taxes ........             74,057             180,712
     Income tax benefit (provision) ...............................               (400)              6,000
                                                                           -----------         -----------
     Income from continuing operations ............................        $    73,657         $   186,712
                                                                           ===========         ===========
     Income from continuing operations per common share, basic ....        $       .71         $      1.77
     Income from continuing operations per common share,
         diluted ..................................................        $       .70         $      1.77
     Weighted average number of shares outstanding, basic .........            104,235             105,234
     Weighted average number of shares outstanding, diluted .......            105,564             105,618
BALANCE SHEET DATA (AT PERIOD END)
     Property, plant and equipment, net ...........................        $ 2,658,004
     Total assets .................................................        $ 3,029,547
     Long-term debt ...............................................        $ 1,550,230
     Stockholders' equity .........................................        $   946,376




                                      -15-
   26


                     SUMMARY OIL AND GAS RESERVE INFORMATION


     The following table sets forth summary information on Pioneer Parent's and
the combined partnerships' proved oil and gas reserves at December 31, 2000, and
the summary pro forma combined information of Pioneer Parent on proved oil and
gas reserves assuming the merger of each partnership had taken place on December
31, 2000. Pioneer Parent's and the combined partnerships' historical and Pioneer
Parent's pro forma combined proved oil and gas reserve information set forth
below and incorporated by reference in this document are only estimates based
primarily on reports prepared by Pioneer Parent's engineers for Pioneer Parent's
proved reserves and independent petroleum engineers for the combined
partnerships' proved reserves as of December 31, 2000. The reserve information
as of December 31, 2000 is based on the prices of oil and gas as of that time.
The discounted future net cash flows set forth or incorporated by reference in
this document should not be considered as the current market value of the
estimated oil and gas reserves attributable to Pioneer Parent's, the combined
partnerships' or any partnership's properties. Under the applicable requirements
of the Securities and Exchange Commission, the estimated discounted future net
cash flows from proved reserves are based on prices and costs as of the date of
the estimate, while actual future prices and costs may be materially higher or
lower.


        SUMMARY HISTORICAL AND PRO FORMA OIL AND GAS RESERVE INFORMATION
                              AT DECEMBER 31, 2000




                                                                        OIL AND       NATURAL    BARRELS OF
                                                                          NGLS          GAS      EQUIVALENTS
                                                                        (MMBbls)       (Bcf)       (MMBOE)
                                                                        ---------    ---------   ----------
                                                                                         
NET PROVED RESERVES (HISTORICAL):
PIONEER PARENT:
   Developed .......................................................        232.5      1,507.8        483.8
   Undeveloped .....................................................         79.8        387.7        144.4
                                                                        ---------    ---------    ---------
     Total .........................................................        312.3      1,895.5        628.2
                                                                        =========    =========    =========
COMBINED PARTNERSHIPS:
   Developed .......................................................         27.3         37.6         33.6
                                                                        =========    =========    =========

NET PROVED RESERVES (PRO FORMA COMBINED):
   Developed .......................................................        261.8      1,546.8        519.6
   Undeveloped .....................................................         79.8        387.7        144.4
                                                                        ---------    ---------    ---------
     Total .........................................................        341.6      1,934.5        664.0
                                                                        =========    =========    =========

RESERVE VALUATION INFORMATION (IN MILLIONS):
PIONEER PARENT:
   Estimated future net cash flows .................................                              $  10,864
   Standardized measure of discounted future net cash flows ........                              $   5,646
COMBINED PARTNERSHIPS:
   Estimated future net cash flows .................................                              $     423
   Standardized measure of discounted future net cash flows(1) .....                              $     207
PRO FORMA COMBINED:
   Estimated future net cash flows .................................                              $  11,267
   Standardized measure of discounted future net cash flows ........                              $   5,838



---------

(1)  The combined partnerships do not reflect a federal income tax provision
     since the partners of each partnership include the income of the
     partnership in their respective individual federal income tax returns.


                                      -16-
   27

                           COMPARATIVE PER SHARE DATA


     The following table summarizes the per share information for Pioneer Parent
and the per $1,000 limited partner investment for the combined partnerships on a
historical, equivalent pro forma combined and pro forma combined basis. The pro
forma information gives effect to the merger of each partnership accounted for
by Pioneer Parent as a purchase business combination. You should read this
information together with the historical financial statements (1) included in
the annual reports on Form 10-K and other information that Pioneer Parent has
filed with the Securities and Exchange Commission and (2) included in the
supplement to this document for each partnership. See "Where You Can Find More
Information" on the inside front cover page of this document. With respect to
future cash distributions, see "Questions and Answers About the Merger of Each
Partnership -- What Happens to My Future Cash Distributions?" and "Risk Factors
-- Pioneer Parent Might Not Declare Dividends." You should not rely on the pro
forma combined information as being indicative of the results that would have
occurred had the merger of each partnership been completed on January 1, 2000,
or the future results that Pioneer Parent will experience after the merger of
each partnership. In addition, because Pioneer Parent has both a different legal
structure and purpose from each partnership, the information about Pioneer
Parent and the information about the combined partnerships are not necessarily
comparable.





                                                                            THREE MONTHS ENDED       YEAR ENDED
                                                                              MARCH 31, 2001      DECEMBER 31, 2000
                                                                            ------------------    -----------------
                                                                                            
HISTORICAL -- PIONEER PARENT:
     Income from continuing operations per share:
         Basic ...........................................................        $   .69              $  1.65
         Diluted .........................................................            .68                 1.65
     Book value per share ................................................           8.56                 9.19
     Cash dividends per common share .....................................           0.00                 0.00
HISTORICAL -- COMBINED PARTNERSHIPS:
     Income per $1,000 limited partner investment ........................        $ 14.84              $ 55.15
     Book value per $1,000 limited partner investment ....................         120.50               124.45
     Cash distributions per $1,000 limited partner investment ............          18.79                57.22
EQUIVALENT PRO FORMA COMBINED PARTNERSHIPS PER $1,000 LIMITED PARTNER
INVESTMENT ON AN EQUIVALENT PER SHARE BASIS(1):
     Income per $1,000 limited partner investment:
         Basic ...........................................................        $  9.02              $ 22.50
         Diluted .........................................................           8.90                22.50
     Book value per $1,000 limited partner investment ....................         115.53
PRO FORMA COMBINED -- PIONEER PARENT:
     Income from continuing operations per share:
         Basic ...........................................................        $   .71              $  1.77
         Diluted .........................................................            .70                 1.77
     Book value per share ................................................           9.09




---------
(1)  Represents the "Historical -- Combined Partnerships" amounts multiplied by
     12.71, which represents the weighted average number shares of Pioneer
     Parent common stock to be received per $1,000 limited partner investment.




                                      -17-
   28
                                  RISK FACTORS

     You should carefully consider the following risk factors in determining
whether to vote to approve the merger proposals for each partnership in which
you own interests.

             RISK FACTORS RELATING TO THE MERGER OF EACH PARTNERSHIP


THE MERGER VALUE FOR EACH PARTNERSHIP INVOLVES ESTIMATES THAT MAY VARY
MATERIALLY FROM THE QUANTITIES OF OIL AND GAS ACTUALLY RECOVERED, AND
CONSEQUENTLY FUTURE NET REVENUES



     The calculations of each partnership's estimated reserves of crude oil,
natural gas liquids and natural gas and future net revenues from those reserves
included in this document are only estimates. Actual prices, production,
operating expenses and quantities of recoverable oil and natural gas reserves
may vary from those assumed in the estimates. Any significant variance from the
assumptions used could result in the actual quantity of each partnership's
reserves and future net revenues being materially different from the estimates
used in the calculation of the merger value for that partnership.



THE MERGER VALUE FOR A PARTNERSHIP WILL NOT BE ADJUSTED FOR CHANGES IN OIL AND
GAS PRICES BEFORE THE COMPLETION OF ITS MERGER



     The merger value for each partnership in which you own an interest
determines the amount of Pioneer Parent common stock you will receive in the
merger of that partnership. The merger value for each partnership is equal to
the sum of the present value of estimated future net revenues from the
partnership's estimated oil and gas reserves and its net working capital, in
each case as of March 31, 2001, less its pro rata share, based on its reserve
value, of the estimated expenses and fees of the mergers of all of the
partnerships and less the cash distribution to be mailed on or about July 12,
2001, by the partnership to its partners. Although oil and gas prices have
fluctuated greatly in the recent past and may continue to do so, the merger
value for a partnership will not be adjusted as of the closing date of the
merger of that partnership to reflect any general changes in oil or gas prices,
or any other matter generally affecting the oil and gas industry, occurring
after March 31, 2001 and prior to the closing date of the merger.


THE NUMBER OF SHARES OF PIONEER PARENT COMMON STOCK THE LIMITED PARTNERS OF EACH
PARTNERSHIP WILL RECEIVE MAY DECREASE BETWEEN NOW AND THE COMPLETION OF THE
MERGER OF THE PARTNERSHIP


     The number of shares of Pioneer Parent common stock to be issued to the
limited partners of each partnership upon the merger of the partnership will be
determined by dividing the merger value assigned to the partnership by the value
of one share of Pioneer Parent common stock determined as described below. As
discussed above, the merger value for each partnership will not be changed
between now and the completion of the merger for the partnership. In addition,
for purposes of example in this document, a share of Pioneer Parent common stock
has been valued at an assumed average closing price of $18.00. However, the
value of a share of Pioneer Parent common stock will be recalculated by
computing the average closing price of the Pioneer Parent common stock, as
reported by the New York Stock Exchange, for the ten trading days ending three
business days before the initial date of the special meeting for each
partnership. This recalculated value, and not the assumed closing average
closing price of $18.00 per share of Pioneer Parent common stock used for
illustration purposes in this document and on each limited partner's proxy card,
will be used to determine the actual number of shares of Pioneer Parent common
stock to be issued in the merger of each partnership. The recalculated value may
be more or less than the assumed average closing price of $18.00 per share of
Pioneer Parent common stock. If it is more than $18.00, you will receive fewer
shares of Pioneer Parent common stock than the illustrations in this document
show. For historical and current market prices of Pioneer Parent common stock,
see "Comparative Per Share Market Price and Dividend Information" on page 62.


CURRENT MARKET PRICES FOR OIL AND GAS MAY BE HIGHER THAN THE MERGER VALUE FOR A
PARTNERSHIP, WHICH MAY AFFECT DELIVERABILITY OF THE FAIRNESS OPINION


     Oil and gas prices have fluctuated greatly in the recent past and may
continue to do so in the future. Pioneer Parent calculated each merger value
based on oil and gas prices that it believes to be fair and that are supported
by current market prices. Changes in current oil and gas prices may affect the
ability of Pioneer to obtain an opinion at the time this document is mailed to
the limited partners of each partnership as to the fairness of the consideration
to be received by limited partners. If the prices used in the calculation of
each merger value significantly differ from current prices and if Pioneer Parent
does not modify its offer, the fairness opinion provider may be unable to render
its opinion.


YOU WERE NOT INDEPENDENTLY REPRESENTED IN ESTABLISHING THE TERMS OF THE MERGER
OF EACH PARTNERSHIP


     Pioneer Parent and Pioneer USA determined the terms of the merger of each
partnership, including the method for determining the merger value for that
partnership, and the type and allocation among the partners of the



                                      -18-
   29



consideration to be given in exchange for partnership interests. We did not seek
recommendations about the type of transaction or the terms or prices from any
independent underwriter, financial advisor or other securities professional
prior to accepting the consideration Pioneer Parent offered. The only
independent representatives in the mergers were Sayles, Lidji & Werbner, A
Professional Corporation, which provided legal services to Pioneer USA's board
of directors, Robert A. Stanger & Co., Inc., which will render its fairness
opinion to Pioneer USA's board of directors, and , which will render the legal
opinion required under the partnership agreement for each partnership, other
than Parker & Parsley Producing Properties 88-A, L.P. No representative group of
limited partners and no outside experts or consultants, such as investment
bankers, legal counsel, accountants or financial experts, were engaged solely to
represent the independent interests of the limited partners of any partnership
in structuring and negotiating the terms of the merger for the partnership. If
you had been separately represented, the terms of the merger for a partnership
in which you own interests might have been different and possibly more favorable
to you.



THE INTERESTS OF PIONEER PARENT, PIONEER USA AND THEIR DIRECTORS AND OFFICERS
MAY DIFFER FROM YOUR INTERESTS



     The interests of Pioneer Parent, Pioneer USA, and their directors and
officers may differ from your interests as a result of the relationships among
them. For example, Pioneer USA, as general or managing partner of each
partnership, has a duty to manage the partnership in the best interests of the
limited partners. Additionally, Pioneer USA has a duty to operate its business
for the benefit of its sole stockholder, Pioneer Parent. Also, the members of
Pioneer USA's board of directors have duties to both the limited partners of
each partnership and to Pioneer Parent. All of the members of Pioneer USA's
board of directors are officers of Pioneer Parent and have duties to Pioneer
Parent's stockholders. Pioneer USA's board of directors was aware of these
interests and considered them in approving the merger proposals for each
partnership. See "Interests of Pioneer Parent, Pioneer USA and Their Directors
and Officers" on page 63 of this document.



IT IS UNCLEAR WHAT THE MARKET DEMAND IS FOR ANY PARTNERSHIP OR ITS ASSETS OR
THAT THE TERMS OF THE MERGER OF EACH PARTNERSHIP ARE AS FAVORABLE AS COULD BE
OBTAINED IN A THIRD PARTY SALE


     In September 1999, we first announced our willingness to consider third
party offers to purchase any partnership or its assets at prices that are higher
than the 1999 merger value for the partnership, but subject to our right to
continue operation of the properties. We believe this limited form of auction
would result in a better price to the limited partners of each partnership than
if we merely offered the partnership or its assets for sale at any price. Since
that time, we have not received any third party offer for any partnership or its
assets. As a result, we cannot be sure what the market demand is for any
partnership or its assets, individually or as a whole with the other
partnerships, or what a third party would offer for any partnership. Also,
although we do not have any plans to sell or relinquish our operating rights in
any third party sale, we cannot be sure what the market demand is for any
partnership or its assets if we also sold or relinquished our operating rights.
No assurance may be given that the terms of the merger of each partnership are
as favorable as could be obtained from a sale of any partnership or its assets,
individually or as a whole with the other partnerships, to an unrelated party.


POTENTIAL LITIGATION CHALLENGING THE MERGER OF A PARTNERSHIP MAY DELAY OR BLOCK
THE MERGER AND, AS A RESULT, YOUR RECEIPT OF THE PIONEER PARENT COMMON STOCK



     One or more of the partners opposed to the merger of a partnership in which
such partner or partners own an interest may initiate legal action to stop the
merger of the partnership or to seek damages for alleged violations of federal
and state laws. Litigation challenging the merger of any partnership may delay
or block the closing of the merger for one or more of the partnerships. In
addition, if any lawsuits are filed, Pioneer Parent or Pioneer USA may decide to
terminate one or more of the mergers. If the merger of a partnership in which
you own an interest is delayed, blocked or terminated, we will delay or
terminate the issuance of the Pioneer Parent common stock that you would
otherwise receive.



REPURCHASE OFFERS IN 2001 BY EACH OF THE SIX PARTNERSHIPS WITH A REPURCHASE
OBLIGATION WERE HIGHER THAN THE MERGER VALUE FOR THE PARTNERSHIP


     The limited partners of each of the partnerships listed below may require
us to repurchase their partnership interests for cash at the times and under the
conditions described in the partnership agreements for the partnership:

         Parker & Parsley 82-I, Ltd.
         Parker & Parsley 82-II, Ltd.
         Parker & Parsley 82-III, Ltd.
         Parker & Parsley 83-A, Ltd.
         Parker & Parsley 83-B, Ltd.
         Parker & Parsley 84-A, Ltd.


     The 2001 repurchase offers were commenced and will be completed before the
date of this document. In each of the partnerships with a repurchase obligation,
the repurchase price in 2001 is higher than the price being offered



                                      -19-
   30



in the merger of the partnership. For a list of the repurchase prices in 2001
and the prior two years, see Table 8 of Appendix A. For a description of the
mechanics of the repurchase rights, see "Special Factors - Fairness Opinion -
Repurchase Offers" on page 38.



     In addition, if the limited partners of a partnership with repurchase
rights vote a majority of their partnership interests in favor of the merger of
the partnership, those repurchase rights will terminate on completion of the
merger. As a result, if the oil and gas prices used in calculating the
repurchase prices in the future were high enough to offset the additional
33-1/3% discount factor used in the repurchase calculation, the limited partners
would not have the opportunity to require Pioneer USA to repurchase the limited
partners' partnership interests for a price higher than the merger value for the
partnership.


YOU COULD BE BOUND BY THE MERGER OF EACH PARTNERSHIP IN WHICH YOU OWN AN
INTEREST EVEN IF YOU DO NOT VOTE IN FAVOR OF THE MERGER


     You will be bound by the merger of each partnership in which you own an
interest if the limited partners in the partnership vote a majority, or 66-2/3%
for Parker & Parsley 91-A, L.P. and Parker & Parsley 91-B, L.P., of their
partnership interests in favor of the merger, even if you vote against the
merger or do not vote. If the merger of the partnership occurs, you will be
entitled to receive only an amount of Pioneer Parent common stock based on the
merger value of your partnership interests in the partnership. Under the laws of
the State of Delaware and the State of Texas, which are the states of formation
of the partnerships, you are not entitled to appraisal or dissenters' rights
with respect to the merger of any partnership.



              RISKS ASSOCIATED WITH AN INVESTMENT IN PIONEER PARENT



LIMITED PARTNERS WHO BECOME PIONEER PARENT STOCKHOLDERS WILL OWN STOCK IN A
CORPORATION RATHER THAN A LIMITED PARTNERSHIP INTEREST IN A LIMITED PARTNERSHIP
RESULTING IN A FUNDAMENTAL CHANGE IN THE NATURE OF THEIR INVESTMENTS



     Limited partners of a participating partnership will become stockholders of
Pioneer Parent and will fundamentally change the nature of their investments.
Each partnership, other than Parker & Parsley 81-I, Ltd., Parker & Parsley
81-II, Ltd., Parker & Parsley 82-I, Ltd., Parker & Parsley 82-II, Ltd., Parker &
Parsley 82-III, Ltd., Parker & Parsley 83-A, Ltd., Parker & Parsley 83-B, Ltd.
and Parker & Parsley 84-A, Ltd., was formed as finite-life investment. The
partners of each partnership receive regular cash distributions out of the
partnership's net operating income and special distributions upon liquidation of
the partnership's oil and gas assets. In contrast, Pioneer Parent intends to
operate for an indefinite period of time and has no specific plans for the sale
of its investments. Because Pioneer Parent will spend a portion of its cash flow
on acquisitions, drilling and other activities, the activities of Pioneer Parent
may involve higher levels of risk than those associated with the present or
future operations of each partnership. Instead of having their investments
liquidated through the liquidation of Pioneer Parent's assets, stockholders
should expect to be able to liquidate their investment in Pioneer Parent only
through the sale of their investments in the market. The amount realized through
the sale of shares of Pioneer Parent common stock may not be equal to the amount
that would have been realized by stockholders through the sale of Pioneer
Parent's assets. Stockholders will thus be subject to the market risks of all
public companies, particularly in that the value of their equity securities may
fluctuate from time to time depending upon general market conditions, conditions
in the oil and gas industry, and Pioneer Parent's future performance. For a
description of the differences between the terms of shares of Pioneer Parent
common stock and partnership interests in each partnership, see "Comparison of
Rights of Stockholders and Partners" on page 73.



PIONEER PARENT MIGHT NOT DECLARE DIVIDENDS



     Limited partners of a participating partnership will become stockholders of
Pioneer Parent and will not receive cash distributions or will receive
distributions much smaller than the distributions received from the partnership.
Pioneer Parent's board of directors did not declare dividends to its
stockholders during 1999, 2000 or the three months ended March 31, 2001. The
determination of the amount of future cash dividends, if any, to be declared and
paid is in the sole discretion of Pioneer Parent's board of directors.



LIMITED PARTNERS WHO BECOME PIONEER PARENT STOCKHOLDERS MAY BE DILUTED



     If all partnerships participate in the mergers, the shares of Pioneer
Parent common stock to be issued will represent approximately 4.3% of the shares
of Pioneer Parent common stock outstanding on the date of this document. That
percentage is based upon the number of shares to be issued upon the merger of
each partnership using an assumed average closing price of $18.00 per share of
Pioneer Parent common stock and may increase or decrease depending on the actual
number of shares issued upon the merger of each partnership, which number will
be determined using the actual average closing price of Pioneer Parent common
stock for the ten trading days ending three business days before the initial
date of the special meeting. Because of the increased liquidity afforded to the
limited partners of each partnership after the merger of the partnership, all of
those shares of Pioneer Parent common stock may be offered for sale in a
relatively short period of time, which could result in the price at which shares
of



                                      -20-
   31



Pioneer Parent common stock trade after completion of the merger of each
partnership being less than the price at which such shares traded immediately
prior to the completion of the merger of each partnership. In addition, limited
partners of a partnership who become Pioneer Parent stockholders will be subject
to the risk that their equity interests in Pioneer Parent may be diluted through
the issuance of additional equity securities. Pioneer Parent has the right to
issue, at the discretion of its board of directors, shares other than those to
be issued in the merger of each partnership, upon such terms and conditions and
at such prices as its board of directors may establish. In addition, Pioneer
Parent may in the future issue preferred stock that might have priority over the
Pioneer Parent common stock as to distributions and liquidation proceeds.


DIVIDENDS PAID TO PIONEER PARENT STOCKHOLDERS ARE TAXED AT TWO LEVELS


     Pioneer Parent is taxed on its income, after deduction of expenses, at both
the federal and state levels. Pioneer Parent stockholders, including limited
partners who become Pioneer Parent stockholders, are separately taxed on the
receipt, if any, of dividends.



PIONEER PARENT IS AN INDEPENDENT OIL AND GAS EXPLORATION AND DEVELOPMENT COMPANY
AND ITS BUSINESS ACTIVITIES INVOLVE RISKS



     Pioneer Parent is an independent oil and gas exploration and development
company. Its purpose is to competitively and profitably explore for, develop and
produce proved oil, natural gas liquids and gas reserves. The nature of those
business activities subjects Pioneer Parent to hazards and risks, including the
following:



o    Pioneer Parent's profitability is highly dependent on the prices of oil and
     gas, which have historically been very volatile. Pioneer Parent's revenues,
     profitability, cash flow and future rate of growth are highly dependent on
     prices of oil and gas, which are affected by numerous factors beyond
     Pioneer Parent's control. Oil and gas prices historically have been very
     volatile. If the significant downward trend in oil and gas prices
     experienced in 1998, as compared to 2000 and 1999, were to resume, it would
     have a material adverse effect on Pioneer Parent's revenues, profitability
     and cash flow and could result in a reduction in the carrying value of
     Pioneer Parent's oil and gas properties and an increase in Pioneer Parent's
     deferred tax asset valuation allowance.



o    Pioneer Parent's drilling activities may not be productive. Drilling
     involves numerous risks, including the risk that no commercially productive
     gas or oil reservoirs will be encountered. The cost of drilling, completing
     and operating wells is often uncertain and drilling operations may be
     curtailed, delayed or canceled as a result of a variety of factors,
     including (1) unexpected drilling conditions, (2) pressure or
     irregularities in formations, (3) equipment failures or accidents, (4)
     adverse weather conditions and (5) shortages or delays in the delivery of
     equipment. Pioneer Parent's future drilling activities may not be
     successful and, if unsuccessful, such failure could have an adverse effect
     on Pioneer Parent's future results of operations and financial condition.
     While all drilling, whether developmental or exploratory, involves these
     risks, exploratory drilling involves greater risks of dry holes or failure
     to find commercial quantities of hydrocarbons. Because of the percentage of
     Pioneer Parent's capital budget devoted to exploratory projects, it is
     likely that Pioneer Parent will continue to experience exploration and
     abandonment expense.



o    Pioneer Parent may be required to recognize non-cash charges relating to
     unproved property costs. At December 31, 2000 and 1999, Pioneer Parent
     carried unproved property costs of $229.2 million and $257.6 million,
     respectively. United States generally accepted accounting principles
     require Pioneer Parent to periodically evaluate these costs on a
     project-by-project basis in comparison to their estimated value. These
     evaluations will be affected by (1) results of exploration activities, (2)
     commodity price outlooks, (3) planned future sales or (4) expiration of all
     or a portion of the leases, contracts and permits related to such projects.
     If the quantity of potential reserves determined by such evaluations is not
     sufficient to fully recover the cost invested in each project, Pioneer
     Parent will recognize non-cash charges in the earnings of future periods.
     During 1999 and 1998, Pioneer Parent recognized non-cash impairment
     provisions of $17.9 million and $147.3 million, respectively, to reduce the
     carrying value of its unproved properties.



o    Pioneer Parent's growth depends on its ability to acquire oil and gas
     properties on a profitable basis. Acquisitions of producing oil and gas
     properties have been a key element of Pioneer Parent's growth. Pioneer
     Parent's growth following the full development of its existing property
     base could be impeded if it is unable to acquire additional oil and gas
     properties on a profitable basis. The success of any acquisition will
     depend on a number of factors, including the ability to estimate accurately
     the recoverable volumes of reserves, rates of future production and future
     net revenues attributable to reserves and to assess possible environmental
     liabilities. All of these factors affect whether an acquisition will
     ultimately generate cash flows sufficient to provide a suitable return on
     investment. Even though Pioneer Parent performs a review of the properties
     it seeks to acquire that it believes is consistent with industry practices,
     such reviews are often limited in scope.



                                      -21-
   32


o    If Pioneer Parent is unable to dispose of non-strategic assets at
     acceptable prices this would hinder its ability to make capital resources
     available for more profitable activities. Pioneer Parent regularly reviews
     its property base for the purpose of identifying non-strategic assets, the
     disposition of which would increase capital resources available for other
     activities and create organizational and operational efficiencies. Various
     factors could materially affect the ability of Pioneer Parent to dispose of
     non-strategic assets, including the availability of purchasers willing to
     purchase the non-strategic assets at prices acceptable to Pioneer Parent.



o    The operation of natural gas processing plants involves the potential for
     damage claims. As of December 31, 2000, Pioneer Parent owns interests in
     nine natural gas processing plants and four treating facilities. Pioneer
     Parent operates six of the plants and all four treating facilities. There
     are significant risks associated with the operation of natural gas
     processing plants. Gas and natural gas liquids are volatile and explosive
     and may include carcinogens. Damage to or misoperation of a natural gas
     processing plant or facility could result in an explosion or the discharge
     of toxic gases, which could result in significant damage claims in addition
     to interrupting a revenue source.



o    Pioneer Parent is not fully insured against operating hazards. Pioneer
     Parent's operations are subject to all the risks normally incident to the
     oil and gas exploration and production business, including blowouts,
     cratering, explosions and pollution and other environmental damage, any of
     which could result in substantial losses to Pioneer Parent due to injury or
     loss of life, damage to or destruction of wells, production facilities or
     other property, clean-up responsibilities, regulatory investigations and
     penalties and suspension of operations. Although Pioneer Parent currently
     maintains insurance coverage that it considers reasonable and that is
     similar to that maintained by comparable companies in the oil and gas
     industry, it is not fully insured against certain of these risks, either
     because such insurance is not available or because of high premium costs.



o    In the event of noncompliance, liabilities under environmental laws and
     regulations could be substantial. The oil and gas business is also subject
     to environmental hazards, such as oil spills, gas leaks and ruptures and
     discharges of toxic substances or gases that could expose Pioneer Parent to
     substantial liability due to pollution and other environmental damage. A
     variety of federal, state and foreign laws and regulations govern the
     environmental aspects of the oil and gas business. Noncompliance with these
     laws and regulations may subject Pioneer Parent to penalties, damages or
     other liabilities, and compliance may increase the cost of Pioneer Parent's
     operations. Such laws and regulations may also affect the costs of
     acquisitions.



     Pioneer Parent does not believe that its environmental risks are materially
     different from those of comparable companies in the oil and gas industry.
     Nevertheless, no assurance can be given that future environmental laws will
     not result in a curtailment of production or processing or a material
     increase in the costs of production, development, exploration or processing
     or otherwise adversely affect Pioneer Parent's operations and financial
     condition. Pollution and similar environmental risks generally are not
     fully insurable.



o    There are factors outside of Pioneer Parent's control which could impair
     its ability to satisfy its debt obligations. Pioneer Parent is a borrower
     under fixed term senior notes and a line of credit. The terms of Pioneer
     Parent's borrowings under the senior notes and the line of credit specify
     scheduled debt repayments and require Pioneer Parent to comply with
     covenants and restrictions. Pioneer Parent's ability to comply with the
     debt repayment terms, associated covenants and restrictions is dependent
     on, among other things, factors outside Pioneer Parent's direct control,
     such as commodity prices, interest rates and competition for available debt
     financing.



o    The oil and gas industry is highly competitive. Pioneer Parent competes
     with other companies, producers and operators for acquisitions and in the
     exploration, development, production and marketing of oil and gas. Some of
     these competitors have substantially greater financial and other resources
     than Pioneer Parent.



o    Present or future regulations could adversely affect Pioneer Parent's
     business and operations. Pioneer Parent's business is regulated by a
     variety of federal, state, local and foreign laws and regulations. There
     can be no assurance that present or future regulations will not adversely
     affect Pioneer Parent's business and operations.



o    Pioneer Parent has international operations which are subject to
     international economic and political risks. At December 31, 2000,
     approximately 22% of Pioneer Parent's proved reserves of oil, natural gas
     liquids and gas were located outside the United States (17% in Argentina,
     4% in Canada and 1% in South Africa). The success and profitability of
     international operations may be adversely affected by risks



                                      -22-
   33



     associated with international activities, including (1) economic and labor
     conditions, (2) political instability, (3) tax laws, including United
     States taxes on foreign subsidiaries, and (4) changes in the value of the
     United States dollar versus the local currency. To the extent that Pioneer
     Parent is involved in international activities, changes in exchange rates
     may adversely affect Pioneer Parent's consolidated revenues and expenses,
     as expressed in United States dollars.



o    Numerous uncertainties exist in estimating Pioneer Parent's quantities of
     proved reserves and future net revenues. Estimates of proved reserves and
     related future net revenues are based on various assumptions which may
     prove to be inaccurate. Therefore, those estimates should not be construed
     as being accurate estimates of the current market value of Pioneer Parent's
     proved reserves.





                                      -23-
   34


                                 SPECIAL FACTORS

BACKGROUND OF THE MERGER OF EACH PARTNERSHIP

     The partnerships were formed from 1981 through 1991 under the sponsorship
of various affiliated companies collectively known as Parker & Parsley. On
February 19, 1991, Parker & Parsley's principal company converted from limited
partnership form to corporate form and acquired most of the assets of five oil
and gas limited partnerships. The new corporation was called Parker & Parsley
Petroleum Company, and it owned the sole or managing general partners of the
partnerships.


     In early 1992, Parker & Parsley Petroleum Company decided that it could not
fully realize the benefits of the properties it had acquired while continuing to
devote substantial resources to the sponsorship of and drilling for each
partnership. It stopped sponsoring oil and gas development drilling and income
partnerships and focused on its corporate development. In 1997, Parker & Parsley
Petroleum Company and MESA Inc. combined their businesses in a merger that
created Pioneer Natural Resources Company. That same year, Pioneer Parent
combined many of its U.S. subsidiaries, including the managing or sole general
partner of each of the partnerships, into its main subsidiary, Pioneer USA.



     From time to time since 1992, Pioneer Parent and its predecessors have had
general, internal discussions about whether to consolidate each partnership
pursuant to a transaction such as the merger of each partnership. On several
occasions, Pioneer Parent or its predecessors engaged outside legal counsel and
had discussions with investment banks about a possible combination with each of
the partnerships. Some of those discussions were with Stanger. The contemplated
structure of the combination has varied significantly during these internal
discussions and has included issuances of common stock, combinations of common
stock and cash, and cash-only transactions through asset sales, mergers, tender
offers, and combinations of those types of transactions. See "Special Factors -
Reasons for the Merger of Each Partnership" for a discussion of why Pioneer
Parent and Pioneer USA selected the proposed transaction. In general, the
contemplated transactions would have been taxable to the limited partners of
each partnership because of the difficulties involved in structuring a tax-free
transaction for the partnership. Until 1999, every time Pioneer Parent or its
predecessors considered such a transaction, it decided not to complete the
transaction. The reasons Pioneer Parent and its predecessors did not previously
complete a transaction varied. In some early cases, they wanted to collect and
fully distribute proceeds to the limited partners of each partnership from
litigation against an oilfield services company before trying to value any
partnership. In other cases, they wanted to avoid periods of volatility in oil
and gas prices or in Pioneer Parent's stock price. On several occasions, Pioneer
Parent was involved in other corporate transactions that could not be completed
timely if a transaction with each partnership was also pending.



     In early 1998, Pioneer Parent was formulating a strategic plan to focus on
its 25 core area oil and gas fields and to eliminate ancillary operations.
Pioneer Parent began discussions internally to consider a transaction involving
each partnership, including the basis for valuing each partnership and whether
the consideration should be Pioneer Parent common stock, cash or some
combination of both.



     During the second quarter of 1998, Pioneer Parent and Pioneer USA began to
discuss the methods for valuing each partnership. At that time, the board of
directors of Pioneer USA engaged Sayles, Lidji & Werbner, A Professional
Corporation (then known as Sayles & Lidji, A Professional Corporation) based in
Dallas, Texas, as its independent legal counsel to assist the board in
evaluating a potential transaction with Pioneer Parent. Pioneer USA's board also
engaged Stanger as its financial advisor to review any proposed transaction and
to render an opinion as to the fairness of the offer price, from a financial
point of view, to the unaffiliated limited partners of each partnership. In May
1998, Pioneer Parent submitted an offer to merge each partnership into Pioneer
USA using Pioneer Parent common stock or a combination of Pioneer Parent common
stock and cash. The pricing for that offer was primarily based on oil and gas
prices and the present value of estimated future net revenues from each
partnership's oil and gas reserves, in each case as of December 31, 1997. The
present value of estimated future net revenues was determined in accordance with
the SEC's reporting convention that provides a common basis for comparing oil
and gas companies and requires the use of oil and gas prices as of the date of
computation, but using a 15% discount rate. After some negotiation with Pioneer
USA, Pioneer Parent withdrew the May 1998 offer due to the decline in oil
prices. In July 1998, Pioneer Parent submitted a second offer using Pioneer
Parent common stock, or at its option upon the occurrence of specified events, a
combination of Pioneer Parent common stock and cash. The oil and gas pricing for
the second offer was lower than the pricing in the May 1998 offer due to the
continued decline in oil prices, but the discount rate for the second offer was
the same as the May 1998 offer. Pioneer Parent and Pioneer USA decided to
discontinue further discussions and not to submit the proposed transaction to
the limited partners of any partnership because of:


     o    the continued decline in oil prices, which in turn would reduce any
          merger value to be paid to the limited partners of each partnership;


     o    the decline in Pioneer Parent's stock price; and



                                      -24-
   35



     o    the tight lending environment for many oil and gas companies,
          including Pioneer Parent.



     As oil and gas prices improved, in June 1999, Pioneer Parent and Pioneer
USA again began discussions internally to consider a transaction involving each
partnership. At that time, Scott Sheffield, the President and Chief Executive
Officer of Pioneer Parent, contacted members of Pioneer USA's board regarding
consideration of a potential transaction involving each partnership. Pioneer
Parent did not submit a written offer to Pioneer USA at that time.



     During the second quarter of 1999, Pioneer Parent and Pioneer USA attempted
to formally address the conflicting interests inherent in the relationships
among Pioneer Parent, Pioneer USA, each partnership and the officers and
directors of Pioneer Parent and Pioneer USA. Pioneer USA caused Scott D.
Sheffield to resign from Pioneer USA's board of directors because he is also a
member of Pioneer Parent's board of directors. He was not replaced. Pioneer USA
did not consider replacing Mr. Sheffield with an unaffiliated director because
Pioneer USA is a 100% subsidiary of Pioneer Parent and typically such
wholly-owned subsidiaries do not have unaffiliated directors. Because all of the
board members of Pioneer USA are also employees of Pioneer Parent, an inherent
conflict exists with respect to their duties to the limited partners of each
partnership in their capacity as directors of Pioneer USA, on the one hand, and
their duties to Pioneer Parent as employees, on the other hand.



     Shortly thereafter, Pioneer USA's board again engaged Sayles, Lidji &
Werbner to advise the board in connection with a proposed transaction with
Pioneer Parent and any other alternative transaction that the board determined
was worth consideration.


     Pioneer USA's board also engaged, on behalf of each partnership, Stanger,
as its financial advisor to advise the board on the fairness from a financial
point of view of the merger value for each partnership to be paid to the
unaffiliated limited partners in the partnership for the limited partnership
interests in the partnership and to assist in Pioneer USA's evaluation of the
merger transaction and other strategic alternatives. Stanger was familiar with
the circumstances from its 1998 engagement.

     On July 14, 1999, Pioneer USA's board met with its counsel and Stanger to
discuss the proposed merger of each partnership. Stanger presented an overview
of the analysis it planned to perform in evaluating the fairness of the proposed
transaction. Stanger advised Pioneer USA's board that Stanger would review the
following for each partnership:

     o    the reserve report to be prepared by Williamson Petroleum Consultants,
          Inc. as of September 30, 1999;

     o    the most recent quarterly financial statements;

     o    the estimated cash distributions;

     o    the estimated net asset value, going concern value and liquidation
          value;

     o    secondary market prices;

     o    tender offers; and

     o    repurchase offers.


Sayles, Lidji & Werbner then reviewed and discussed with the board the
procedures that would be involved in completing the proposed transaction with
Pioneer Parent. The discussion topics included:


     o    the process in which Pioneer USA's board of directors would approve
          the proposed transaction;

     o    the submission of the proposed merger of each partnership to the
          limited partners of the partnership for approval;

     o    the evaluation of offers from third parties;

     o    the application of and compliance with the requirements of the federal
          securities laws; and

     o    the timing of the proposed transaction.

     Members of the Pioneer USA board met informally on several occasions during
July and early August to discuss among each other the proposed terms of the
merger transaction and other potential alternative transactions, including the
formation of a royalty trust or a master limited partnership.


     On August 16, 1999, at a special meeting of the Pioneer USA board, the
board met with representatives of Sayles, Lidji & Werbner and Stanger to discuss
the proposed merger of each partnership into Pioneer USA. Pioneer USA's board
discussed with the representatives of Stanger and Sayles, Lidji & Werbner the
proposed terms of the offer expected from Pioneer Parent, including the expected
pricing parameters of $18 per Bbl of oil and $2.40 per Mcf of gas and the
expected timing of receipt of Pioneer Parent's formal written offer. Stanger
discussed the progress it was making on its financial analysis of each
partnership and its determination of the fairness from a financial point of view
of the merger value for each partnership to be paid in cash for the limited
partners' interests in the partnership. Stanger's discussion centered on (1) the
price to be paid for the oil and gas reserves, (2) the discount rate, (3) the
application of overhead charges and administrative charges, and (4) the
responsibility for any transaction expenses. Following this discussion, the
board and its counsel discussed the board's fiduciary duties in evaluating the
proposed transaction with Pioneer Parent and the making of a recommendation to
the unaffiliated




                                      -25-
   36


limited partners. Finally, the board decided to request that Pioneer Parent make
a formal written offer outlining the terms of the proposed merger transaction.



     On August 17, 1999, in response to Pioneer USA's request for a written
offer, Pioneer Parent delivered to Pioneer USA's board a written proposal which
outlined the terms of the proposed merger transaction. The written offer
specified that the pricing for the oil and gas reserves would be based on 95% of
the arithmetic average of a four-year or five-year NYMEX futures price. The
future cash flows generated by this pricing structure would then be discounted
using a 15% discount rate. At a special meeting that day of Pioneer USA's board,
the board, its counsel and Stanger met to discuss the specifics of Pioneer
Parent's offer, including oil and gas pricing, the present value discount rate,
the right to allow others to bid on the property, and the costs of the merger of
each partnership. Following the board meeting, Pioneer USA's directors
determined that it would be advantageous to each partnership to seek more
favorable pricing terms and a lower discount rate. Thus, the board decided to
continue discussions of the written offer.



     On August 23, 1999, at a special meeting of Pioneer USA's board, the board
updated its counsel and Stanger on the status of its discussions with Pioneer
Parent. As a result of continued discussions, Pioneer Parent and Pioneer USA
agreed, in response to requests by Stanger, (1) to reduce the discount rate from
15% to 12.5%, (2) to increase the pricing of the oil reserves from 95% of the
arithmetic average of a four-year or five-year NYMEX futures price to 100% of
the arithmetic average of the five-year NYMEX futures price, (3) to a fixed
price of $2.40 per Mcf of gas instead of a floating NYMEX futures price and (4)
to allocate the merger expenses and fees to each participating partnership.



     On September 2, 1999, at a special meeting of Pioneer USA's board, the
board and representatives of Stanger and Sayles, Lidji & Werbner reviewed the
terms of a revised proposal submitted by Pioneer Parent which incorporated these
changes. The parties discussed the revised terms of the merger of each
partnership and the strategic rationale for and benefits of the merger of each
partnership. At this meeting, Stanger reviewed with the board its financial
analysis and its evaluation of the merger consideration and the feasibility of
other strategic alternatives. Stanger also orally presented to the board the
status of its findings and its preliminary evaluation of the proposed
transaction.


     After considering Stanger's evaluation of the proposed merger transaction,
Pioneer USA's board, together with representatives of Stanger, engaged in a
general discussion of other possible transactions it had considered over the
last six to eight months. This discussion included anticipated ongoing
operations of each partnership under its current structure and the operation of
each partnership through a master limited partnership structure, as well as
through a royalty trust. The board discussed selling the oil and gas properties
of each partnership at auction and potentially soliciting other buyers or merger
partners. The board also considered the fact that other potential buyers of each
partnership would have an opportunity to make an offer for each partnership
before the board submitted the merger transaction to the limited partners of
each partnership for their consideration and approval.

     At a special meeting held on September 8, 1999, Pioneer USA's board
continued discussions with Sayles, Lidji & Werbner and Stanger regarding the
merger proposals for each partnership. After considering the alternatives
discussed in the preceding paragraph, including the advantages and disadvantages
of each, the board concluded that none of the alternatives was more advantageous
to the limited partners of any partnership than the terms of the proposed merger
of the partnership. The board then unanimously approved proceeding with the
merger of each partnership, subject to determination of September 30, 1999
pricing, its receipt of Stanger's fairness opinion, and the board's
determination that the merger consideration of each partnership is fair to the
unaffiliated limited partners of that partnership based on all circumstances as
of September 30, 1999, including without limitation, the then current market
conditions and the existence, if any, of any other proposal for the partnership
on terms more favorable to the limited partners.


     On September 8, 1999, in connection with the proposed merger transaction,
Pioneer Parent and Pioneer USA filed a preliminary proxy statement and
preliminary Schedule 13e-3s with the Securities and Exchange Commission. In
addition, Pioneer Parent and Pioneer USA publicly announced the proposed merger
of each partnership. In that announcement, Pioneer USA also announced that it
would consider proposals from other potential buyers of one or more of the
partnerships.



     On or about October 19, 1999, Pioneer Parent submitted a verbal offer to
Pioneer USA to revise the oil reserve component of the pricing used in the
preliminary proxy statement to $18.35 per Bbl of oil. On or about November 3,
1999, Pioneer Parent submitted a second verbal offer to Pioneer USA to further
revise the oil reserve pricing to $18.40 per Bbl of oil. Later that month, due
to the increase in oil and gas prices over the previous several months and in
response to a request from Pioneer USA, Pioneer Parent proposed to Pioneer USA
that the merger value calculation for each partnership be further modified (1)
to increase the pricing to $18.90 per Bbl for oil and $2.55 per Mcf of gas and
(2) to increase the discount rate to 15%.



                                      -26-
   37



     On November 17, 1999, in connection with the approval of Pioneer Parent's
capital budget for 2000, Pioneer Parent's board of directors met and voted to
approve the merger of each partnership and to proceed with the completion of
each merger, subject to the pricing information and other relevant conditions at
the time.



     At a special board meeting held on November 22, 1999, Pioneer USA's board
of directors met with representatives from Stanger and Sayles, Lidji & Werbner
to discuss Pioneer Parent's proposed pricing. Pioneer USA's board agreed that an
increase in the merger value for each partnership based on Pioneer Parent's
proposed pricing was warranted to more closely reflect the current oil and gas
prices. Similarly, in view of increases in interest rates during the months
since the original proposal was made and in view of the volatility of oil and
gas prices over the previous year, Pioneer USA's board agreed to increase the
discount rate used to determine the merger value for each partnership from 12.5%
to 15%. Pioneer USA's board reported that management had worked to reduce the
expected merger expenses and fees from an estimated $4.6 million to an estimated
$1.8 million, thereby increasing the merger value for each partnership to be
received by the limited partners of the partnership. The board also received a
status report on whether or not any third party offers had been received since
September 8, 1999, the date on which Pioneer Parent and Pioneer USA announced
that it would consider such offers. In that regard, Pioneer Parent and Pioneer
USA had not received any formal offers, but did receive a few inquiries from
third parties expressing an interest in possibly making a bid on one or more of
the partnerships or the assets of one or more of the partnerships. The nature of
the inquiries was to understand the structure and pricing of the transaction
proposed by Pioneer and Pioneer USA. None of the third parties who made
inquiries (1) specified any terms, (2) made any offer or (3) have pursued the
matter further. The board then voted to extend the period it would be willing to
consider third party offers from November 1, 1999 to December 31, 1999. Stanger
then reviewed for the board Stanger's analysis of the fairness of the merger
transaction using the new terms agreed to by Pioneer Parent and Pioneer USA.
Stanger expressed its preliminary view that the revised merger value for each
partnership to be paid in cash for the limited partnership interests in each
partnership would be fair from a financial point of view to the unaffiliated
limited partners of the partnership under recent market conditions, but stated
that whether or not the transaction would be considered fair by Stanger at the
time its fairness opinion was sought would depend on market conditions at that
time. Following this discussion, the board approved proceeding with the merger
of each partnership on the new terms, subject to (1) its receipt of a fairness
opinion from Stanger, and (2) its determination that the merger value to be paid
in cash for the limited partnership interests in each partnership is fair to the
unaffiliated limited partners of the partnership based on all circumstances,
including without limitation, the then current market conditions and the
existence, if any, of any other proposal for such partnership or its assets on
terms more favorable to the unaffiliated limited partners than the proposed
merger transaction.



     In December 1999, Pioneer became involved in discussions with an
independent oil and gas company similar in size to Pioneer relating to a
corporate merger opportunity. Those discussions required the dedicated time and
attention of Pioneer's management. The corporate merger opportunity subsequently
failed to come to fruition. Meanwhile, during December 1999 and the first
quarter of 2000, oil and gas prices continued to increase. As a result, during
the first quarter of 2000, Pioneer Parent and Pioneer USA began to discuss
revising the pricing terms of the proposed merger transaction to (1) an
arithmetic average of the five-year NYMEX futures price for oil and for gas and
(2) a 15% discount rate. Pioneer Parent also proposed to offer Pioneer Parent
common stock instead of cash to the limited partners of each participating
partnership. In April 2000, Pioneer Parent and Pioneer USA discontinued these
discussions and did not submit the proposed merger transaction to the limited
partners of any partnership because of:



          o    the decline in Pioneer Parent's stock price;


          o    the increase in interest rates; and


          o    Pioneer Parent's involvement in replacing existing debt with new
               publicly-held debt and a new credit facility.



     In September 2000, Pioneer Parent and Pioneer USA began internal
discussions to consider a merger transaction involving 13 privately-held
employee limited partnerships. Pioneer Parent offered to pay an amount of cash
to the limited partners of each participating partnership equal to the sum of
the present value of estimated future net revenues from the partnership's
estimated oil and gas reserves and its net working capital, in each case as of
September 30, 2000, less the cash distributions on October 15, 2000 and November
15, 2000, by the partnership to its partners. Pioneer Parent and Pioneer USA
calculated the present value of the estimated future net revenues from each
partnership's estimated oil and gas reserves using (1) a five-year NYMEX futures
price for oil and gas as of August 25, 2000, with prices held constant after
year five at the year five price, less standard industry adjustments, (2)
historical operating costs adjusted only for those items affected by commodity
prices, such as production taxes and ad valorem taxes, and (3) a 13.5% discount
rate. Pioneer Parent also agreed to bear the merger expenses and fees. Using the
same parameters as described above, Pioneer Parent purchased all of the direct
oil and gas interests held by Scott D. Sheffield, its chairman of the board of
directors and chief executive officer, for $0.2 million during October 2000. The
consideration paid in the mergers of the employee limited partnerships and in
the purchase of the direct oil and gas interests was all cash since offering and
registering Pioneer Parent common stock in those transactions was
cost-prohibitive due to the small size of such transactions. In December 2000,
Pioneer Parent and



                                      -27-
   38



Pioneer USA completed the merger of each of the 13 privately-held employee
limited partnerships with and into Pioneer USA.



     In October 2000, Pioneer Parent terminated the preliminary proxy statement
and preliminary Schedule 13e-3s filed with the Securities and Exchange
Commission on September 8, 1999 in connection with the proposed merger
transaction.



     As oil and gas prices continued to improve, in January 2001, Pioneer Parent
and Pioneer USA renewed their internal discussions to consider a transaction
involving each of the partnerships described in this document. For a discussion
of why Pioneer Parent and Pioneer USA selected the proposed merger transaction,
see "Alternative Transactions to the Merger of Each Partnership" on page 41.
Pioneer Parent offered a combination of its common stock and cash. Pioneer
Parent and Pioneer USA agreed on a merger value for each participating
partnership equal to the sum of the present value of estimated future net
revenues from the partnership's estimated oil and gas reserves and its net
working capital, in each case as of March 31, 2001. Pioneer Parent and Pioneer
USA agreed to calculate the present value of the estimated future net revenues
from each partnership's estimated oil and gas reserves using (1) a five-year
NYMEX futures price for oil and gas as of March 30, 2001, with prices held
constant after year five at the year five price, less standard industry
adjustments, (2) historical operating costs adjusted only for those items
affected by commodity prices, such as production taxes and ad valorem taxes, and
(3) a 13.5% discount rate. For 2001, the oil and gas prices would be based on
the average NYMEX futures price for the nine-month period beginning on April 1,
2001 and ending December 31, 2001. Pioneer Parent also agreed to bear the merger
expenses and fees.



     On February 15, 2001, Pioneer Parent's board of directors met and voted to
approve the merger of each partnership, the issuance of Pioneer Parent common
stock and the payment of cash upon each such merger, and to otherwise proceed
with the completion of each merger, subject to the pricing information and other
relevant conditions at the time.



     During March 2001, Pioneer Parent offered to acquire all of the direct oil
and gas interests owned by some former officers and employees of Pioneer Parent
and Pioneer USA in properties in which Pioneer Parent and Pioneer USA own
interests. The merger value for the direct oil and gas interests was equal to
the present value of estimated future net revenues from the oil and gas reserves
attributable to the interests, as of March 31, 2001. In determining the present
value, Pioneer Parent and Pioneer USA used (1) a five-year NYMEX futures price
for oil and gas as of March 19, 2001 with prices held constant after year five
at the year five price, less standard industry adjustments, (2) historical
operating costs adjusted only for those items affected by commodity prices, such
as production taxes and ad valorem taxes, and (3) a 13.5% discount rate. The
consideration offered in the purchases of the direct oil and gas interests was
all cash since offering and registering Pioneer Parent common stock in those
purchases was cost-prohibitive due to the small size of such transactions.


     In April 2001, Pioneer USA contacted Sayles, Lidji & Werbner and Stanger to
advise them of the proposed merger transaction, pricing terms and merger
consideration.

     On April 9, 2001, Pioneer USA's board met with Sayles, Lidji & Werbner to
discuss the proposed merger of each partnership into Pioneer USA. The board
members reviewed the terms of the merger transaction, including the pricing
terms, the merger consideration and the terms and conditions of the proposed
merger agreement. The board members also discussed the engagement of special
legal counsel to render the legal opinion required by each partnership's
partnership agreement. Finally, Pioneer USA's board discussed the fairness
opinion to be delivered by Stanger and decided to hold another board meeting at
which Stanger would present in detail its methodology in determining that the
merger value for each partnership and the allocation of the merger value of the
partnership (1) to the limited partners of the partnership as a group, (2) to
the general partners of the partnership as a group, (3) to Pioneer USA as the
managing or sole general partner of the partnership, (4) to the unaffiliated
limited partners of the partnership as a group and (5) to the unaffiliated
limited partners of the nonmanaging general partner, if any, of the partnership
as a group, is fair to the unaffiliated limited partners of the partnership and
the unaffiliated limited partners of the nonmanaging general partner, if any, of
the partnership, from a financial point of view. The board decided to proceed
with the merger transaction, but would withhold recommending the merger
transaction to the limited partners or executing the merger agreement until it
received the fairness opinion from Stanger and determined that the merger of
each partnership is advisable, fair to the unaffiliated limited partners and in
the unaffiliated limited partners' best interests


     On April 17, 2001, in connection with the proposed merger transaction,
Pioneer Parent and Pioneer USA filed a registration statement on Form S-4 and
preliminary Schedule 13e-3s with the Securities and Exchange Commission. In
addition, Pioneer Parent and Pioneer USA publicly announced the proposed merger
of each partnership. In that announcement, Pioneer USA also announced that it
would continue to consider proposals from other potential buyers of any
partnership or its assets.



     On May 7, 2001, Pioneer USA received proposed solicitation materials
prepared by Sierra Fund 3 indicating that Sierra Fund planned to make a tender
offer for up to 4.9% of the limited partnership interests of Parker & Parsley
88-A, L.P. and Parker & Parsley 89-A, L.P. at a price equivalent to $200 and
$240 per $1,000 initial investment, respectively, in each of the partnerships.
Sierra Fund requested and received a list of limited partners of these
partnerships. On June 28, 2001, Pioneer USA learned that on June 14, 2001 Sierra
Fund made a tender offer for up to 4.9% of the limited partnership interests of
Parker & Parsley 83-A, Ltd., Parker & Parsley 83-B, Ltd., Parker & Parsley 84-A,
Ltd. and Parker & Parsley 85-A, Ltd. at a price equivalent to $85, $75, $110 and
$80 per $1,000 investment, respectively, in each of the partnerships.


                                      -28-
   39






     Three other limited partners have expressed interest to Pioneer USA in
either making offers for the assets of particular partnerships or in purchasing
the limited partnership interests of other limited partners. In May 2001,
Salvage Investors, L.L.C. expressed interest in making an offer for the assets
of Parker & Parsley 82-I, Ltd. but did not indicate a price at which it would be
willing to purchase those assets. Also in May 2001, Horace Potts IV expressed
interest in making an offer for the assets of unspecified partnerships or,
alternatively, in soliciting higher offers on the assets of those partnerships,
but did not indicate a price at which he would be willing to purchase those
assets. In June 2001, Nancy R. Schauer expressed interest in purchasing limited
partnership interests of Parker & Parsley 87-A Conv., Ltd., Parker & Parsley
87-B Conv., Ltd. and Parker & Parsley Private Investment 88, L.P. Pioneer USA
received a copy of correspondence from Ms. Schauer to the limited partners of
those partnerships in which Ms. Schauer asked the limited partners to vote
against the proposed mergers and to call her if they wanted to sell their
limited partnership interest.



     Additionally, in May 2001 James A. Smith of Indigo Ventures requested, and
Pioneer later sent to him, a list of the limited partners of Parker & Parsley
Private Investment 89, L.P. and Parker and Parsley 90 Spraberry Private
Development, L.P. Pioneer Parent and Pioneer USA do not know if Mr. Smith
contacted any limited partners of those partnerships.



     In late April 2001, Stanger contacted members of Pioneer USA's board and
expressed concern regarding the pricing terms of the merger transaction. Based
on Stanger's updated analysis of the new pricing terms for the merger
transaction, Stanger questioned whether merger value was fair to the
unaffiliated limited partners of the partnerships and the unaffiliated limited
partners of the nonmanaging general partners of the partnerships from a
financial point of view. After internal discussions between members of Pioneer
USA's board and Stanger to discuss pricing terms which Stanger and the Pioneer
USA board believed would be fair to the unaffiliated limited partners of the
partnerships and the unaffiliated limited partners of the nonmanaging general
partners of the partnerships from a financial point of view, the Pioneer USA
board requested that Stanger meet with Pioneer Parent to discuss the issue.
Stanger met with Pioneer Parent on June 15, 2001, to discuss new pricing terms
that were more favorable to the partnerships.



     On June 18, 2001, in follow-up discussions between Pioneer Parent, Pioneer
USA and Stanger, Pioneer Parent and Pioneer USA orally agreed, subject to the
approval of their respective boards, to revise the pricing terms of the merger
transaction as follows: (1) that the merger value for each partnership would
equal the sum of the partnership's reserve value and its working capital, in
each case as of March 31, 2001, less the cash distribution to be paid in July
2001 and less the partnership's pro rata share of expenses and fees to be
incurred in connection with the mergers of all of the partnerships, except that
Pioneer Parent will pay (A) any such expenses and fees in excess of $2,000,000
in the aggregate and (B) a portion of such expenses and fees otherwise allocable
to any nonparticipating partnership, (2) to reduce the discount rate that would
be used in calculating the present value of the estimated future net revenues
from 13.5% to 10%, (3) to change the composition of the payment of the merger
value for each partnership from 25% in cash and 75% in shares of Pioneer Parent
common stock to 100% in shares of Pioneer Parent common stock based on the
average closing price of the Pioneer Parent common stock, as reported by the New
York Stock Exchange, for the ten trading days ending three days business days
before the date of the special meeting of the partnership, and (4) to engage
Williamson Petroleum Consultants, Inc. to review the estimate of each
partnership's reserves and the present value of the estimated future net
revenues from those estimated reserves as of March 31, 2001. The effect of the
revised pricing terms was to increase the merger consideration that would be
paid to each of the participating partnerships upon completion of the merger
transaction.



     On June 21, 2001, Pioneer Parent's board met and approved the revised
pricing terms.



     At a special meeting held on June 21, 2001, Pioneer USA's board continued
discussions with Sayles, Lidji & Werbner and Stanger regarding the merger
proposals for each partnership. Stanger also orally presented to Pioneer USA's
board the status of its findings and its preliminary evaluation of the proposed
transaction based on the new pricing terms for the merger transaction. Pioneer
USA's board decided that it would take the approval of the merger of each
partnership under advisement, so that the board members could review the written
presentation materials provided by Stanger and the revised written offer to be
submitted by Pioneer Parent, and agreed to convene a special meeting on June 25,
2001.



     On June 22, 2001, Pioneer submitted its written offer with the revised
pricing terms to Pioneer USA.



     On June 25, 2001, Pioneer USA's board held a special meeting with Sayles,
Lidji & Werbner and Stanger to discuss the merger proposals for each partnership
and Stanger's fairness opinion. The board then unanimously approved proceeding
with the merger of each partnership, subject to (1) the execution of a
definitive merger agreement, (2) its receipt of Stanger's fairness opinion, and
(3) its receipt of the Securities and Exchange


                                      -29-
   40



Commission's declaration that the registration statement, that includes this
document, is effective under the Securities Act of 1933.



     In a special meeting of the board of Pioneer USA held on            , 2001,
Stanger presented its opinion dated           , 2001, that the merger value for
each partnership and the allocation of the merger value of the partnership (1)
to the limited partners of the partnership as a group, (2) to the general
partners of the partnership as a group, (3) to Pioneer USA as the managing or
sole general partner of the partnership, (4) to the unaffiliated limited
partners of the partnership as a group and (5) to the unaffiliated limited
partners of the nonmanaging general partner, if any, of the partnership as a
group, is fair to the unaffiliated limited partners of the partnership and the
unaffiliated limited partners of the nonmanaging general partner, if any, of the
partnership, from a financial point of view. The board of Pioneer USA then
unanimously determined that the merger proposals for each partnership are
advisable, fair to the unaffiliated limited partners and in the unaffiliated
limited partners' best interests. Accordingly, the board recommended that the
unaffiliated limited partners of each partnership vote for the merger proposals.
References to Pioneer USA's board's recommendation of the merger of each
partnership and its finding that the merger consideration is fair from a
financial point of view are stated in this preliminary document conditioned on
the execution of a definitive merger agreement and its receipt of Stanger's
fairness opinion, which are expected to occur when the registration statement
that includes this document is declared effective under the Securities Act of
1933.


REASONS FOR THE MERGER OF EACH PARTNERSHIP


     General. For all of the reasons listed below, Pioneer Parent believes that
it is the party in the position to pay the highest price for the limited
partnership interests of each partnership. Pioneer USA also believes that
Pioneer Parent is the most likely buyer for each partnership's properties in
light of:


     o    Pioneer USA's operation of most of the properties;

     o    Pioneer USA's extensive property holdings in the same fields; and


     o    Pioneer Parent's ability to achieve efficiencies by consolidating
          operations with its existing operations in the same areas.



     Pioneer Parent's Reasons. Pioneer Parent believes that completion of the
merger of each partnership at this time is advantageous to it for the following
reasons:



     o    Consolidate Core Area of Operations. The Spraberry field of the
          Permian Basin is one of Pioneer Parent's 25 fields of focus in its
          strategic plan. Acquisition of each partnership's properties would
          help consolidate Pioneer Parent's operations in the Spraberry field
          and achieve operating efficiencies. Pioneer USA operates most of each
          partnership's wells, and Pioneer Parent has extensive properties
          around each partnership's properties, including interests in most of
          each partnership's wells.



     o    Achieve Operating Efficiencies. Pioneer Parent expects to improve
          operating efficiencies with respect to the properties acquired in the
          merger of each partnership because it will be able to co-mingle
          production of oil from each participating partnership's properties
          with production of oil from other Pioneer Parent properties for
          storage, transportation and sale. Production of oil from each
          partnership's properties is predominantly segregated from Pioneer
          Parent's production of oil until sale. Gas production is currently,
          and will continue to be, metered, which means that it is measured and
          allocated based on ownership.



     o    Achieve Administrative Efficiencies. Pioneer Parent will eliminate the
          costs, including time spent by Pioneer Parent employees, related to
          preparing and filing each partnership's separate tax returns,
          financial statements and, for each reporting partnership, reports with
          the SEC, as well as dealing with the concerns of approximately 29,000
          record limited partners. The merger of each partnership will result in
          administrative efficiencies and cost reductions in the management and
          operation of the properties now owned by each partnership,
          particularly in the areas of audit, accounting and tax services,
          engineering services, bookkeeping, data processing, record maintenance
          and mailing information to the partners. Although Pioneer Parent will
          lose the benefit of each partnership's reimbursement for general and
          administrative expenses, it will be able to use the additional time of
          its personnel to help achieve its corporate strategic goals.


     Pioneer USA's Reasons. In considering the merger of each partnership, the
board of directors of Pioneer USA considered the benefits to the limited
partners of each partnership set forth on page 7 as well as the following
factors:


     o    Maturity of Partnerships and Properties. Although each partnership's
          properties were long-lived at the formation of the partnership, each
          partnership's properties are now mature, ranging from approximately 10
          to approximately 20 years old. Pioneer Parent and Pioneer USA
          anticipated that at some point each



                                      -30-
   41

          partnership would need to be liquidated. Pioneer USA is recommending
          the merger transaction for each partnership at this time because:


          -    Pioneer USA believes that Pioneer Parent is the most likely buyer
               and is the only potential buyer with an offer outstanding. While
               third parties have made inquiries, no one except Pioneer Parent
               has made an offer to Pioneer USA to acquire any of the
               partnerships.



          -    Oil and gas prices have recovered from significant lows in 1998.
               As a result, Pioneer USA believes that Pioneer Parent's pricing
               is higher than it would have been otherwise.



          -    As our production continues to decline, administrative expenses
               for each partnership are increasing on a per BOE produced basis.
               Moreover, the administrative cost of continuing to produce each
               partnership to depletion could be significant, especially if no
               buyer is available at the time each partnership is shut down.



          -    As discussed below, the tax incentive for which each partnership,
               other than Parker & Parsley Producing Properties 87-A, Ltd.,
               Parker & Parsley Producing Properties 87-B, Ltd. and Parker &
               Parsley Producing Properties 88-A, L.P., was originally formed
               has been realized.


     o    Declining Cash Flows. As each partnership's properties have matured,
          the net cash flows from operations for the partnership have generally
          declined, except in periods of substantially increasing commodity
          prices. See Table 7 of Appendix A for each partnership's historical
          cash distributions. The marginal benefit of continuing the operations
          of each partnership is offset by the related administrative costs.
          These administrative costs consume an increasing amount, and
          ultimately will consume the entire amount, of the cash flows of each
          partnership as production declines.


     o    Tax Incentive Has Been Realized. Each partnership, other than Parker &
          Parsley Producing Properties 87-A, Ltd., Parker & Parsley Producing
          Properties 87-B, Ltd. and Parker & Parsley Producing Properties 88-A,
          L.P., was intended to provide to its partners federal income tax
          deductions for intangible drilling and development costs incurred by
          the partnership in the initial years of investment. Pioneer USA
          believes that the tax incentives have generally been realized.


     o    Partnership Tax Burdens May Now Exceed Benefits. As net cash flow
          available for distribution of each partnership has declined or, at
          times, disappeared, some limited partners of the partnership may incur
          greater costs to include their share of the tax information of the
          partnership in their returns than they receive in cash distributions.
          In any event, all limited partners of each partnership are expected to
          benefit by the elimination of the obligation to include partnership
          information in their tax returns for the years after the merger of
          each partnership in which they own interests.


     o    Each Partnership is Unable to Access Additional Capital. Pioneer
          Parent, through its subsidiary, Pioneer USA, has the ability,
          financial and otherwise, to take advantage of corporate opportunities
          to expand its reserve base through acquisitions. None of the
          partnerships has the ability to raise capital for reserve
          acquisitions. The partnership agreements of the partnerships do not
          authorize the partnerships to raise additional capital, whether debt
          or equity. Even if the partnership agreement of each partnership is
          amended to authorize additional capital, Pioneer Parent does not
          believe that the limited partners of the partnership would desire to
          contribute additional capital or to apply all cash flow to debt
          service, while remaining taxable on the related income.


     o    Fairness of Procedures. Pioneer USA considered the following factors
          in making its recommendation that the unaffiliated limited partners
          vote for the merger proposals for each partnership in which they own
          interests:


          -    None of the partnerships has any employees or directors, and all
               of Pioneer USA's directors are officers of Pioneer USA and of
               Pioneer Parent. As a result, there has been no approval by
               directors who are not Pioneer Parent employees.


          -    Pioneer USA did not retain an unaffiliated representative to act
               solely on behalf of the unaffiliated limited partners of each
               partnership for purposes of negotiating the terms of the merger
               of the partnership or preparing a report concerning the fairness
               of the merger of the partnership.

          -    Since Pioneer USA is entitled to vote its limited partnership
               interests other than as described below, the transaction is not
               structured so that the approval of at least a majority of
               unaffiliated limited partnership interests is required. Pioneer
               USA intends to vote in favor of the transaction for the
               partnership interests it holds as a limited partner of each
               partnership as permitted by the partnership agreement of each
               partnership except in the following partnerships where the
               partnership agreement does not allow Pioneer USA to vote on the
               proposed transaction:


                                      -31-
   42


                      Parker & Parsley 85-A, Ltd.
                      Parker & Parsley 85-B, Ltd.
                      Parker & Parsley Private Investment 85-A, Ltd
                      Parker & Parsley Selected 85 Private Investment, Ltd
                      Parker & Parsley Private Investment 86, Ltd.
                      Parker & Parsley 91-A, L.P.
                      Parker & Parsley 91-B, L.P.

          Despite the foregoing factors, Pioneer USA believes each merger is
          procedurally fair to the unaffiliated limited partners of each
          partnership because:


          -    Pioneer USA has been willing to consider any offer from third
               parties to purchase any partnership or the assets of any
               partnership since September 8, 1999, and will continue to do so
               through August 1, 2001; and



          -    Pioneer Parent does not directly own any partnership interests in
               the partnerships. Pioneer Parent beneficially owns all of Pioneer
               USA's partnership interests in the partnerships. Pioneer USA does
               not beneficially own more than 5% of the outstanding limited
               partnership interests in any partnership, except Parker & Parsley
               81-I, Ltd., Parker & Parsley 82-I, Ltd. and Parker & Parsley
               82-III, Ltd. In those partnerships, Pioneer USA repurchased and
               now owns partnership interests representing the following
               beneficial ownership percentages:


                      Parker & Parsley 81-I, Ltd.                        5.84%
                      Parker & Parsley 82-1, Ltd.                       10.73%
                      Parker & Parsley 82-III, Ltd.                      5.97%


               Except as set forth above, none of Pioneer Parent, Pioneer USA,
               or, to the knowledge of Pioneer USA, any of their directors or
               executive officers, or any associate or subsidiary of Pioneer
               Parent, Pioneer USA beneficially owns any partnership interests
               of any partnership. As a result, Pioneer USA believes that
               neither it nor its affiliates have a meaningful voting percentage
               for any partnership, other than Parker & Parsley 81-I, Ltd.,
               Parker & Parsley 82-I, Ltd. and Parker & Parsley 82-III, Ltd. See
               "Ownership of Partnership Interests" on page 64 of this document
               and Table 6 of Appendix A to this document.


     o    Fairness of Transaction. Pioneer USA's board of directors determined
          that the merger of each partnership is advisable, fair to the
          unaffiliated limited partners of the partnership and in their best
          interests. In reaching this determination for each partnership,
          Pioneer USA's board of directors considered the following factors:

          -    The form and amount of consideration offered to the partners of
               the partnership;

          -    The objectives of the merger of the partnership, including
               providing liquidity to the partners;

          -    Pioneer USA's right to consider third party offers;

          -    The current market prices for oil and gas, including the increase
               in market prices, and the subsequent increase in merger value for
               the partnership, since the merger transaction was initially
               proposed in 1999;

          -    The historical market prices for oil and gas;

          -    The net book value, going concern value and liquidation value of
               the partnership;

          -    The purchase prices paid in previous repurchases by Pioneer USA;

          -    The trading price of limited partnership interests in secondary
               market transactions

          -    The analysis of alternative transactions to the proposed merger
               of each partnership; and

          -    The fairness opinion of Stanger, including the analyses conducted
               by Stanger in rendering the fairness opinion.


RECOMMENDATION OF PIONEER USA


     On            , 2001, Pioneer USA's board of directors unanimously
determined that the merger of each partnership is advisable, fair to the
unaffiliated limited partners of the partnership, and in their best interests.
PIONEER USA'S


                                      -32-
   43

BOARD OF DIRECTORS RECOMMENDS THAT THE UNAFFILIATED LIMITED
PARTNERS VOTE FOR THE MERGER PROPOSALS FOR EACH PARTNERSHIP IN WHICH THEY OWN
INTERESTS.

     In making this recommendation, Pioneer USA's board of directors considered
a number of factors, including (1) the reasons for the merger of each
partnership set forth above in "Special Factors -- Reasons for the Merger of
Each Partnership," such as the fairness opinion and analyses conducted by
Stanger, and (2) the matters described under "Risk Factors" beginning on page 17
of this document, such as its conflicting interests. Pioneer USA's board of
directors also considered the likelihood, benefits and costs of other
transactions, including possible third party offers. Pioneer USA will consider
any offers from third parties to purchase any partnership or its assets. See
"The Merger of Each Partnership -- Third Party Offers" on page 52 of this
document for a description of the procedures for these offers. In view of the
numerous factors taken into consideration, Pioneer USA's board of directors did
not consider it practical to, and did not attempt to, quantify or assign
relative weights to the factors considered by it in reaching its decision to
recommend the merger of each partnership. Rather, the board viewed its position
and recommendation as being based on the total information presented to and
considered by the board.

FAIRNESS OPINION


     Pioneer USA, on behalf of each partnership, engaged Robert A. Stanger &
Co., Inc., an independent financial advisory firm, to conduct an independent
review and deliver a written opinion in connection with the merger of each
partnership that the merger value for each partnership and the allocation of the
merger value of the partnership (1) to the limited partners of the partnership
as a group, (2) to the general partners of the partnership as a group, (3) to
Pioneer USA as the managing or sole general partner of the partnership, (4) to
the unaffiliated limited partners of the partnership as a group and (5) to the
unaffiliated limited partners of the nonmanaging general partner, if any, of the
partnership as a group, is fair to the unaffiliated limited partners of the
partnership and the unaffiliated limited partners of the nonmanaging general
partner, if any, of the partnership, from a financial point of view. The full
text of Stanger's fairness opinion is attached as Appendix D to this document
and is incorporated into this document by reference. Limited partners of each
partnership are urged to read the opinion in its entirety. This summary of
Stanger's fairness opinion is qualified in its entirety by reference to the full
text of the opinion. Stanger has advised us that arriving at a fairness opinion
is a complex analytical process not necessarily susceptible to partial analysis
or amenable to summary description. For a more complete description of the
assumptions and qualifications to the fairness opinion see "Qualifications to
Fairness Opinion" beginning below on this page and "Assumptions" on page 39.


     Except for assumptions which Pioneer USA advised Stanger would be
reasonable and appropriate in its view, neither Pioneer USA nor any partnership
imposed any conditions or limitations on the scope of the investigation by
Stanger or the methods and procedures to be followed by Stanger in rendering the
fairness opinion. In addition, each partnership has agreed to indemnify Stanger
against some liabilities arising out of Stanger's engagement to prepare and
deliver its opinion upon consummation of the merger of the partnership, and such
indemnification obligations will become obligations of Pioneer USA.

     Experience of Stanger. Since its founding in 1978, Stanger has provided
information, research, investment banking and consulting services to clients
located throughout the United Sates, including major New York Stock Exchange
member firms and insurance companies and over seventy companies engaged in the
management and operation of partnerships. The investment banking activities of
Stanger include financial advisory and fairness opinion services, asset and
securities valuations, industry and company research and analysis, litigation
support and expert witness services, and due diligence investigations in
connection with both publicly registered and privately placed securities
transactions.


     Stanger was selected because of its experience in the valuation of
businesses and their securities in connection with mergers, acquisitions,
reorganizations and for estate, tax, corporate and other purposes, including the
valuation of partnerships, partnership securities and the assets typically held
through partnerships including oil and gas assets. Pioneer USA has previously
engaged Stanger to provide financial advisory services in connection with
proposed transactions between one or more of the partnerships and Pioneer Parent
which were never consummated.


     Qualifications to Fairness Opinion. In the fairness opinion, Stanger
specifically states that it was not requested to, and did not:

     o    make any recommendations to Pioneer USA, any partnership or the
          limited partners of any partnership with respect to whether to approve
          or reject the merger of any partnership;

     o    determine or negotiate the amount or form of the merger value for any
          partnership to be paid for limited partners' interests in the merger
          of the partnership;

     o    offer the assets of any partnership for sale to any third party;

     o    express any opinion as to:


                                      -33-
   44


          -    the impact on Pioneer USA or the limited partners of any
               partnership that does not participate in the proposed merger
               transaction;

          -    the tax consequences of the merger of any partnership for Pioneer
               USA, the nonmanaging general partner, if any, of the partnership
               or the limited partners of the partnership;


          -    Pioneer USA's or Pioneer Parent's ability to finance their
               obligations under the merger agreement or the impact of a failure
               to obtain financing on the financial performance of Pioneer USA,
               Pioneer Parent or any partnership;



          -    Pioneer USA's decision to estimate the reserve value of the oil
               and gas reserves of each partnership based upon the continued
               operation of the properties by Pioneer USA and the payment of
               overhead charges in accordance with existing operating agreements
               or the impact, if any, on the estimated value of each
               partnership's oil and gas reserves if Pioneer Parent and Pioneer
               USA determined to offer or operate the assets subject to revised
               operating agreements;


          -    whether or not alternative methods of determining the merger
               value for each partnership would have also provided fair results
               or results substantially similar to the methodology used;

          -    alternatives to the merger of each partnership, including the
               offering of such assets for sale to third party buyers;


          -    the trading price of shares of Pioneer Parent common stock
               immediately following the closing of the merger of each
               partnership and the distribution of shares of Pioneer Parent
               common stock in connection with the merger of each partnership;


          -    the fairness of the termination of the repurchase obligations of
               Pioneer USA with respect to some partnerships, which repurchase
               obligations require Pioneer USA to offer to repurchase limited
               partnership interests annually based upon a formula which in some
               circumstances, including the repurchase offers based upon
               December 31, 2000 oil and gas prices, result in repurchase offer
               prices above the market value for the reserves of any such
               partnership; or

          -    any other terms of the merger of any partnership.

     Summary of Material Considered and Investigation Undertaken. Stanger's
analysis of the merger of each partnership involved a review of the following
information:

     o    a draft of this preliminary document;

     o    a draft of the merger agreement which Pioneer USA has indicated is
          substantially the form which will be executed in connection with the
          merger of each partnership;


     o    financial statements of each partnership, including, if applicable,
          the partnership's Form 10-Q and Form 10-K, for the three months ended
          March 31, 2001 and for the years ended December 31, 2000, 1999 and
          1998;



     o    the reserve reports prepared by Pioneer Parent and Pioneer USA and the
          review by Williamson Petroleum Consultants, Inc., as of March 31,
          2001, relating to the reserves of each partnership;



     o    calculations prepared by Pioneer Parent and Pioneer USA of the merger
          value per $1,000 of limited partner investment in each partnership;


     o    Pioneer USA's analysis of other alternatives to the merger of each
          partnership, including going concern value, liquidation value, royalty
          trust and production payment;


     o    estimates prepared by Pioneer Parent and Pioneer USA of the merger
          value, going concern value and liquidation value per $1,000 of limited
          partner investment in each partnership;



     o    the financial statements of Pioneer Parent included in its Form 10-Q
          for the three months ended March 31, 2001 and its Form 10-K for the
          years ended December 31, 2000, 1999 and 1998;



     o    pro forma financial data for Pioneer Parent assuming the completion of
          the proposed merger transaction; and



     o    recent trading activity in shares of Pioneer Parent common stock.



                                      -34-
   45



     In the course of its analysis, Stanger conducted interviews of senior
management personnel of Pioneer USA. During such interviews, Stanger and the
senior management personnel reviewed the status of the merger of each
partnership, the reserve pricing and related value estimates, the estimated
timing of the merger of each partnership and other matters.


     Stanger reviewed estimates of the merger value, going-concern value, and
liquidation value prepared by Pioneer USA with respect to each partnership. In
addition, Stanger reviewed secondary market prices, as tracked by Stanger, for
limited partnership interests in each partnership along with tender offers
received by limited partners as derived from data provided by Pioneer USA.
Stanger's analysis is summarized below.


     Review of Merger Value for Each Partnership. Stanger reviewed the
calculation of the merger value for each partnership prepared by Pioneer USA.
Stanger observed that such calculation includes the reserve value, as described
below, and other current assets as of March 31, 2001, as reduced by other
current liabilities as of March 31, 2001, less the partnership's pro rata share,
based on its reserve value, of the estimated expenses and fees of the mergers of
all of the partnerships and less the cash distribution to be mailed on or about
July 12, 2001, by the partnership to its partners. Stanger reviewed the balance
sheet of each partnership as of March 31, 2001 as prepared by Pioneer USA, and
reconciled the current assets and current liabilities on such financial
statements to the balances included in the merger value calculation for each
partnership.



     Stanger reviewed the summary reserve reports for each partnership prepared
by Pioneer Parent and Pioneer USA as reviewed by Williamson Petroleum
Consultants, Inc. as of March 31, 2001. Stanger noted that the summary reserve
report was prepared based upon the following pricing case: (1) a five-year NYMEX
futures price for oil and gas as of March 30, 2001, with prices held constant
after year five at the year five price and (2) historical operating costs
adjusted only for those items affected by commodity prices, such as production
taxes and ad valorem taxes. For 2001, the oil and gas prices were based on the
average NYMEX futures price for the nine-month period beginning on April 1, 2001
and ending December 31, 2001. The standard industry adjustments reflect oil
quality, BTU content, oil and gas gathering and transportation costs, and gas
processing costs and shrinkage.



     Stanger further observed that the summary reserve report utilized a
discount rate of 10.0% and resulted in a per barrel of oil equivalent, or BOE,
value of the reserves for each of the partnerships ranging from $3.53 to $4.61.
Stanger observed that such BOE values are low by general industry averages.
However, Stanger observed that such properties are long-lived, generally
low-volume properties, not operated by any of the partnerships, and are subject
to overhead charges by the operator, Pioneer USA. In the course of its
engagement, Stanger reviewed selected comparable transactions in the BOE value
range described above for long-lived, generally low-volume properties. Such
transactions, including some transactions involving other Pioneer USA
affiliates, provided a range of value per BOE of $2.97 to 5.08 and an average of
$4.00.



     Stanger, in connection with its engagement, interviewed acquisitions
personnel at seven oil and gas companies regarding targeted pricing case ranges
and discount rate ranges in order to assess the reasonableness of the pricing
case and discount rates utilized to establish the reserve value for the
partnerships. With respect to the pricing case ranges, Stanger observed a low
pricing case range pursuant to the survey of $22 per barrel of oil and $3.50 per
Mcf of gas, held flat for the life of the reserves to a high pricing case range
of NYMEX strip pricing (plus $2 per barrel of oil) and NYMEX strip pricing for
gas, held flat after five years for the life of the reserves. With respect to
discount rates, Stanger observed a range of discount rates from a low of 9% to
13% applied generally to a low range pricing case to a high range of 15% to 20%,
applied generally to a high range pricing case. Stanger concluded that the
pricing case and discount rates utilized to establish the merger value for each
partnership fall within the ranges established in interviews with acquisition
professionals.


     Going Concern Value. Stanger reviewed the going concern value calculation
prepared for each partnership by Pioneer USA. The going concern value was based
upon:


     o    The sum of (1) the estimated net cash flow from sale of the reserves
          during a 10-year operating period and (2) the estimated residual value
          from the sale of the remaining reserves at the end of the operating
          period, in each case using the same pricing and discount rate as in
          the merger value calculation; less


     o    Partnership level general and administrative expenses, calculated as
          follows and, consistent with the calculation of 2000 and 1999
          expenses, generally representing the maximum expense percentages
          permitted under the partnership agreements:

          -    The partnership agreement for each of Parker & Parsley 81-I,
               Ltd., Parker & Parsley 81-II, Ltd., Parker & Parsley 82-I, Ltd.,
               Parker & Parsley 82-II, Ltd. and Parker & Parsley 82-III, Ltd.
               permits Pioneer USA to allocate to the partnership (1) general
               and administrative expenses and (2) all expenses directly
               attributable to the partnership as a result of fees or charges by
               parties other than Pioneer USA or its affiliates, including
               legal, auditing and engineering fees. However, for purposes of
               clause (1) and for administrative ease and to the benefit of each
               of those partnerships, Pioneer USA allocates to each of those
               partnerships general and administrative expenses based on 3% of
               the revenues of the partnership.


                                      -35-
   46



          -    The partnership agreement for each of Parker & Parsley 83-A, Ltd.
               and Parker & Parsley 83-B, Ltd. permits Pioneer USA to allocate
               to the partnership (1) general and administrative expenses in an
               annual amount not to exceed the sum of 2% of the initial partner
               capital for the partnership and 2.25% of the drilling and
               completion expenses, of which there are none, and (2) all
               expenses directly attributable to the partnership as a result of
               fees or charges by parties other than Pioneer USA or its
               affiliates, including legal, auditing and engineering fees.
               However, for purposes of clause (1) and for administrative ease
               and to the benefit of each of those partnerships, Pioneer USA
               allocates to each of those partnerships general and
               administrative expenses based on 3% of the revenues of the
               partnership.



          -    The partnership agreement for Parker & Parsley 84-A, Ltd. permits
               Pioneer USA to allocate to the partnership (1) general and
               administrative expenses in an annual amount not to exceed the sum
               of 3.25% of the revenues of the partnership and 2.25% of the
               drilling and completion expenses, of which there are none, and
               (2) all expenses directly attributable to the partnership as a
               result of fees or charges by parties other than Pioneer USA or
               its affiliates, including legal, auditing and engineering fees.
               However, for purposes of clause (1) and for administrative ease
               and to the benefit of the partnership, Pioneer USA allocates to
               the partnership general and administrative expenses based on 3%
               of the revenues of the partnership.


          -    The partnership agreement for each of the following partnerships
               permits Pioneer USA to allocate to the partnership general and
               administrative expenses, including all expenses directly
               attributable to the partnership as a result of fees or charges by
               parties other than Pioneer USA or its affiliates, such as legal,
               auditing and engineering fees, in an annual amount not to exceed
               2% of the revenues of the partnership.

                  Parker & Parsley Private Investment 85-A, Ltd.
                  Parker & Parsley Selected 85 Private Investment, Ltd.
                  Parker & Parsley Private Investment 86, Ltd.

          -    The partnership agreement for each of the following partnerships
               permits Pioneer USA to allocate to the partnership general and
               administrative expenses, including all expenses directly
               attributable to the partnership as a result of fees or charges by
               parties other than Pioneer USA or its affiliates, such as legal,
               auditing and engineering fees, in an annual amount not to exceed
               3% of the revenues of the partnership.

                  Parker & Parsley 85-A, Ltd.
                  Parker & Parsley 85-B, Ltd.
                  Parker & Parsley 86-A, Ltd.
                  Parker & Parsley 86-B, Ltd.
                  Parker & Parsley 86-C, Ltd.
                  Parker & Parsley 87-A Conv., Ltd.
                  Parker & Parsley 87-A, Ltd.
                  Parker & Parsley 87-B Conv., Ltd.
                  Parker & Parsley 87-B, Ltd.
                  Parker & Parsley Producing Properties 87-A, Ltd.
                  Parker & Parsley Producing Properties 87-B, Ltd.
                  Parker & Parsley Private Investment 87, Ltd.
                  Parker & Parsley 88-A Conv., L.P.
                  Parker & Parsley 88-A, L.P.
                  Parker & Parsley 88-B Conv., L.P.
                  Parker & Parsley 88-B, L.P.
                  Parker & Parsley 88-C Conv., L.P.
                  Parker & Parsley 88-C, L.P.
                  Parker & Parsley Producing Properties 88-A, L.P.
                  Parker & Parsley Private Investment 88, L.P.

          -    The partnership agreement for each of the following partnerships
               permits Pioneer USA to allocate to the partnership (1) general
               and administrative expenses in an annual amount not to exceed 3%
               of the revenues of the partnership, and (2) all expenses directly
               attributable to the partnership as a result of fees or charges by
               parties other than Pioneer USA or its affiliates, including
               legal, auditing and engineering fees.

                  Parker & Parsley 89-A Conv., L.P.
                  Parker & Parsley 89-A, L.P.
                  Parker & Parsley 89-B Conv., L.P.
                  Parker & Parsley 89-B, L.P.


                                      -36-
   47


                  Parker & Parsley 90-A Conv., L.P.
                  Parker & Parsley 90-A, L.P.
                  Parker & Parsley 90-B Conv., L.P.
                  Parker & Parsley 90-B, L.P.
                  Parker & Parsley 90-C Conv., L.P.
                  Parker & Parsley 90-C, L.P.
                  Parker & Parsley 91-A, L.P.
                  Parker & Parsley 91-B, L.P.

          -    The partnership agreement for each of the following partnerships
               permits Pioneer USA to allocate to the partnership (1) general
               and administrative expenses in an annual amount not to exceed 5%
               of the revenues of the partnership, and (2) all expenses directly
               attributable to the partnership as a result of fees or charges by
               parties other than Pioneer USA or its affiliates, including
               legal, auditing and engineering fees. However, for purposes of
               clause (1) and for administrative ease and to the benefit of each
               of the partnerships, Pioneer USA allocates to the partnership
               general and administrative expenses based on 3% of the revenues
               of the partnership.

                  Parker & Parsley Private Investment 89, L.P.
                  Parker & Parsley Private Investment 90, L.P.
                  Parker & Parsley 90 Spraberry Private Development, L.P.


     Stanger observed that the going concern value of each partnership was
adjusted for the March 31, 2001 working capital balance less the distribution to
be mailed on or about July 12, 2001 and that such going concern value ranged
from 4.6% to 10.0% less than the merger value for each partnership. See the
supplemental information table on the second page of the supplement for each
partnership for its merger value and its going concern value, in each case per
$1,000 limited partner investment.



     Liquidation Value. Stanger reviewed the liquidation value calculation
prepared for each partnership by Pioneer USA. Such liquidation value was based
upon the sale of the reserves at the reserve value, less liquidation expenses
which are estimated to be the sum of (1) the partnership's pro rata share of the
estimated expenses and fees of the mergers of all of the partnerships and (2) 3%
of the partnership's reserve value. The liquidation expenses represent the
estimated costs to retain an investment banker or broker to sell the assets of
each partnership and the legal and other closing costs associated with such
transaction. Stanger observed that such merger expenses are intended to reflect
Pioneer USA's estimate of the cost associated with brokers' commissions on asset
sales and the additional wind-down costs of the partnership. Stanger observed
that the liquidation value for each partnership ranged from 2.7% to 3.0% less
than the merger value for each partnership. See the supplemental information
table on the second page of the supplement for each partnership for its merger
value and its liquidation value, in each case per $1,000 limited partner
investment.



     Secondary Market Prices. To determine the most up-to-date secondary market
prices, Stanger reviewed the secondary market prices for units of limited
partnership interests in each of the partnerships during the 12 months ended
April 30, 2001, collected from data maintained on partnerships by Stanger.
Stanger observed that secondary market transactions were reported for 25 of the
partnerships during such period. Stanger observed that for all partnerships
except Parker & Parsley 81-II, Ltd. and Parker & Parsley Producing Properties
87-A, Ltd., the weighted average secondary market price on a per $1,000 original
investment basis was less than the merger value per $1,000 original investment.
For such other partnerships, the range of discount to the merger value per
$1,000 investment was 5.2% to 52.7%, averaging 27.7%. For Parker & Parsley
81-II, Ltd., Stanger observed that only one transaction involving $35,000 of
original investment (7 units) was at a price in excess of the merger value. For
Parker & Parsley Producing Properties 87-A, Ltd., Stanger observed that only one
transaction involving $10,000 of original investment (20 units) was at a price
in excess of the merger value per $1,000 of original investment. All other
secondary market transactions for Parker & Parsley Producing Properties 87-A,
Ltd. were reported at prices below the merger value. Stanger also observed
secondary market transactions at prices in excess of the merger value for one
additional partnership. Secondary market firms reported a single transaction
during the twelve months ended April 30, 2001 for Parker & Parsley 82-II, Ltd.
at a price in excess of merger value. All other transactions reported for such
partnerships were at amounts less than the merger value during the twelve months
ended April 30, 2001.


     Stanger also reviewed the secondary market data obtained by Pioneer USA
from Partnership Spectrum and included in Table 15 of Appendix A to this
document. Stanger observed that such data included partnerships which reported a
secondary market transaction price in excess of the high-end transaction price
Stanger observed in its data. In all cases, such high-end range was lower than
the merger value.


     Prices in the secondary market are based on market prices at the time of
the secondary market transaction, which prices may be lower than prices
prevailing at March 30, 2001 or as of the date of mailing this document.



     Selected Tender Offers. Stanger observed that Pioneer USA reported
unsolicited tender offers from unaffiliated third parties for less than 5% of
the interests in the following partnerships during the period June 1998 through
June



                                      -37-
   48


2001. Stanger observed that the tender offers and related merger value per
limited partnership interest for each of those partnerships were as follows:





                                                        MERGER VALUE            TENDER OFFER                DISCOUNT TO
                   PARTNERSHIP                   (PER $1,000 INVESTMENT)   (PER $1,000 INVESTMENT)         MERGER VALUE
                   -----------                   -----------------------   -----------------------    --------------------
                                                                                              
Parker & Parsley 82-II, Ltd.                             $101.61                    $13.75                   (86.5%)
Parker & Parsley 82-III, Ltd.                             121.72                     26.25                   (78.4%)
Parker & Parsley 83-A, Ltd.(a)                            141.43                40.00 to 70.00          (50.5%) to (71.7%)
Parker & Parsley 83-B, Ltd.(a)                            154.41                50.00 to 55.00          (64.4%) to (67.6%)
Parker & Parsley 84-A, Ltd.                               201.43                     60.00                   (70.2%)
Parker & Parsley 86-A, Ltd.                               177.09                     40.00                   (77.4%)
Parker & Parsley 86-B, Ltd.                               224.17                    115.00                   (48.7%)
Parker & Parsley 86-C, Ltd.(a)                            161.23                65.00 to 67.50          (58.1%) to (63.7%)
Parker & Parsley 87-A, Ltd.(a)                            190.81                90.00 to 105.00         (45.0%) to (52.8%)
Parker & Parsley 87-B, Ltd.(a)                            201.38                60.00 to 65.00          (67.7%) to (70.2%)
Parker & Parsley 88-A, L.P.                               245.95                     80.00                   (67.5%)
Parker & Parsley 88-B, L.P.                               321.02                     50.00                   (84.4%)
Parker & Parsley Private Investment 89, L.P.              270.69                    162.50                   (40.0%)
Parker & Parsley 90-B, L.P.(a)                            265.39               102.50 to 160.00         (39.7%) to (61.4%)
Parker & Parsley 90-C, L.P.(a)                            243.26                30.00 to 40.00          (83.6%) to (87.7%)
Parker & Parsley 90 Spraberry Private Dev., L.P.          288.51                    162.50                   (43.7%)



---------
(a)  More than one tender offer for partnership interests was made. Amounts
     shown represent the range of tender offer prices.


     Stanger observed that the above tender offers represent a discount to the
merger value for each of those partnerships of 39.7% to 87.7%. Stanger also
observed that tender offers for limited partnership securities are generally at
prices which represent a substantial discount to the underlying value of the
assets held by such partnerships. Furthermore, the tender offer prices are based
on oil prices prevailing at the time of the tender offer, which prices may have
been lower than oil prices prevailing at March 30, 2001 or as of the date of
mailing this document.


     Repurchase Offers. Stanger observed that for each of the six partnerships
listed below, which Stanger calls the repurchase partnerships, Pioneer USA is
required under the partnership agreement for the partnership to offer to
repurchase units of limited partnership interests in the partnership annually at
a formula price based upon the December 31 year end reserve report. Stanger
observed that the repurchase offer pricing at December 31, 2000 tends to
overstate the value of units of the repurchase partnerships due primarily to the
oil and gas prices in effect on such date and the effect of such pricing on the
cash flows and recoverable reserves. Stanger observed that the repurchase offers
for 2000 for the repurchase partnerships are at premiums to the merger value
ranging from 25.5% to 68.5% as follows:




                                         PER $1,000 ORIGINAL INVESTMENT
                                   -----------------------------------------
                                   MERGER VALUE   REPURCHASE OFFER   PREMIUM
                                   ------------   ----------------   -------
                                                           
Parker & Parsley 82-I, Ltd.          $ 80.06        $137.97           72.3%
Parker & Parsley 82-II, Ltd.          101.61         133.72           31.6%
Parker & Parsley 82-III, Ltd.         121.72         150.59           23.7%
Parker & Parsley 83-A, Ltd.           141.43         196.67           39.1%
Parker & Parsley 83-B, Ltd.           154.41         210.15           36.1%
Parker & Parsley 84-A, Ltd.           201.43         267.03           32.6%





     Stanger observed that the repurchase rights may be exercised only once a
year and that a limited partner may exercise its repurchase right by delivering
a written request to Pioneer USA no later than March 31 of each year. Pioneer
USA advised Stanger that on or before May 31 of each year, Pioneer USA must
notify each limited partner who has exercised its repurchase right of the amount
of limited partnership interests to be repurchased and the method of calculating
the repurchase price. Pioneer USA advised Stanger that the aggregate amount of
limited partnership interests required to be repurchased in any one year is
limited to $100,000 per partnership. A repurchase price is calculated by
multiplying:



                                      -38-
   49



     o    the present value of the estimated future net revenues, calculated
          using a discount rate equal to prime plus 1% as of December 31 of each
          year, from a partnership's estimated reserves, as determined by
          independent petroleum consultants; by



     o    66 2/3%.



Stanger advised that each limited partner who has exercised its repurchase right
has 60 days to accept Pioneer USA's repurchase offer and that Pioneer USA must
pay the repurchase price to each limited partner who accepts the repurchase
offer within 30 days after acceptance.



     Stanger further advised Pioneer USA and each repurchase partnership that no
adjustment was made to the merger value offered to the repurchase partnership to
reflect the repurchase offer obligation and Stanger's opinion does not include
an opinion as to the fairness of the termination of Pioneer USA's repurchase
obligation.



     Assumptions. Pioneer Parent and Pioneer USA advised Stanger that the oil
and gas properties owned by each partnership are subject to operating agreements
with Pioneer USA and that:


     o    such operating agreements provide for the payment of overhead charges
          and that such charges are reasonable compared with amounts charged for
          similar services by third party operators;

     o    except for cause, such operating agreements do not provide for the
          termination of Pioneer USA as operator; and

     o    such operating agreements do not provide for the revision of the
          overhead charges, except as escalated under the terms of such
          operating agreements.


Furthermore, Pioneer Parent and Pioneer USA advised Stanger that if each
partnership's reserves were offered for sale to a third party, a condition of
such sale would be that the oil and gas reserves would continue to be subject to
the operating agreements with Pioneer USA which provide for the payment of
overhead charges, and that it would be appropriate to assume, when estimating
the value of such reserves, that such charges would continue.



     In addition, Pioneer Parent and Pioneer USA advised Stanger that the
reserve value and working capital balance of each partnership has been properly
allocated between the general partners and the limited partners of each
partnership in accordance with the partnership agreement with respect to a
liquidation.



     Stanger did not conduct any engineering studies and has relied on estimates
of Pioneer Parent and Pioneer USA with respect to oil and gas reserve volumes,
prices, operating costs and overhead charges with respect to the reserve value
estimates. Furthermore, Stanger has relied upon the review by Williamson of the
summary reserve reports as of March 31, 2001.



     Stanger also relied on the assurance of Pioneer Parent, Pioneer USA and
each partnership that:



     o    the summary reserve report reviewed by Williamson Petroleum
          Consultants, Inc. as of March 31, 2001, and provided to Stanger was in
          the judgment of Pioneer USA and each partnership reasonably prepared
          on bases consistent with actual historical experience and reflect
          their best currently available estimates and good faith judgments;


     o    there are no estimates of costs to remediate environmental conditions
          included in the reserve analysis;

     o    any historical financial data, balance sheet data, merger value
          analyses, going concern value analyses and liquidation value analyses
          are accurate and complete in all material respects;

     o    all allocations included in the calculations of merger values, going
          concern values and liquidation values have been made in accordance
          with the partnership agreement of each partnership;

     o    no material changes have occurred in the information reviewed or in
          the value of the oil and gas reserves or working capital balances of
          each partnership between the date the information was provided to
          Stanger and the date of Stanger's opinion;

     o    the relative ownership interests of (1) the limited partners of each
          partnership, (2) the unaffiliated limited partners of each
          partnership, (3) the general partners of each partnership, (4) the
          unaffiliated limited partners of the nonmanaging general partner, if
          any, of each partnership and (5) Pioneer USA, as the managing or sole
          general partner of each partnership, is accurately included in
          accordance with the partnership agreement for each partnership in the
          analyses provided to Stanger by Pioneer USA;


                                      -39-
   50

     o    neither Pioneer Parent or any of its affiliates has during the thirty
          days prior to the date hereof commenced or continued a share
          repurchase program or similar transaction which could affect the price
          of shares of Pioneer Parent common stock to be used in the proposed
          merger transaction; and




     o    Pioneer Parent, Pioneer USA and each partnership are not aware of any
          information or facts regarding the partnership, the oil and gas
          properties, the reserve analysis or the working capital balances of
          the partnership that would cause the information supplied to Stanger
          to be incomplete or misleading in any material respect.


     Stanger's opinion is based upon business, economic, oil and gas market and
other conditions as of the date of its analysis and addresses the merger value
for each partnership in the context of information available as of the date of
Stanger's analysis. Events occurring after the date of Stanger's analysis could
affect the value of the assets of each partnership or the assumptions used in
the preparation of Stanger's fairness opinion.

     Conclusions. Stanger concluded that, based upon and subject to its
analysis, assumptions, limitations and qualifications cited in its opinion, and
as of the date of the fairness opinion, the merger value for each partnership
and the allocation of the merger value of the partnership (1) to the limited
partners of the partnership as a group, (2) to the general partners of the
partnership as a group, (3) to Pioneer USA as the managing or sole general
partner of the partnership, (4) to the unaffiliated limited partners of the
partnership as a group and (5) to the unaffiliated limited partners of the
nonmanaging general partner, if any, of the partnership as a group, is fair to
the unaffiliated limited partners of the partnership and the unaffiliated
limited partners of the nonmanaging general partner, if any, of the partnership,
from a financial point of view.

     Compensation and Material Relationships. Stanger has been paid a total fee
of $350,000 in connection with the rendering of the fairness opinion. Such fee
was not conditioned on Stanger's findings and is payable whether or not the
merger of each partnership is consummated. In addition, Stanger will be
reimbursed for all reasonable out-of-pocket expenses, including legal fees, and
will be indemnified against some liabilities, including some liabilities under
the securities laws. To the extent that such indemnification includes
liabilities arising under the federal securities laws, it may not be enforceable
as it may be determined to be against public policy.

     During the past two years, Pioneer USA engaged Stanger to render financial
advisory services in connection with proposed transactions which were withdrawn
and never consummated. In connection with such assignments Stanger was paid fees
aggregating $175,000.

SUMMARY RESERVE REPORT


     Pioneer USA engaged Williamson Petroleum Consultants, Inc., an independent
petroleum engineering consulting firm based in Midland, Texas, to review a
summary reserve report of the property interests of each of the partnerships as
of March 31, 2001. THE FULL TEXT OF THE REVIEW OF THE SUMMARY RESERVE REPORT BY
WILLIAMSON PETROLEUM CONSULTANTS, INC. EFFECTIVE AS OF MARCH 31, 2001, IS
ATTACHED AS APPENDIX B. WE ENCOURAGE YOU TO READ IT CAREFULLY IN ITS ENTIRETY.


     Qualifications and Method of Selection. Williamson is engaged solely in the
business of petroleum evaluation and engineering studies for public and private
oil and gas companies. Williamson is widely recognized in its field. Williamson
is an independent consulting firm as provided in the Standards Pertaining to the
Estimating and Auditing of Oil and Gas Reserves Information promulgated by the
Society of Petroleum Engineers.

     Pioneer USA engaged Williamson based upon Pioneer USA's assessment of their
professional reputations and qualifications, capabilities, experience and
responsiveness. In addition, Williamson is the independent petroleum engineering
firm most familiar with the properties in which each partnership has interests
and has prepared the annual independent reserve report for each partnership's
reserves since the inception of each partnership.


     Summary of Procedures, Scope and Findings. Williamson reviewed the
calculations of the estimated total net estimated reserves for each partnership
and the present value of the estimated future net revenues from the estimated
reserves for each partnership as of March 31, 2001, based on the following
parameters provided by Pioneer USA: (1) a five-year NYMEX futures price for oil
and gas as of March 30, 2001 with prices held constant after year five at the
year five price, less standard industry adjustments, (2) historical operating
costs adjusted only for those items affected by commodity prices, such as
production taxes and ad valorem taxes, and (3) a 10.0% discount rate. For 2001,
the oil and gas prices were based on the average NYMEX futures price for the
nine-month period beginning on April 1, 2001 and ending December 31, 2001.
Williamson's estimated total net estimated reserves and the present value of the
estimated future net revenues from the estimated reserves for each partnership
are set forth in the exhibits to the summary reserve report attached as Appendix
B to this document.



     Pioneer Parent determined the amount of Pioneer Parent common stock to be
offered. Williamson did not opine on the fairness of the transaction.



                                      -40-
   51



     In preparing its summary reserve report, Williamson assumed the accuracy
and completeness of all information provided by Pioneer USA or information which
was publicly available and did not attempt to independently verify such
information. Williamson did not make field inspections or judgments relative to
environmental or other legal liabilities. Except as described in this document,
Pioneer USA did not instruct Williamson as to the pricing, cost or other
economic parameters or methods or the assessment of reserves characteristics,
nor did it limit the scope of Williamson's investigation for purposes of
preparing its summary reserve report.


     Pioneer USA provided Williamson with all evaluation data with respect to
interests, reversionary status, oil and gas prices, gas categories, gas contract
terms, operating expenses, investments, salvage values, abandonment costs, net
profit interests, well information and current operating conditions for
Williamson's use in determining each partnership's reserves. Williamson used
production data provided by Pioneer USA, and where information was not provided
by Pioneer USA, Williamson used production data from public records. Williamson
prepared its own reserve estimates of the property interests.

     Prior Material Relationships. Williamson has estimated total proved
reserves and the present value of estimated future revenues from those reserves
for each of the partnerships since their respective inceptions. In addition,
Pioneer USA engaged Williamson to prepare a summary reserve report in connection
with a proposed transaction in 1999, similar to the one described in this
document, which was withdrawn and never consummated. Pioneer USA and its
affiliates have paid $112,700 over the past two years to Williamson. Neither
Williamson nor any of its personnel has any direct or indirect interest in
Pioneer USA or any of the partnerships, and Williamson's compensation is not
contingent upon the results of its summary reserve report.

ALTERNATIVE TRANSACTIONS TO THE MERGER OF EACH PARTNERSHIP

     We considered the following alternative types of transactions before
selecting the merger transaction described in this document. As discussed below,
we believe that the merger of each partnership is the best available alternative
for each partnership to maximize the consideration to the limited partners.

     Comparison of the Merger of Each Partnership to Continuing Operations.
Because each partnership's properties are mature, producing properties, we
believe that production from those properties will continue to decline at the
rate predicted in the partnership's oil and gas engineering reserve reports.
Accordingly, cash distributions from each partnership will also decline, subject
to variation for changes in oil and gas prices. The marginal benefit of
continuing operations of each partnership is offset by the general and
administrative costs related to continuing operations. See "Special Factors --
Reasons for the Merger of Each Partnership" beginning on page 29 of this
document.


     We also believe there is a substantial advantage in receiving the
liquidating distribution at present in the form of Pioneer Parent common stock,
rather than continuing to receive decreasing levels of cash distributions over a
long period of time. We believe that the reserve value included in the merger
value for each partnership is higher than the net present value of estimated
future cash distributions to the limited partners from continued operations
because the reserve value has not been reduced for the reimbursement of Pioneer
USA's general and administrative expenses allocable to the partnership. In
addition, although future oil and gas prices could be higher than the prices on
March 30, 2001 which were used in calculating the merger value for each
partnership, continued operations over a long period of time subject the limited
partners of each partnership to the risk of receiving lower levels of cash
distributions if oil and gas prices over this period are lower on average than
those used in preparing the estimates of cash distributions from continued
operations. Continued operations also subject the limited partners of each
partnership to possible changes in costs or need for workover or similar
significant remedial work on each partnership's properties. In contrast, the
Pioneer Parent common stock is a liquid tradeable security which can be sold and
redeployed in other investments. The Pioneer Parent common stock provides the
limited partners of each partnership the opportunity to participate in a larger
entity having more diversified producing reserves and other oil and gas
properties, with the resulting spreading of risks.


     We expect that any nonparticipating partnership will continue operations
and will produce its reserves until depletion with steadily decreasing rates of
cash flow and, as a result, decreasing cash distributions.


     Comparison of the Merger of Each Partnership to Master Limited Partnership.
We considered accomplishing the consolidation of each partnership through a
master limited partnership, pursuant to which the partnership interests of the
limited partners of the partnership would be exchanged for interests in the
master limited partnership. However, we believe each partnership's oil and gas
properties are not of sufficient size, individually or in the aggregate with the
other partnerships, to attract new capital through a master limited partnership.
In addition, the partnership interests in a master limited partnership might not
be traded on a national stock exchange or in any other significant market. Some
master limited partnership interests might be sold from time to time in private
or over-the-counter transactions, but the prices would likely reflect a discount
for illiquidity. As a result, we believe a master limited partnership would not
provide the limited partners with immediate and complete liquidity for their
investment in each partnership. Finally, a master limited partnership would
still be burdened with general and administrative expenses, which would reduce
any cash distributions paid to the partners of the master limited



                                      -41-
   52


partnership. The merger value for each partnership reflects a liquidation value
and has not been reduced for any reimbursement of Pioneer USA's general and
administrative expenses allocable to the partnership.


     Comparison of the Merger of Each Partnership to Royalty Trust. We also
considered a royalty trust, pursuant to which the partnership interests of each
partnership would be exchanged for beneficial ownership interests in the trust.
Like the master limited partnership alternative discussed above, we believe each
partnership's oil and gas properties are not of sufficient size, individually or
in the aggregate with the other partnerships, to attract new capital through a
royalty trust. In addition, the beneficial ownership interests in a royalty
trust might not be publicly traded in a significant market. As a result, this
alternative was not selected because we believe it would not result in immediate
and complete liquidity for the limited partners' investments in any partnership.
Finally, a royalty trust would still be burdened with general and administrative
expenses, which would reduce any cash distributions paid to the beneficiaries of
the royalty trust. The merger value for each partnership reflects a liquidation
value and has not been reduced for any reimbursement of Pioneer USA's general
and administrative expenses allocable to the partnership.



     Comparison of the Merger of Each Partnership to Production Payment. We also
considered whether each partnership would benefit from attempting to sell a
production payment against its future oil and gas production in exchange for
cash. Like the master limited partnership and royalty trust alternatives
discussed above, we believe each partnership's oil and gas properties are not of
a sufficient size, individually or in the aggregate with the other partnerships,
to attract new capital from lenders or investors. In addition, lenders or
investors that provide production payment alternatives will not advance funds
against 100% of future oil and gas production, and typically limit any
production payment transaction to less than 70% of estimated future oil and gas
production. As a result, this alternative was not selected because we believe it
would not provide the limited partners with immediate and complete liquidity for
their investment in each partnership. Even with a production payment
transaction, each partnership would continue to be burdened with general and
administrative expenses which would reduce any cash distributions paid to the
limited partners. The merger value for each partnership reflects a liquidation
value and has not been reduced for any reimbursement of Pioneer USA's general
and administrative expenses allocable to the partnership.



     Comparison of the Merger of Each Partnership to Negotiated Sale. We also
considered whether each partnership would benefit from attempting to sell its
property interests in negotiated transactions. Buyers would be purchasing the
partnership's property interests which they would neither control nor operate. A
portion of the properties in which each partnership owns interests would
continue to be operated by Pioneer USA because Pioneer USA controls other
interests in fields in which the partnership's properties are located. Because
of Pioneer USA's control of such properties, Pioneer Parent and Pioneer USA
believe Pioneer Parent is the party in the position to pay the highest price for
such interests and the one most likely to do so. In contrast, Pioneer USA's
control of such properties could negatively affect the amount a third party is
willing to pay and the overall interest of third parties in buying such
properties.



     In addition, sale of each partnership's properties on a direct basis often
involves substantial periods of time for due diligence, negotiation and
execution of agreements and closings, often with different purchasers for
different properties. Satisfying due diligence requests requires large amounts
of time to create and supervise data rooms or disseminate data to possible
purchasers, plus the time needed to deal directly with multiple prospective
purchasers. Furthermore, some issues, such as environmental and title matters,
may come to light in the late stages of a negotiated sale, which may delay or
preclude the consummation of the sale.


     The transaction costs for offering properties in a negotiated sale could be
substantial, and often are higher than other means of sale. Those costs include:

     o    preparing and disseminating information on properties to be offered;

     o    soliciting attendance by prospective purchasers; and

     o    screening and qualifying purchasers.


     In a third party sale, we expect that each partnership would have to pay
its own expenses or that the price would be reduced to take the expenses into
account.



     Although we believe the factors described above to be true, we are
conducting a limited form of auction. That is, in September 1999 we established
a price and publicly announced that we will consider third party offers to
purchase any partnership or its assets at prices that are higher than the 1999
merger value for such partnership. We have repeated our willingness to consider
third party offers in connection with the merger of each partnership we now
propose, so long as the prices offered exceed those we are offering. We believe
this process would result in a better price to the limited partners than if we
merely offered the partnership or its assets for sale at any price. Pioneer
Parent has the right to match or top any third party offer. In addition, any
such offer would be subject to our right to continue operation of the
properties. See "The Merger of Each Partnership -- Third Party Offers" on page
52.


                                      -42-
   53


Although we received some preliminary indications of interest from third parties
during the last quarter of 1999, none of those third parties has ever made a
formal bid for any partnership or its assets.

                           FORWARD-LOOKING STATEMENTS


     This document includes "forward looking statements" as defined by the
Securities and Exchange Commission. These statements concern Pioneer Parent's,
Pioneer USA's and each partnership's plans, expectations and objectives for
future operations. All statements, other than statements of historical facts,
included in this document that address activities, events or developments that
Pioneer Parent, Pioneer USA and each partnership expect, believe or anticipate
will or may occur in the future are forward looking statements and include the
following:


     o    completion of the proposed merger of each partnership;

     o    reserve estimates;

     o    future production of oil and gas; and

     o    future financial performance.


     These forward looking statements are based on assumptions, which Pioneer
Parent, Pioneer USA and each partnership believe are reasonable, but which are
open to a wide range of uncertainties and business risks. Factors that could
cause actual results to differ materially from those anticipated are discussed
in (1) "Risk Factors" beginning on page 17 of this document, (2) periodic
filings with the Securities and Exchange Commission, including Annual Reports on
Form 10-K for the year ended December 31, 2000, for Pioneer Parent and each
reporting partnership, and (3) "Management's Discussion and Analysis of
Financial Condition and Results of Operations" for the year ended December 31,
2000 included in the supplement to this document for each nonreporting
partnership.


     "Safe Harbor" Statement under the Private Securities Litigation Reform Act
of 1995: Statements in this document regarding each company's business which are
not historical facts are "forward looking statements" that involve risks and
uncertainties. For a discussion of these risks and uncertainties, which could
cause actual results to differ from those contained in the forward looking
statements, see "Risk Factors" beginning on page 17 of this document.


                                      -43-
   54



             METHOD OF DETERMINING MERGER VALUE FOR EACH PARTNERSHIP
                AND AMOUNT OF PIONEER PARENT COMMON STOCK OFFERED



     Pioneer Parent and Pioneer USA agreed to a merger value for each
partnership for purposes of the merger of the partnership. The method of
determining the merger value for each partnership was not determined by
arm's-length negotiations. See "Risk Factors -- You Were Not Independently
Represented in Establishing the Terms of the Merger of Each Partnership" on page
17 and "Interests of Pioneer Parent, Pioneer USA and Their Directors and
Officers" on page 63.



     In March 2001, Pioneer Parent and Pioneer USA agreed to use March 31, 2001
to determine the merger value for each partnership and to base the number of
shares of Pioneer Parent common stock to be offered on the average closing price
of the Pioneer Parent common stock, as reported by the New York Stock Exchange,
for the ten trading days ending three business days before the initial date of
the special meeting for each partnership. For purposes of illustration in this
document, we have calculated the number of shares to be issued based on an
assumed average closing price of $18.00 per share of Pioneer Parent common
stock. Prior to the date of the special meeting for each partnership, we will
update the number of shares to be issued using the actual average closing price
of Pioneer Parent common stock for the ten trading days ending three business
days before the initial date of the special meeting. Neither Pioneer Parent nor
Pioneer USA will adjust any of the other components of the merger value for any
partnership.


COMPONENTS OF MERGER VALUE FOR EACH PARTNERSHIP


     Pioneer Parent and Pioneer USA calculated the merger value assigned to each
partnership as follows:



     o    Pioneer Parent and Pioneer USA agreed to use the volumes of the
          partnership's estimated reserves as of March 31, 2001, as taken from
          the summary reserve report reviewed by Williamson Petroleum
          Consultants, Inc. as of March 31, 2001.



     o    Pioneer Parent and Pioneer USA agreed to use the present value of
          estimated future net revenues for each partnership from the estimated
          reserves for each partnership at March 31, 2001, as taken from the
          summary reserve report reviewed by Williamson Petroleum Consultants,
          Inc. as of March 31, 2001. The reserve value component of the merger
          value for each partnership is also set forth in Table 16 of Appendix A
          to this document. Pioneer Parent and Pioneer USA instructed Williamson
          to use the following parameters in calculating the present value of
          estimated future net revenues: (1) a five-year NYMEX futures price for
          oil and gas as of March 30, 2001, with prices held constant after year
          five at the year five price, less standard industry adjustments, (2)
          historical operating costs adjusted only for those items affected by
          commodity prices, such as production taxes and ad valorem taxes, and
          (3) a discount rate of 10.0%. For 2001, the oil and gas prices were
          based on the average NYMEX futures price for the nine-month period
          beginning on April 1, 2001 and ending December 31, 2001. See the table
          on page 6 for the NYMEX futures prices. Pioneer Parent and Pioneer USA
          believe that the five-year NYMEX futures prices provide a reasonable
          benchmark on the outlook for energy prices and are regularly used by
          financial markets, industry participants, and lenders in evaluating
          transactions.


          -    The standard industry price adjustments include:

               (1)  the effects of oil quality;

               (2)  British thermal unit, or BTU, content for gas;

               (3)  any bonus paid;

               (4)  oil and gas gathering and transportation costs; and

               (5)  gas processing costs and shrinkage.

               Those adjustments reflect assumptions about the costs to extract,
               transport and process, if necessary, crude oil, natural gas
               liquids and natural gas to their point of sale.


          -    Pioneer Parent and Pioneer USA agreed to use a 10.0% discount
               rate because Pioneer Parent believes that a 10% discount rate is
               necessary based upon the risks involved in the oil and gas
               industry and Pioneer Parent's requirement to achieve a minimum
               rate of return on its investment.



     o    Pioneer Parent and Pioneer USA added the present value of the
          partnership's estimated future net revenues as of March 31, 2001 to
          the partnership's net working capital as of March 31, 2001 and then
          reduced that sum by (i) the partnership's pro rata share, based on its
          reserve value, of the estimated expenses and fees of the mergers of
          all of the partnerships and (2) the cash distribution to be mailed on
          or about July 12, 2001,



                                      -44-
   55



          by the partnership to its partners. Since the merger value for each
          partnership includes net working capital, the merger value assigned to
          the partnership includes the partnership's assets and liabilities
          other than its oil and gas reserves. Each partnership's other assets
          and liabilities consist mainly of cash, accounts receivable from the
          sale of oil and gas production and accounts payable.



     o    The number of shares of Pioneer Parent common stock to be issued to
          the limited partners of each partnership upon the merger of the
          partnership will be determined by dividing the merger value assigned
          to the partnership by the value of one share of Pioneer Parent common
          stock determined as described below. For purposes of example in this
          document, a share of Pioneer Parent common stock has been valued at an
          assumed average closing price of $18.00. However, on the closing date
          of the merger of each partnership, the value of a share of Pioneer
          Parent common stock will be recalculated by computing the average
          closing price of the Pioneer Parent common stock, as reported by the
          New York Stock Exchange, for the ten trading days ending three
          business days before the initial date of the special meeting for each
          partnership. This recalculated value, and not the assumed average
          closing price of $18.00 per share of Pioneer Parent common stock, used
          for illustration purposes in this document and on each limited
          partner's proxy card, will be used to determine the actual number of
          shares of Pioneer Parent common stock to be issued in the merger of
          each partnership. The recalculated value may be more or less than the
          assumed average closing price of $18.00 per share of Pioneer Parent
          common stock. Pioneer Parent may abandon the proposed merger of any or
          all of the partnerships at any time prior to the special meeting for
          any such partnership for any reason including changes in, among other
          things, the price of Pioneer Parent common stock, the market prices
          for oil and gas generally or the oil and gas industry generally.



     Distributions. No cash distributions will be made by any partnership to its
partners after the distribution in July 2001 through the closing date or
termination date of the merger of the partnership. The Pioneer Parent common
stock to be distributed as payment of the merger value of each participating
partnership already reflects the expected amount of those distributions.
However, any cash distributions by a nonparticipating partnership which would
have been paid during that time period in the ordinary course of that
partnership's business will be distributed to its partners at about the same
time that the certificates representing Pioneer Parent common stock are mailed
to the partners of each participating partnership.


     Liabilities. Pioneer USA will assume all of the liabilities, including
contingent liabilities and obligations, of each participating partnership as of
the closing date of the merger of the partnership. As of the date of this
document, Pioneer USA is not aware of any material contingent liabilities to
which any partnership is subject.


     Expenses. The expenses and fees to be incurred in connection with the
merger of each partnership are expected to be approximately $2.0 million in
total. Each participating partnership will pay its pro rata share, based on its
reserve value, of those estimated expenses and fees. Each nonparticipating
partnership will pay a portion of the estimated expenses and fees of the mergers
otherwise allocable to the partnership based on a fraction, the numerator of
which is the percentage of the partnership's limited partnership interests that
are voted in favor of the merger proposals and the denominator of which is the
percentage of the partnership's limited partnership interests for which votes
are cast. Pioneer Parent has agreed to pay (1) the remainder of the estimated
expenses and fees otherwise allocable to such nonparticipating partnership, (2)
any expenses and fees actually incurred in excess of $2.0 million, and (3) if
Pioneer Parent terminates or abandons the merger as to any partnership, any
expenses or fees allocated to that partnership. Pioneer Parent and Pioneer USA
have reduced each partnership's merger value by that partnership's pro rata
share of the estimated expenses and fees.


ALLOCATION OF MERGER VALUE FOR EACH PARTNERSHIP AMONG PARTNERS OF THE
PARTNERSHIP


     In determining the portion of the merger value attributable to each $1,000
of initial limited partner investment in a partnership, Pioneer Parent
determined the amount payable per $1,000 investment as if the assets of the
partnership had been sold on March 31, 2001 for cash equal to the merger value
of the partnership and the proceeds distributed in accordance with the
liquidation provisions of the partnership's partnership agreement. The limited
partners of each participating partnership would receive the same amounts if the
merger value of the partnership was allocated among the partners based on the
revenue-sharing provisions of the partnership agreement except for each of the
following partnerships which will receive more proceeds under the liquidation
provisions of its respective partnership agreement than under its
revenue-sharing provisions due to certain prospect-by-prospect payout provisions
not being met:


                  Parker & Parsley 81-I, Ltd.
                  Parker & Parsley 81-II, Ltd.
                  Parker & Parsley 82-I, Ltd.
                  Parker & Parsley 82-II, Ltd.
                  Parker & Parsley 82-III, Ltd.


                                      -45-
   56


OTHER METHODS OF DETERMINING MERGER VALUES


     Pioneer Parent and Pioneer USA believe that the method used to determine
the merger value for each partnership is a fair and reasonable method of valuing
the partnership's properties. Pioneer Parent and Pioneer USA considered a number
of alternative methods of determining the merger value for each partnership
before selecting a method. However, the selected method might not accurately
reflect the value of each partnership's assets. See "Risk Factors -- Risk
Factors Relating to the Merger of Each Partnership -- The Merger Values for a
Partnership Will Not be Adjusted For Changes in Oil and Gas Prices Before the
Completion of Its Merger" on page 18. The following alternative methods for
determining the merger value for each partnership should be taken into account
in assessing the adequacy of the selected method.



     Book Value of Assets. Pioneer Parent and Pioneer USA did not base the
calculation of merger value for each partnership on the net book value of the
partnership's assets. The net book value of each partnership's assets is based
upon the financial statements reported in accordance with generally accepted
accounting principles. The net book value is not adjusted for estimates in
changes in the fair market value of the assets. For this reason, Pioneer Parent
and Pioneer USA believe that the merger value for each partnership is more
indicative of the fair market value of the assets of each partnership than the
net book value of the partnership's assets. See the supplemental information
table on the second page of the supplement for each partnership for the
partnership's merger value and its book value, in each case per $1,000 limited
partner investment. In all cases except Parker & Parsley 81-II, Ltd., the merger
value is higher than the book value. For Parker & Parsley 81-II, Ltd., the
merger value is lower than book value because of the long-lived nature of the
oil and gas properties owned by Parker & Parsley 81-II, Ltd. The merger value of
Parker & Parsley 81-II, Ltd. takes into account the discounting effect of owning
long-lived oil and gas reserves that is not reflected in a book value
computation for the partnership. Nonetheless, Pioneer USA has determined that
the merger transaction is fair to the limited partners of Parker & Parsley
81-II, Ltd. (1) for the reasons noted above and (2) because Pioneer Parent and
Pioneer USA believe that the five-year NYMEX futures prices used in the
calculation of the merger value for the partnership (A) provide a reasonable
benchmark on the outlook for energy prices, (B) are regularly used by financial
markets, industry participants, and lenders in evaluating transactions, and (C)
are higher than historic prices.



     Trading Price of Units. None of the partnership interests are traded on a
national stock exchange or in any other significant market. Although some
partnership interests are occasionally sold in private or an informal secondary
market for limited partner securities, Pioneer Parent and Pioneer USA believe
any market for the partnership interests is not reliable as an indicator of
value because any such market is highly illiquid and generally reflects an
illiquidity discount. As a result, Pioneer Parent and Pioneer USA did not base
the calculation of the merger value for any partnership on recent trading prices
of partnership interests in the partnership. See Table 15 of Appendix A for
historical information about recent trades of partnership interests in each
partnership.



     Repurchase Offers. Pioneer Parent and Pioneer USA did not base the
calculation of the merger value for any partnership on the price of recent
repurchase offers in the partnership. Most partnerships do not have a repurchase
offer obligation, so no repurchase price information was available for those
partnerships. Of the partnerships with a repurchase offer obligation, the most
recent repurchase offers will be based on December 31, 2000 oil and gas prices.
The merger value for each partnership with repurchase offer obligations is lower
than the 2001 repurchase offer price for the partnership because the repurchase
price was based on NYMEX oil and gas prices as of December 31, 2000, which were
$26.69 per Bbl of oil and $9.95 per Mcf of gas. Pioneer Parent and Pioneer USA
believe that the repurchase obligation is not an indicator of fair value because
it is calculated annually on December 31 using oil and gas prices for that
specific day. The value determined under the repurchase obligation does not
adequately reflect future demand and supply fundamentals which have historically
resulted in significant volatility to oil and gas prices. See "Risk Factors --
Risk Factors Relating to the Merger of Each Partnership -- Repurchase Offers in
2001 By Each of the Six Partnerships with a Repurchase Obligation were Higher
than the Merger Value for the Partnership" on page 19 of this document and Table
8 of Appendix A to this document for information on each partnership with
repurchase offer obligations.



     Timing of Pricing. Oil and gas prices have recovered from NYMEX oil and gas
prices of $12.00 per Bbl of oil and $2.00 per Mcf of gas as of December 31,
1998, to the five-year NYMEX futures prices for oil and gas as of March 30,
2001, set forth in the table on page 6 of this document. Pioneer Parent and
Pioneer USA used those recovered oil and gas prices to calculate the merger
value for each partnership. Future oil and gas prices could be higher or lower
than the prices on March 30, 2001 which were used in calculating the merger
value for each partnership. Significant increases in future prices would
increase cash available for distribution from each partnership and could, in
retrospect, suggest that the merger value for such partnership was low by
comparison. If those current prices were to continue to prevail in the future,
the merger value for each partnership would appear low by comparison. In
contrast, however, if those current prices decline in the future, the merger
value for each partnership would appear high by comparison.



                                      -46-
   57

                         THE MERGER OF EACH PARTNERSHIP

GENERAL


     Immediately before the effective time of the merger of each participating
partnership, the partnership agreement for the partnership will be amended by
the merger amendment to permit the merger of the partnership with and into us.
At the effective time of the merger of each participating partnership, the
partnership will be merged with and into us. We will be the surviving entity. In
addition, at the effective time of the merger of each participating partnership,
each of your partnership interests in the partnership will be converted into the
right to receive Pioneer Parent common stock.


LEGAL OPINION FOR LIMITED PARTNERS

     Each of the partnership agreements, except the partnership agreement for
Parker & Parsley Producing Properties 88-A, L.P., requires that special legal
counsel render an opinion on behalf of the limited partners of each partnership
to Pioneer USA that neither the grant nor the exercise of the right to approve
the merger of the partnership by its limited partners will adversely affect the
federal income tax classification of the partnership or any of its limited
partners. In addition, the partnership agreement for each of the following
partnerships requires an opinion that neither the grant nor exercise of such
right will result in the loss of any limited partner's limited liability:


                                                          
     Parker & Parsley 81-1, Ltd.                             Parker & Parsley Selected 85 Private Investment, Ltd.
     Parker & Parsley 81-II, Ltd.                            Parker & Parsley 86-A, Ltd.
     Parker & Parsley 82-I, Ltd.                             Parker & Parsley 86-B, Ltd.
     Parker & Parsley 82-II, Ltd.                            Parker & Parsley 86-C, Ltd.
     Parker & Parsley 82-III, Ltd.                           Parker & Parsley Private Investment 86, Ltd.
     Parker & Parsley 83-A, Ltd.                             Parker & Parsley 87-A Conv., Ltd.
     Parker & Parsley 83-B, Ltd.                             Parker & Parsley 87-A, Ltd.
     Parker & Parsley 84-A, Ltd.                             Parker & Parsley 87-B, Ltd.
     Parker & Parsley 85-A, Ltd.                             Parker & Parsley Producing Properties 87-A, Ltd.
     Parker & Parsley 85-B, Ltd.                             Parker & Parsley Producing Properties 87-B, Ltd.
     Parker & Parsley Private Investment 85-A, Ltd.


     For each of the partnerships, other than those listed below, the counsel
designated to render the opinion described above must be counsel other than
counsel to Pioneer USA or any partnership:


                                                          
     Parker & Parsley 88-A Conv., L.P.                       Parker & Parsley 90-A Conv., L.P.
     Parker & Parsley 88-A, L.P.                             Parker & Parsley 90-A, L.P.
     Parker & Parsley 88-B Conv., L.P.                       Parker & Parsley 90-B Conv., L.P.
     Parker & Parsley 88-B, L.P.                             Parker & Parsley 90-B, L.P.
     Parker & Parsley 88-C Conv., L.P.                       Parker & Parsley 90-C Conv., L.P.
     Parker & Parsley 88-C, L.P.                             Parker & Parsley 90-C, L.P.
     Parker & Parsley Private Investment 88, L.P.            Parker & Parsley Private Investment 90, L.P.
     Parker & Parsley 89-A Conv., L.P.                       Parker & Parsley 90 Spraberry Private Dev., L.P.
     Parker & Parsley 89-A, L.P.                             Parker & Parsley 91-A, L.P.
     Parker & Parsley 89-B Conv., L.P.                       Parker & Parsley 91-B, L.P.
     Parker & Parsley 89-B, L.P.
     Parker & Parsley Private Investment 89, L.P.



     In all cases, the designated counsel and the legal opinion must be approved
by the limited partners of each partnership.


     In all cases, Pioneer USA has retained             of Dallas, Texas for the
purpose of rendering the legal opinions described above on behalf of the limited
partners of each partnership to Pioneer USA.            is not affiliated to
Pioneer Parent, Pioneer USA or any of the partnerships. The merger proposals for
each partnership include an approval of that counsel and the form of its
opinion. See "The Special Meetings -- Time and Place; Purpose" on page 58 of
this document. A copy of the opinion is attached as an exhibit to the merger
proposals for each partnership.



                                      -47-
   58



DISTRIBUTION OF PIONEER PARENT COMMON STOCK



     Upon completion of the merger of each participating partnership, the
partners of the partnership will have no continuing interest in, or rights as
partners of, the partnership. The transfer books of each participating
partnership will be closed on the closing date of the merger of the partnership.
All partnership interests in each participating partnership will cease to be
outstanding, will automatically be cancelled and retired, and will cease to
exist. The certificates previously representing partnership interests in each
participating partnership held by record partners will represent only the right
to receive Pioneer Parent common stock.



     We intend to mail certificates representing Pioneer Parent common stock to
the partners of record of each participating partnership promptly following the
effectiveness of the merger of the partnership in payment of the merger value
for the partnership. Partners of each participating partnership will not be
required to surrender partnership interest certificates to receive the Pioneer
Parent common stock.


FRACTIONAL SHARES


     Pioneer Parent will not issue fractional shares to any limited partner upon
completion of the merger of any partnership. For each fractional share that
would otherwise be issued, Pioneer Parent will round any fractional shares of
Pioneer Parent common stock up to the nearest whole share.


MATERIAL U.S. FEDERAL INCOME TAX CONSEQUENCES


     The following discussion describes the material federal income tax
consequences of a conversion of partnership interests into Pioneer Parent common
stock pursuant to the merger of each participating partnership. The federal tax
consequences of each merger will vary for each limited partner because of the
different circumstances of each participating partnership and the individual
federal income tax position of each limited partner.



     Except as otherwise indicated, statements of legal conclusion regarding tax
treatments, tax effects or tax consequences are the opinions of Vinson & Elkins
L.L.P, counsel for Pioneer Parent based upon current law. Future legislative,
judicial or administrative changes or interpretations could alter or modify the
following statements and conclusions, and any of these changes or
interpretations could be retroactive and could affect the tax consequences to
the limited partners of each partnership.


     The following discussion is not exhaustive of all possible tax
consequences. It does not address any state, local or foreign tax consequences,
nor does it discuss all of the aspects of federal income taxation that may be
relevant to specific partners in light of their particular circumstances. The
discussion below describes material federal income tax consequences applicable
to individuals who are citizens or residents of the United States, and therefore
has limited application to domestic corporations and persons subject to
specialized federal income tax treatment, such as foreign persons, tax-exempt
entities, regulated investment companies and insurance companies.


     A copy of the tax opinion of Vinson & Elkins has been filed as an exhibit
to the registration statement of which this document is a part. Vinson & Elkins'
tax opinion is based, in part, on various assumptions of fact and certificates.



     The following discussion does not address the particular facts and
circumstances of any particular limited partner. You are advised to consult your
own tax advisor to determine all of the relevant federal, state and local tax
consequences of each merger particular to you.


TAX CONSEQUENCES OF A CONVERSION OF PARTNERSHIP INTERESTS.


     o Generally. As more fully described below, if you own partnership
interests in a participating partnership, you will generally recognize an
aggregate amount of net gain or loss equal to the difference between (1) the
fair market value of Pioneer Parent common stock you receive in the merger of
that partnership and (2) your adjusted tax basis in your partnership interests
exclusive of any basis attributable to liabilities of the partnership
immediately prior to the merger. That net gain or loss may be comprised of
ordinary income or ordinary loss depending upon the extent of any recapture of
depletion or intangible drilling and development costs and any appreciation or
depreciation in the ordinary assets of the partnership. The recognition of
ordinary income will decrease the capital gain component or increase the capital
loss component of the net gain or loss otherwise recognizable as a consequence
of the merger.



     o Characterization of the Merger of Each Partnership. The merger of a
participating partnership into Pioneer USA should be treated for federal income
tax purposes as a sale by such partnership of its assets for Pioneer Parent
common stock followed by a distribution of the Pioneer Parent common stock
received in liquidation of the limited partnership interests. Under Section 613A
of the Internal Revenue Code, each of the partners of such partnership must:



                                      -48-
   59


          -    maintain the partner's share of the basis in the partnership's
               oil and gas properties at the partner level;

          -    adjust such basis for depletion deductions; and

          -    use such basis to calculate gain or loss at the partner level on
               any sale by the partnership of its oil and gas properties.

     Accordingly, each of the mergers should be generally treated for tax
computation purposes as:


          -    a taxable sale by you of your interest in a participating
               partnership's oil and gas properties for Pioneer Parent common
               stock and the assumption of liabilities; and



          -    a taxable sale of any remaining partnership assets by the
               participating partnership for Pioneer Parent common stock
               followed by a liquidation of the participating partnership.


     o Gain or Loss on Sale of Partnership Oil and Gas Properties. Upon the
deemed sale of a partnership's oil and gas properties in the merger of the
partnership, you will recognize gain or loss equal to the difference between:

          -    the portion of the partnership's "amount realized" on the sale of
               its oil and gas properties allocated to you; and

          -    your adjusted tax basis in the partnership oil and gas properties
               sold, which must be reduced to reflect depletion claimed during
               the current year in respect of production prior to the date of
               the merger.


     The amount realized will include the fair market value of Pioneer Parent
common stock received and the amount of any liability assumed by Pioneer USA in
connection with the merger of the partnership which is attributable to the
partnership's oil and gas properties. If gain is recognized on such sale, the
portion of the gain that is treated as recapture of intangible drilling and
development costs or depletion will be treated as ordinary income. See
"Recapture of Intangible Drilling and Development Costs" and "Recapture of
Depletion" below. The remainder of such gain generally will constitute "Section
1231 gain." If loss is recognized on such sale, such loss generally will
constitute "Section 1231 loss." See "Section 1231 Gains and Losses" below. You
must take into account your share of the portion of the gain that constitutes
recapture income, if any, as ordinary income and must aggregate your share of
the Section 1231 gains and losses along with the Section 1231 gains and losses
you realize from other sources.


     o Other Gain or Loss. You will also recognize your allocable share of the
partnership's gain or loss, if any, on the deemed sale of its assets other than
oil and gas properties. Such gain or loss will be equal to the difference
between the amount realized by the partnership on the sale of such assets and
the partnership's adjusted tax basis in such assets. Such gain or loss will be
capital or ordinary depending on the nature of the assets sold.


     Finally, in the event that the fair market value of Pioneer Parent common
stock you receive in the merger of the partnership is more or less than the
adjusted tax basis in your partnership interests, as adjusted to reflect gains
and losses described in the two preceding paragraphs as well as the effects of
the partnership's current year activities, then upon the deemed liquidation of a
partnership, you will recognize capital gain or loss equal to the difference
between such amounts. See "Tax Consequences of Partnership Operations" below.



     You will be provided with information necessary to make the calculations
under Section 613A of the Internal Revenue Code described above for purposes of
filing your own federal income tax return. In order to simplify your federal
income tax reporting, this information will include a calculation of the amount
and character of your gain on the deemed sale of the partnership's oil and gas
properties based upon our estimates. You should verify the accuracy of these
calculations based upon your own records.


     o Section 1231 Gains and Losses. Generally, if the total amount of the
Section 1231 gains exceeds the total amount of Section 1231 losses, all such
gains and losses will be treated as capital gains and losses, and if the total
amount of the Section 1231 losses exceeds the total amount of the gains, all
such gains and losses will be treated as ordinary income and losses. However,
your net Section 1231 gains will be treated as ordinary income to the extent of
your net Section 1231 losses during the immediately preceding five years,
reduced by any amount of net Section 1231 losses that have been previously
"recaptured" by you pursuant to this rule.

     o Recapture of Intangible Drilling and Development Costs. Generally, all or
a portion of the amounts previously deducted for intangible drilling and
development costs for a property must be recaptured upon the disposition of such
property by treating the gain, if any, realized on such disposition as ordinary
income to the extent of such amounts. For a property placed in service prior to
1987, the potential recapture amount is equal to the excess of the aggregate
amounts previously deducted for intangible drilling and development costs for
such property over the amount by which the deduction for depletion for such
property would have been increased had the intangible drilling and development
costs been capitalized and recovered through depletion rather than deducted in
the year incurred. It


                                      -49-
   60


should be noted that, if percentage depletion, rather than cost depletion, has
been claimed for such property, the hypothetical capitalization of intangible
drilling and development costs may result in little or no increase in depletion
deductions and, as a consequence, most or all of the intangible drilling and
development costs for such property may be subject to recapture. For property
placed in service during 1987 or thereafter, the full amount of intangible
drilling and development costs previously deducted, unreduced by depletion, is
subject to recapture to the extent of any gain.

     o Recapture of Depletion. Upon the disposition of a property that was
placed in service during 1987 or thereafter, all amounts previously deducted for
depletion, whether cost depletion or percentage depletion, to the extent such
amounts reduced the basis in the property, must be recaptured by treating the
gain, if any, recognized on such disposition as ordinary income to the extent of
such amounts. No such recapture rule is applicable to a property placed in
service before 1987.


     o Tax Rates. The capital gains rate for individuals and other non-corporate
taxpayers is 20% if the capital asset has been held for more than one year at
the time of consummation of the merger of each partnership. Corporate taxpayers
are taxed at a maximum marginal rate of 35% for both capital gains and ordinary
income. The maximum marginal federal income tax rate for ordinary income of
individuals and other non-corporate taxpayers is currently 39.1%. Capital losses
are deductible only to the extent of capital gains, except that, subject to the
passive activity loss limitation discussed below, non-corporate taxpayers may
deduct up to $3,000 of capital losses in excess of the amount of their capital
gains against ordinary income. Excess capital losses generally can be carried
forward to succeeding years. A corporation is permitted to carry back excess
capital losses to the three preceding years, provided the carryback does not
increase or produce a net operating loss for any of those years. A corporation's
carryforward period is five years and a non-corporate taxpayer can carry such
losses forward indefinitely.


     o Passive Activity Loss Limitation. Under Section 469 of the Internal
Revenue Code, any losses from any participating partnership that have been
suspended under the passive loss rules will become fully deductible as a result
of the merger of any such partnership.


FIRPTA Withholding. Gain recognized by a foreign limited partner on the sale by
a participating partnership which is effectively connected with the conduct of a
U.S. trade or business of its assets pursuant to the merger of the partnership
will be subject to federal income tax. Gain recognized on the sale of U.S. real
property, including a participating partnership's oil and gas properties, is
treated as effectively connected with the conduct of a U.S. trade or business
for this purpose. Under Internal Revenue Code Section 1446, a participating
partnership in which an interest is held by a foreign person generally is
required to deduct and withhold a tax equal to the highest marginal federal
income tax rate applicable to the partner multiplied by such partner's allocable
share of effectively connected income. In order to comply with this requirement,
each participating partnership will withhold the prescribed percentage of the
effectively connected income allocated to you unless you properly complete and
sign a certification of non-foreign status certifying your taxpayer
identification number and address, and that you are not a foreign person.
Amounts withheld will be creditable against a limited partner's federal income
tax liability and, if in excess thereof, a refund may be obtained from the
Internal Revenue Service by filing a U.S. income tax return.


Tax Consequences of Partnership Operations. The federal income tax consequences
of the merger of each partnership, described above, are in addition to the tax
consequences of a participating partnership for the taxable year ending on the
closing date of the merger of the partnership. You must include your allocable
share of a participating partnership's items of income, gain, loss, deduction
and credit for that taxable year, including your allocable share through the
closing date of the merger of the partnership, on your federal income tax return
for that taxable year. That information will be provided to you on a Schedule
K-1 as required by tax law. The results of partnership operations for such
period will impact your tax basis in a participating partnership, and your
computation of gain or loss resulting from the merger of the partnership.

ACCOUNTING TREATMENT

     The merger of each participating partnership will be accounted for as a
purchase under generally accepted accounting principles. Under those rules,
Pioneer USA will record the assets and liabilities of each participating
partnership on its books at its estimated fair market value.


EFFECT OF DEBT OWED BY A LIMITED PARTNER TO PIONEER USA ON AMOUNT OF PIONEER
PARENT COMMON STOCK TO BE RECEIVED BY THE LIMITED PARTNER



     If a limited partner is indebted to Pioneer USA for any portion of the
limited partner's original investment in the partnership, Pioneer USA plans to
apply the Pioneer Parent common stock that would otherwise be distributed to the
limited partner upon completion of the merger of the partnership against that
limited partner's indebtedness. If a limited partner's indebtedness to Pioneer
USA is less than the merger value allocated to limited partnership interests
held by the limited partner, the limited partner will receive Pioneer Parent
common stock equal to the amount by which such merger value exceeds such
indebtedness. If a limited partner's indebtedness to Pioneer USA is greater



                                      -50-
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than the merger value allocated to the limited partnership interests held by the
limited partner, Pioneer USA may collect the deficiency from the limited
partner.

EFFECT OF MERGER OF EACH PARTNERSHIP ON LIMITED PARTNERS WHO DO NOT VOTE IN
FAVOR OF THE MERGER; NO APPRAISAL OR DISSENTERS' RIGHTS


     You will be bound by the merger of each partnership in which you own an
interest if the limited partners in the partnership vote a majority, or 66-2/3%
for Parker & Parsley 91-A, L.P. and Parker & Parsley 91-B, L.P., of their
partnership interests in favor of the merger, even if you vote against the
merger or do not vote. If the merger of the partnership occurs, you will be
entitled to receive only Pioneer Parent common stock based on the merger value
of your partnership interests in the partnership. Under the laws of the State of
Delaware and the State of Texas, which are the states of formation of the
partnerships, you are not entitled to appraisal or dissenters' rights with
respect to the merger of any partnership.


FUTURE OF NONPARTICIPATING PARTNERSHIPS


     If the limited partners of a partnership do not approve the merger of that
partnership, the partnership will remain in existence. Each nonparticipating
partnership will continue to operate as a separate legal entity with its own
assets and liabilities. There will be no immediate change in its business
objectives, and Pioneer USA plans to continue to manage and operate each
nonparticipating partnership in accordance with the terms of its current
partnership agreement. A limited partner in a nonparticipating partnership will
retain the rights, privileges and obligations that the limited partner currently
has pursuant to the partnership agreement of the nonparticipating partnership.
At about the same time that Pioneer USA mails certificates for Pioneer Parent
common stock to the partners of each participating partnership in payment of the
merger value for the partnership, Pioneer USA will mail any cash distributions
that were delayed for administrative purposes prior to the completion of the
merger of each participating partnership to the partners of each
nonparticipating partnership.



     Pioneer USA's board of directors will determine each nonparticipating
partnership's business plan. In addition, the board of directors of each of
Pioneer Parent and Pioneer USA will decide what, if any, actions they will take
with respect to each nonparticipating partnership. Potential activities may
include a tender offer for partnership interests of limited partners or a
proposal to acquire the assets of, or merge with, one or more of the
nonparticipating partnerships. Such proposals may be on terms similar to or
different from those of the merger of each partnership described in this
document.



     Pioneer USA plans to continue to manage each nonparticipating partnership
until such partnership is dissolved or Pioneer USA is replaced as the general
partner of such partnership. The replacement of Pioneer USA as general partner
would require compliance with the partnership agreement of such nonparticipating
partnership, including the requisite vote of the limited partners thereof. A
nonparticipating partnership may be dissolved in the future in accordance with
its partnership agreement if Pioneer USA or any substituted general partner
withdraws from the nonparticipating partnership, or in some cases, otherwise
elects to dissolve that partnership. Pioneer USA might withdraw from, or
otherwise elect to dissolve, a nonparticipating partnership if Pioneer USA
determines that the nonparticipating partnership's continued operation is
uneconomical or its dissolution and liquidation are in the best interests of the
partners of that partnership. Upon dissolution, the nonparticipating
partnership's assets may be sold for cash or securities, which may be more or
less than the merger value assigned to that partnership, or distributed in kind
to the partners of the nonparticipating partnership. Any such sale may be to
Pioneer Parent or an affiliate of Pioneer Parent and may involve cash or
securities of Pioneer Parent.


NONMANAGING GENERAL PARTNERS OF SOME PARTNERSHIPS


     Eight of the partnerships described in this document have two general
partners. In those eight partnerships, Pioneer USA is the managing general
partner. The second general partner in those partnerships is a parallel
partnership whose limited partners are former affiliates of Pioneer Parent's
predecessors. The names of the eight partnerships and the names of the
nonmanaging general partner in each of those partnerships are:





             PARTNERSHIP                    NONMANAGING GENERAL PARTNER
             -----------                    ---------------------------
                                         
     Parker & Parsley 81-I, Ltd.             P&P Employees 81-I, Ltd.
     Parker & Parsley 81-II, Ltd.            P&P Employees 81-II, Ltd.
     Parker & Parsley 82-I, Ltd.             P&P Employees 82-I, Ltd.
     Parker & Parsley 82-II, Ltd.            P&P Employees 82-II, Ltd.
     Parker & Parsley 82-III, Ltd.           P&P Employees 82-III, Ltd.
     Parker & Parsley 83-A, Ltd.             P&P Employees 83-A, Ltd.
     Parker & Parsley 83-B, Ltd.             P&P Employees 83-B, Ltd.
     Parker & Parsley 84-A, Ltd.             P&P Employees 84-A, Ltd.




                                      -51-
   62


     Pioneer USA is the sole general partner of each of the nonmanaging general
partners. In that capacity, Pioneer USA has authority:

     o    to cause the nonmanaging general partner to perform its obligations
          relating to the partnership described above; and

     o    to exercise on behalf of the nonmanaging general partner all of the
          rights and elections granted to the nonmanaging general partner by the
          partnership described above.


     None of the nonmanaging general partners has the right to vote on the
merger of any partnership. However, Pioneer USA, as the general partner of each
nonmanaging general partner, has approved the merger of each partnership and the
distribution of this document to the limited partners of each partnership and to
the unaffiliated limited partners of each nonmanaging general partner, if any,
of each partnership. The merger value attributable to the unaffiliated limited
partners of the nonmanaging general partners is $199,780, consisting of
approximately 11,099 shares of Pioneer Parent common stock in the aggregate.
Pioneer USA will not receive any Pioneer Parent common stock in any merger for
its partnership interests in any nonmanaging general partner.


THIRD PARTY OFFERS


     Pioneer USA will consider offers from third parties to purchase any
partnership or its assets. Those who wish to make an offer for any partnership
or its assets must demonstrate to Pioneer USA's reasonable satisfaction their
financial ability and willingness to complete such a transaction. Before
reviewing non-public information about a partnership, a third party will need to
enter into a customary confidentiality agreement. Offers should be at prices and
on terms that are fair to the partners of the partnership for which the offer is
being made and more favorable to the unaffiliated limited partners than the
prices and terms proposed for the merger of that partnership in this document.
Pioneer Parent reserves the right to match or top any such offer. In addition,
any such offer would be subject to Pioneer USA's right to continue operation of
the properties. Since first announcing our willingness to consider third party
offers in September 1999, Pioneer USA has not received any third party offer for
any partnership or its assets. Persons desiring to make an offer for any
partnership should contact Timothy L. Dove or Mark L. Withrow, Board of
Directors, Pioneer Natural Resources USA, Inc., 1400 Williams Square West, 5205
North O'Connor Boulevard, Irving, Texas 75039 by August 1, 2001.


MERGER AMENDMENT


     In order to complete the merger of each partnership, the partnership
agreement for the partnership requires an amendment to add a provision
permitting the merger of the partnership with and into Pioneer USA. See the
merger proposals, which include the merger amendment, set forth in Appendix E to
this document. At the special meeting for each partnership, the limited partners
of the partnership will vote upon the merger amendment, which, if approved, will
be effective immediately prior to the effectiveness of the merger of the
partnership.


TERMINATION OF REGISTRATION AND REPORTING REQUIREMENTS

     As a result of the merger of each participating partnership, the
partnership interests in the partnership, as well as the partnership itself,
will cease to exist. Twenty-five of the partnerships described in this document
have registered their partnership interests under, or are otherwise subject to
the informational requirements of, the Securities Exchange Act of 1934. See
"Where You Can Find More Information" for a list of those partnerships. Upon the
completion of the merger of each reporting partnership, Pioneer USA intends to
terminate:

     o    registration of the partnership interests of the partnership under the
          Securities Exchange Act of 1934; and

     o    the partnership's obligations to file reports and other information
          under the Securities Exchange Act of 1934.

     Pioneer USA plans to cause each nonparticipating partnership that is also a
reporting partnership to continue to file reports and other information under
the Securities Exchange Act of 1934. However, Pioneer USA's board of directors
could determine in the future to cause each such partnership to terminate its
reporting obligations as permitted by federal securities laws.

     The advantages of remaining registered, or remaining obligated to file
reports, under the Securities Exchange Act of 1934 include the informational and
reporting requirements under that act, including requirements related to tender
offers, proxy solicitation and consents and insiders' transactions in
partnership interests. Those reporting requirements may provide limited partners
with more detailed information on a more frequent basis than might otherwise be
required under the partnership agreement for the partnership. In addition, a
partnership's filings under the Securities Exchange Act of 1934 are available to
the public over the Internet at the SEC's web site at http://www.sec.gov and are
also available at the SEC's public reference rooms in Washington, D.C., New
York, New York and Chicago, Illinois.


                                      -52-
   63


     The disadvantages of remaining registered, or remaining obligated to file
reports, include the partnership's cost to prepare and distribute the various
reports and other information required under the Securities Exchange Act of
1934. Deregistering the partnership interests of a nonparticipating partnership
or otherwise terminating its filing and reporting obligations could reduce that
partnership's general and administrative expenses because the reporting
obligations of the partnership under its partnership agreement require annual
and semi-annual reports, but not quarterly reports.

ELIMINATION OF A FAIRNESS OPINION REQUIREMENT THAT WOULD OTHERWISE BENEFIT
PIONEER USA

     Pioneer USA, as the sole general partner of each of Parker & Parsley 91-A,
L.P. and Parker & Parsley 91-B, L.P., is entitled to receive an opinion as to
the fairness of the proposed merger transaction to Pioneer USA in its capacity
as sole general partner of each of those partnerships. However, since Pioneer
Parent and Pioneer USA are the parties making the offer for the proposed merger
transaction, Pioneer USA will not seek such fairness opinion. In addition,
Pioneer USA, as the sole general partner of each of those two partnerships, is
entitled to amend, and Pioneer USA will amend, the partnership agreement for the
partnership to eliminate the requirement for such fairness opinion for Pioneer
USA in connection with the proposed merger of the partnership.


PAYMENT OF EXPENSES AND FEES



     Pioneer Parent and Pioneer USA estimate that the aggregate expenses and
fees of the mergers of all of the partnerships will be as follows:




                                                                   
Filing fee with SEC.................................................. $   20,500
Legal fees...........................................................    350,000
Accounting fees......................................................    100,000
Financial advisor fees...............................................    350,000
Independent petroleum consultant fees................................     50,000
Printing and mailing fees............................................    850,000
Information agent fees and solicitation and tabulation expenses......    225,000
Miscellaneous........................................................     54,500
                                                                      ----------
    Total expenses................................................... $2,000,000
                                                                      ==========




     Each participating partnership will pay its pro rata share, based on its
reserve value, of the aggregate estimated expenses and fees of the mergers of
all of the partnerships. Each nonparticipating partnership will pay a portion of
the aggregate estimated expenses and fees of the mergers otherwise allocable to
such nonparticipating partnership based on a fraction, the numerator of which is
the percentage of the partnership's limited partnership interests that are voted
in favor of the merger proposals and the denominator of which is the percentage
of the partnership's limited partnership interests for which votes are cast.
Pioneer Parent has agreed to pay (1) the remainder of the estimated expenses and
fees otherwise allocable to such nonparticipating partnership, (2) any expenses
and fees actually incurred in excess of $2.0 million, and (3) if Pioneer Parent
terminates or abandons the merger as to any partnership, any expenses or fees
allocated to that partnership. Pioneer Parent and Pioneer USA have reduced the
net working capital component of each partnership's merger value by that
partnership's pro rata share of the estimated expenses and fees.



                                      -53-
   64


                              THE MERGER AGREEMENT


     The following describes the material terms of the merger agreement. Pioneer
Parent and Pioneer USA expect to sign the merger agreement as soon as the
Securities and Exchange Commission declares effective under the Securities Act
of 1933 the registration statement that includes this document. The full text of
the form of the merger agreement is attached as Appendix F to this document and
is incorporated by reference in this document. We encourage you to read the
entire merger agreement.


STRUCTURE; EFFECTIVE TIME

     The merger agreement provides for the merger of each participating
partnership with and into Pioneer USA, with Pioneer USA surviving each merger.
Each merger will become effective at the time of the filing of the certificate
of merger for each participating partnership with the Secretary of State of the
State of Delaware and, for each participating partnership formed in Texas, with
the Secretary of State of the State of Texas. Each certificate of merger is
expected to be filed as soon as practicable after the last condition precedent
to the related merger set forth in the merger agreement has been satisfied or
waived. We estimate that the closing of the merger of each partnership will be
in the third quarter of 2001.


EFFECT OF THE MERGER OF EACH PARTNERSHIP


     As a result of the merger of each participating partnership, the partners
in the partnership will have no continuing interest in that partnership.
Following the merger of each participating partnership, there will be no trading
market for the partnership interests in, and no further distributions paid to
the former partners of, the partnership. In addition, following the consummation
of the merger of each participating partnership that is also a reporting
partnership, the registration of any partnership interests in the partnership
under the Securities Exchange Act of 1934 will be terminated.


CONDUCT OF BUSINESS PRIOR TO THE MERGER OF EACH PARTNERSHIP


     From the date of the merger agreement until the effective time of the
merger of each partnership, each partnership is required:

     o    to conduct its business only in the ordinary course consistent with
          past practice; and

     o    to use its reasonable best efforts:

          -    to preserve intact its business organization;

          -    to keep available the services of its officers, employees and
               consultants; and

          -    to preserve its relationships with customers, suppliers and other
               persons with which it has significant business dealings.


     Pioneer USA has suspended cash distributions to the partners of each
partnership until after the effective time of the merger of the partnership.
Partners of each nonparticipating partnership will receive cash distributions
that are delayed for administrative purposes at about the same time Pioneer USA
mails certificates for Pioneer Parent common stock to the partners of each
participating partnership in payment of merger value for each partnership.


OTHER AGREEMENTS

     Special Meetings; Proxies. Pioneer USA has agreed to cause the special
meeting of the limited partners of each partnership to be duly called and held
as soon as reasonably practicable for the purpose of voting on the approval and
adoption of the merger proposals for the partnership. Pioneer USA has also
agreed to use its reasonable best efforts to solicit from the limited partners
of each partnership proxies in favor of the merger proposals and to take all
other action necessary or advisable to secure any vote or consent of the limited
partners of the partnership required by the partnership agreement of the
partnership or the merger agreement or by law in connection with the merger of
the partnership.

     Reasonable Commercial Efforts. Each party has agreed to use all reasonable
commercial efforts:

     o    to obtain in a timely manner all necessary waivers, consents and
          approvals and to effect all necessary registrations and filings; and

     o    to take, or cause to be taken, all actions and to do, or cause to be
          done, all things necessary, proper or advisable under applicable laws
          and regulations to consummate as promptly as practicable the
          transactions contemplated by the merger agreement.


                                      -54-
   65


REPRESENTATIONS AND WARRANTIES OF PIONEER PARENT, PIONEER USA AND EACH
PARTNERSHIP


     The merger agreement contains substantially reciprocal representations and
warranties of Pioneer Parent, Pioneer USA and each of the partnerships,
including the following matters:


     o    due organization or formation, standing, corporate or partnership
          power and qualification;

     o    absence of any conflict, breach, notice requirement or default under
          organizational documents and material agreements as a result of each
          contemplated merger;

     o    authority to enter into and the validity and enforceability of the
          merger agreement;

     o    absence of any material adverse change since March 31, 2001; and

     o    accuracy of information.

     In addition, the merger agreement contains representations and warranties
by:

     o    each of the partnerships as to capitalization;


     o    each of Pioneer Parent and each reporting partnership, as to the
          absence in its reports filed with the SEC of any untrue statement of a
          material fact or any omission to state a material fact necessary to
          make the statements in such reports not misleading;



     o    each of Pioneer Parent and each partnership, that its financial
          statements have been prepared in accordance with generally accepted
          accounting principles applied on a consistent basis and fairly present
          its financial condition and results of operations; and


     o    Pioneer USA as to its capacity as the managing or sole general partner
          of each partnership and as the sole general partner of each
          nonmanaging general partner.

CONDITIONS TO THE MERGER OF EACH PARTNERSHIP


     Conditions to the Obligations of Each Party. The obligations of Pioneer
Parent, Pioneer USA and each partnership to complete the merger of the
partnership are dependent on the satisfaction of the following conditions:


     o    the merger agreement shall have been approved by the requisite vote of
          the limited partners of the partnership entitled to vote at the
          partnership's special meeting;

     o    Pioneer USA shall have received the fairness opinion from Stanger
          that, as of the date of that opinion, that the merger value for each
          partnership and the allocation of the merger value of the partnership
          (1) to the limited partners of the partnership as a group, (2) to the
          general partners of the partnership as a group, (3) to Pioneer USA as
          the managing or sole general partner of the partnership, (4) to the
          unaffiliated limited partners of the partnership as a group and (5) to
          the unaffiliated limited partners of the nonmanaging general partner,
          if any, of the partnership as a group, is fair to the unaffiliated
          limited partners of the partnership and the unaffiliated limited
          partners of the nonmanaging general partner, if any, of the
          partnership, from a financial point of view;

     o    Pioneer USA shall have received the opinion of counsel to the limited
          partners of each partnership that (1) neither the grant nor the
          exercise of the right to approve the merger of the partnership by its
          limited partners will adversely affect the federal income tax
          classification of the partnership or any of its limited partners and
          (2) neither the grant nor exercise of such right will result in the
          loss of any limited partner's limited liability;

     o    the absence of any law, regulation, judgment, injunction, order or
          decree that would prohibit the consummation of any merger;

     o    the absence of any pending suit, action or proceeding challenging the
          legality or any aspect of the merger of any partnership or the
          transactions related to the merger;


     o    the authorization for listing on the New York Stock Exchange and the
          Toronto Stock Exchange upon official issuance of notice shall have
          been received for the shares of Pioneer Parent common stock to be
          issued upon the merger of each partnership;



                                      -55-
   66


     o    all material filings and registrations with, and notifications to,
          third parties shall have been made and all material approvals and
          consents of third parties shall have been received; and

     o    the absence of any opinion of counsel that the exercise by the limited
          partners of each partnership of the right to approve the merger of the
          partnership is not permitted by state law.


     Conditions to the Obligations of Pioneer Parent. The obligations of Pioneer
Parent to complete the merger of each partnership are further subject to the
satisfaction of the following conditions:


     o    each of Pioneer USA and each partnership having performed in all
          material respects its agreements contained in the merger agreement;
          and

     o    the representations and warranties of Pioneer USA and each partnership
          being true and correct in all material respects at the closing date of
          the merger of the partnership as if made at that time unless they
          relate to another specified time.

     Conditions to the Obligations of Pioneer USA and Each Partnership. The
obligations of Pioneer USA and each partnership to complete the merger of the
partnership are further subject to the satisfaction of the following conditions:


     o    Pioneer Parent having performed in all material respects its
          agreements contained in the merger agreement; and



     o    the representations and warranties of Pioneer Parent being true and
          correct in all material respects at the closing date of the merger of
          the partnership as if made at that time unless they relate to another
          specified time.


TERMINATION OF THE MERGER AGREEMENT AND THE MERGER OF ANY PARTNERSHIP

     The merger agreement may be terminated and the merger of any partnership
abandoned at any time prior to the effective time, whether before or after
approval by the limited partners:

     o    by the mutual written consent of the parties;

     o    by any party, if:

          -    any applicable law, rule or regulation makes consummation of any
               merger illegal or otherwise prohibited or any final and
               non-appealable judgment, injunction, order or decree enjoining
               any party from consummating any merger is entered;

          -    the requisite limited partner approval for a partnership is not
               obtained by a vote at the special meeting for the partnership or
               at any adjournment or postponement of the special meeting; or


          -    any suit, action or proceeding is filed against Pioneer Parent,
               Pioneer USA, any partnership or any officer, director or
               affiliate of Pioneer Parent or Pioneer USA challenging the
               legality or any aspect of the merger of any partnership or the
               transactions related to the merger;



     o    by Pioneer Parent, if Pioneer USA or any partnership is in material
          breach of the merger agreement;



     o    by Pioneer USA or any partnership as to that partnership's merger, if
          Pioneer Parent is in material breach of the merger agreement;


     o    by Pioneer USA, if Pioneer USA's board of directors determines that
          termination of the merger agreement is required in order for the board
          to comply with its fiduciary duties; or


     o    by Pioneer Parent, if there shall have occurred any event,
          circumstance, condition, development or occurrence causing, resulting
          in or having, or reasonably expected to cause, result in or have, a
          material adverse effect (1) on any partnership's business, operations,
          properties, taken as a whole, condition, financial or otherwise,
          results of operations, assets, taken as a whole, liabilities, cash
          flows or prospects, (2) on market prices for oil and gas prevailing
          generally in the oil and gas industry since the date of determination
          of the oil and gas commodity prices used in the determination of the
          merger value for each partnership, (3) on the price of Pioneer Parent
          common stock or (4) on the oil and gas industry generally.



     If the merger agreement is validly terminated or the merger of any
partnership is abandoned, none of Pioneer Parent, Pioneer USA nor any such
partnership shall have any liabilities or obligations to the other parties based
on the merger agreement or such merger except:



                                      -56-
   67



     o    Pioneer Parent will pay all expenses and fees of each partnership in
          connection with the merger of that partnership incurred before the
          termination of the merger agreement or abandonment of the merger of
          the partnership; and


     o    a party will be liable if that party is in breach of the merger
          agreement.

AMENDMENTS; WAIVERS


     Any provision of the merger agreement may be amended prior to the effective
time if the amendment is in writing and signed by Pioneer Parent and Pioneer
USA; provided, that after the approval of the merger proposals by the limited
partners of each partnership, no amendment shall, without the further approval
of the limited partners of each partnership:


     o    adversely change the type or amount of, or the method of determining,
          the consideration to be received in exchange for any partnership
          interests in the partnership; or

     o    materially and adversely affect the rights of the limited partners of
          the partnership, other than a termination of the merger agreement or
          abandonment of the merger of the partnership.

     Prior to the effective time, the parties may:

     o    extend the time for the performance of any of the obligations of the
          parties;

     o    waive any inaccuracies in the representations and warranties in the
          merger agreement or in a document delivered pursuant to the merger
          agreement; and

     o    waive compliance with any agreement or condition in the merger
          agreement.

Any such extension or waiver will be valid only if it is in writing and signed
by the party against whom the extension or waiver is to be effective.


                                      -57-
   68

                              THE SPECIAL MEETINGS

TIME AND PLACE; PURPOSE

     The special meeting of the limited partners of each partnership will be
held on         , 2001, at 10:00 a.m., at the Dallas Marriott Las Colinas Hotel,
Irving, Texas 75039. The purpose of each special meeting, and any adjournment or
postponement of the special meeting for each partnership, is for the limited
partners of each partnership to consider and vote on the following matters:


     o A proposal to approve an Agreement and Plan of Merger dated as of       ,
2001, among Pioneer Parent, Pioneer USA and each of the partnerships. Each
participating partnership will merge with and into Pioneer USA, with Pioneer USA
surviving the merger. Each partnership interest of a participating partnership
will be converted into Pioneer Parent common stock. The number of shares of
common stock Pioneer Parent will offer for all partnership interests of a
participating partnership will be based on (1) the participating partnership's
merger value and (2) the average closing price of the Pioneer Parent common
stock, as reported by the New York Stock Exchange, for the ten trading days
ending three business days before the initial date of the special meeting for
the partnership. The merger value for a participating partnership is equal to
the sum of the present value of estimated future net revenues from the
partnership's estimated oil and gas reserves and its net working capital, in
each case as of March 31, 2001, less its pro rata share, based on its reserve
value, of the estimated expenses and fees of the mergers of all of the
partnerships and less the cash distribution to be mailed on or about July 12,
2001, by the partnership to its partners. For purposes of illustration in this
document, we have calculated the number of shares to be issued based on an
assumed average closing price of $18.00 per share of Pioneer Parent common
stock. Prior to the date of the special meeting for each partnership, we will
update the number of shares to be issued using the actual average closing price
of Pioneer Parent common stock for the ten trading days ending three business
days before the initial date of the special meeting. The Pioneer Parent common
stock will be allocated among the partners based on the liquidation provisions
of each partnership agreement. Pioneer Parent will not issue fractional shares
to any limited partner upon completion of the merger of any partnership.
Instead, Pioneer Parent will round any fractional shares of Pioneer Parent
common stock up to the nearest whole share. Pioneer USA will not receive any
Pioneer Parent common stock for its partnership interests in the participating
partnerships.


     o A proposal to amend the partnership agreement of each partnership to
permit the partnership's merger with Pioneer USA. If the amendment is not
approved, that partnership cannot merge into Pioneer USA even if the partners of
that partnership approve the merger agreement.

     o A proposal (A) to approve the opinion issued to Pioneer USA by
on behalf of the limited partners of each partnership that neither the grant nor
the exercise of the right to approve the merger of the partnership by its
limited partners (1) will result in the loss of any limited partner's limited
liability or (2) will adversely affect the federal income tax classification of
the partnership or any of its limited partners and (B) to approve the selection
of              as special legal counsel for the limited partners of each
partnership to render such legal opinion.




     The Delaware Revised Uniform Limited Partnership Act and the Texas Revised
Limited Partnership Act require limited partner approval and adoption of the
merger agreement and the merger amendment. Generally, the partnership agreement
of each partnership requires that special legal counsel for the limited partners
render its legal opinion related to the limited partners' approval of the merger
of that partnership. See "The Merger of Each Partnership -- Legal Opinion for
Limited Partners" on page 46 of this document.


     PIONEER USA'S BOARD OF DIRECTORS UNANIMOUSLY DETERMINED THAT THE MERGER OF
EACH PARTNERSHIP IS ADVISABLE, FAIR TO THE UNAFFILIATED LIMITED PARTNERS OF THE
PARTNERSHIP, AND IN THEIR BEST INTERESTS. THE BOARD RECOMMENDS THAT THE
UNAFFILIATED LIMITED PARTNERS VOTE FOR THE MERGER PROPOSALS FOR EACH PARTNERSHIP
IN WHICH THEY OWN AN INTEREST. ALTHOUGH PIONEER USA'S BOARD OF DIRECTORS HAS
ATTEMPTED TO FULFILL ITS FIDUCIARY DUTIES TO THE LIMITED PARTNERS OF EACH
PARTNERSHIP, PIONEER USA'S BOARD OF DIRECTORS HAD CONFLICTING INTERESTS IN
EVALUATING EACH MERGER BECAUSE EACH MEMBER OF ITS BOARD OF DIRECTORS IS ALSO AN
OFFICER OF PIONEER PARENT.

RECORD DATE; VOTING RIGHTS AND PROXIES

     Only limited partners of record of each partnership at the close of
business on , 2001 are entitled to notice of and to vote at the special meeting
for the partnership in which they own partnership interests, or any adjournments
or postponements of such special meeting. Pioneer USA is entitled to vote
partnership interests it holds as a limited partner in all of the partnerships
except:

              Parker & Parsley 85-A, Ltd.
              Parker & Parsley 85-B, Ltd.
              Parker & Parsley Private Investment 85-A, Ltd.
              Parker & Parsley Selected 85 Private Investment, Ltd.
              Parker & Parsley Private Investment 86, Ltd.


                                      -58-
   69


              Parker & Parsley 91-A, L.P.
              Parker & Parsley 91-B, L.P.


Pioneer USA's affiliates are also entitled to vote partnership interests they
hold as limited partners in all but the seven partnerships listed above.
However, no affiliates of Pioneer USA own such interests. See "Ownership of
Partnership Interests" on page 64 of this document.



     Limited partners of record of each partnership are entitled to vote at the
partnership's special meeting based on the limited partners' respective
percentage of partnership interests in the partnership. Each limited partner
will receive a proxy card for all partnerships in which that limited partner
holds partnership interests. The proxy card will indicate the amount of Pioneer
Parent common stock offered with respect to such partnership interests in each
partnership. Although the number of shares of Pioneer Parent common stock
offered as shown on the proxy card may change, the value of Pioneer Parent
common stock offered as shown on the proxy card will not be adjusted. The
percentage of partnership interests that a limited partner holds in a
partnership is determined by comparing the amount of the limited partner's
initial investment, including any additional assessments, in the partnership to
the total investment of all partners, including any additional assessments, in
the partnership. The aggregate initial investment, including any additional
assessments, in each of the partnerships by the limited partners is set forth in
Table 1 of Appendix A.



     A limited partner of record may grant a proxy to vote for or against, or
may abstain from voting on, the merger proposals applicable to each of the
partnerships in which the limited partner holds partnership interests. To be
effective for purposes of granting a proxy to vote on the merger proposals
applicable to each partnership, a proxy card must be properly completed,
executed and delivered to Pioneer USA's information agent, in person or by mail,
telegraph, telex or facsimile before the special meeting for the partnership.
All partnership interests represented by properly executed proxies will, unless
these proxies have been previously revoked, be voted in accordance with the
instructions indicated in these proxies. If no instructions are indicated, the
partnership interests will be voted for approval and adoption of the merger
proposals. A properly executed proxy card for a partnership marked abstain is
counted as present for purposes of determining the presence or absence of a
quorum at the special meeting for the partnership, but will not be voted.
Accordingly, abstentions will have the same effect as a vote against the merger
proposals.



     Unrevoked proxies granted in the proxy cards for a partnership will be
voted at the special meeting for that partnership or at any adjournment or
postponement of the special meeting, if received by Pioneer USA's information
agent before the special meeting for the partnership. Proxies granted in the
proxy cards for a partnership will remain valid until the completion of the
special meeting for the partnership. Each partnership agreement requires that a
meeting be held within 60 days of the date of mailing of the notice of meeting.
None of the partnership agreements specifically addresses, and Pioneer USA has
not sought any opinions of counsel as to, whether proxies may be voted at a
meeting originally scheduled to be held within 60 days of the sending of the
notice and adjourned or postponed to a date more than 60 days after the date of
notice. Pioneer USA will not accept a vote of the limited partners of any
partnership in such circumstances unless it receives an opinion of counsel that
such a vote would be valid.


     The inspector of election appointed for the special meeting for each
partnership will tabulate the votes cast by proxy or in person at the special
meeting.


REVOCATION OF PROXIES


     You may revoke a proxy you have given at any time before that proxy is
voted at the special meeting for each partnership in which you own an interest
by:

     o    giving written notice of revocation to Pioneer USA;

     o    signing and returning a later dated proxy; or

     o    voting in person at the special meeting.

Your notice of revocation will not be effective until Pioneer USA receives it at
or before the special meeting for each partnership in which you own an interest.
Your presence at any such special meeting will not automatically revoke your
proxy in a proxy card. Revocation during any such special meeting will not
affect votes previously taken.

     You may deliver your written notice of revocation in person or by mail,
telegraph, telex, or facsimile. Any written notice of revocation must specify
your name and limited partner number as shown on your proxy card and the name of
the partnership to which your revocation relates.


                                      -59-
   70


SOLICITATION OF PROXIES


     We are soliciting your proxy pursuant to this document. The aggregate
estimated expenses and fees of the merger of each partnership that have been
allocated to each partnership include those incurred in connection with
solicitation of the enclosed proxy as described below.



     Pioneer USA has retained D.F. King & Co., Inc. to assist in the
solicitation of proxies from the limited partners of each partnership. The total
fees and expenses of D.F. King & Co., Inc. are estimated to aggregate $225,000
and have been allocated among the partnerships, on a pro rata basis, based on
each partnership's reserve value. In addition to solicitation by use of the
mail, proxies may be solicited by D.F. King & Co., Inc. and by directors,
officers and employees of Pioneer Parent and Pioneer USA in person or by
telephone, telegram, facsimile or e-mail. The directors, officers and employees
will not be additionally compensated, but may be reimbursed for out-of-pocket
expenses incurred in connection with the solicitation.



     Arrangements may also be made with other brokerage firms, banks,
custodians, nominees and fiduciaries for the forwarding of proxy solicitation
materials to owners of limited partnership interests held of record by those
persons. Each partnership will pay its pro rata share, based on its reserve
value, of those persons' reasonable expenses incurred in forwarding those
materials.



     Pioneer USA has also retained D.F. King & Co., Inc. to act as information
agent to perform consulting, administration and clerical work with respect to
the merger of each partnership. Pioneer USA has agreed to indemnify D.F. King &
Co., Inc. against certain liabilities, including liabilities under the federal
securities laws. D.F. King & Co., Inc. will also be responsible for the receipt
and tabulation of the proxy cards. The fees and expenses of D.F. King & Co.,
Inc. for its services as information agent and tabulator are included in the
aggregate amount set forth above.



     We intend to mail certificates representing shares of Pioneer Parent common
stock to the partners of record of each participating partnership promptly after
completing the merger of that partnership. Certificates representing partnership
interests will be automatically canceled, and you will not have to surrender
your certificates to receive the Pioneer Parent common stock.


QUORUM

     The presence in person or by properly executed proxy of a majority of
limited partnership interests entitled to vote in each partnership is necessary
to constitute a quorum at that partnership's special meeting.

     If a quorum is not present at any special meeting, the limited partners
entitled to vote who are present or represented by proxy at that special meeting
may adjourn or postpone that special meeting without notice until a quorum is
present. If a quorum is present at the adjourned or postponed meeting, any
business may be transacted that may have been transacted at the special meeting
had a quorum originally been present. If the adjournment or postponement is for
more than 30 days or if after the adjournment or postponement a new record date
is fixed for the adjourned or postponed meeting, a notice of the adjourned or
postponed meeting shall be given to each limited partner of record entitled to
vote at the adjourned or postponed meeting. The persons named as proxies intend
to vote in favor of any motion to adjourn or postpone the special meeting of any
partnership if, prior to the special meeting, they have not received sufficient
proxies to approve the merger of the partnership as described in this document.
This process will be repeated at any adjourned or postponed meeting until
sufficient proxies to vote in favor of the merger of the partnership have been
received or it appears that sufficient proxies will not be received.

REQUIRED VOTE; BROKER NON-VOTES


     Approval of the merger proposals for each partnership requires the
affirmative vote of the limited partners holding a majority of limited
partnership interests in that partnership, except that Parker & Parsley 91-A,
L.P. and Parker & Parsley 91-B, L.P. each require the favorable vote of the
holders, other than Pioneer USA, of 66-2/3% of its limited partnership interests
to approve those merger proposals. Pioneer USA is entitled to vote its
partnership interests on the merger proposals for each partnership except for
the partnerships set forth under "The Special Meetings -- Record Date; Voting
Rights and Proxies" on page 58. As a result, for each partnership in which
Pioneer USA is entitled to vote, approval of at least a majority, and for Parker
& Parsley 91-A, L.P. and Parker & Parsley 91-B, L.P., at least 66-2/3%, of the
unaffiliated limited partners is not required to approve the merger proposals.
However, for each partnership in which Pioneer Parent is not entitled to vote,
the approval of the unaffiliated limited partners is required to approve the
merger proposals.


     Brokers, if any, who hold partnership interests in street name for
customers have the authority to vote on "routine" proposals when they have not
received instructions from beneficial owners. However, these brokers are
precluded from exercising their voting discretion with respect to the approval
and adoption of non-routine matters such as the merger proposals and thus,
absent specific instructions from the beneficial owner of the partnership


                                      -60-
   71


interests, brokers are not empowered to vote the partnership interests with
respect to the merger proposals. These "broker non-votes" will have the effect
of a vote against the merger proposals.

PARTICIPATION BY ASSIGNEES


     Pioneer USA has the discretionary authority granted to it under each
partnership agreement to withhold its consent to the substitution of any
assignees as partners of the partnership. To facilitate the notification given
to limited partners of each partnership about the merger of the partnership,
Pioneer USA intends to exercise that authority and withhold its consent to the
substitution of any assignees as partners of the partnership from the date on
which this document is initially filed with the SEC until the earlier to occur
of the closing date of the merger of the partnership, or the termination or
abandonment of the transaction by Pioneer Parent and Pioneer USA.


SPECIAL REQUIREMENTS FOR SOME LIMITED PARTNERS

     Pioneer USA may require that any proxy card executed by an entity, such as
a trust, corporation, or partnership, be accompanied by evidence or an opinion
of counsel that such entity:

     o    has met all requirements of its governing instruments; and

     o    is authorized to execute and deliver the proxy card under the laws of
          the jurisdiction under which the entity was organized.

     Pioneer USA will require the named trustee and the beneficial owner of
trusts, including individual retirement accounts, to execute the proxy card. In
some cases, Pioneer USA may provide a limited partner with an envelope,
pre-addressed to his individual retirement account trustee, so that the limited
partner may forward his executed proxy card to the trustee for the trustee's
signature, if necessary, and subsequent delivery to Pioneer USA. Delivery of a
proxy card to the trustee, with or without the use of a pre-addressed envelope,
and delivery of a proxy card from the trustee to Pioneer USA are at the risk of
the limited partner.

VALIDITY OF PROXY CARDS

     A proxy card will not be valid unless it has been properly completed and
executed and timely delivered to Pioneer USA's information agent with all other
required documents. Pioneer USA will determine all questions as to the validity,
form, eligibility, time of receipt and acceptance of a proxy card and its
determination will be final and binding. Pioneer USA's interpretation of the
terms and conditions of the merger of each partnership, including the
instructions for the proxy card, will also be final and binding.

     A proxy card will not be valid until any irregularities have been cured or
waived. If Pioneer USA does not waive the irregularities, it will return the
defective proxy card to the limited partner as soon as practicable. Pioneer USA
is under no duty to give notification of defects in a proxy card and will incur
no liability if it fails to give such notification.

     Delivery of a proxy card is at the risk of the limited partner. A proxy
card will be effective for purposes of voting only when it is actually received
by Pioneer USA's information agent. To ensure receipt of the proxy card and all
other required documents, Pioneer USA suggests that limited partners use
overnight courier delivery or certified or registered mail, return receipt
requested.

LOCAL LAWS


     Proxy solicitations will not be made to, nor will proxy cards be accepted
from, limited partners of any partnership in any jurisdiction in which the
solicitations would not be in compliance with federal and state securities or
other laws. In any jurisdiction where securities laws require the proxy
solicitations to be made by a licensed broker or dealer, the proxy solicitations
are being made on behalf of Pioneer Parent and Pioneer USA by , which is
licensed under the laws of such jurisdiction.



                                      -61-
   72
           COMPARATIVE PER SHARE MARKET PRICE AND DIVIDEND INFORMATION


     The table below sets forth, for the calendar quarters indicated, the
reported high and low closing prices of Pioneer Parent common stock as reported
on the New York Stock Exchange Composite Transaction Tape, in each case based on
published financial sources. Pioneer Parent's board of directors did not declare
dividends to the holders of Pioneer Parent common stock during 1999, 2000 or the
three months ended March 31, 2001. The determination of the amount of future
cash dividends, if any, to be declared and paid is in the sole discretion of
Pioneer Parent's board of directors and will depend on the following factors:



     o    Pioneer Parent's financial condition;



     o    earnings and funds from operations;



     o    the level of Pioneer Parent's capital and exploration expenditures;



     o    dividend restrictions in Pioneer Parent's financing agreements;



     o    Pioneer Parent's future business prospects; and



     o    other matters that Pioneer Parent's board of directors deems relevant.


     None of the partnership interests of any partnership are traded on a
national stock exchange or in any other significant market. No liquid market
exists for interests in any of the partnerships. See Table 15 of Appendix A for
historical information about recent trades per $1,000 limited partner investment
in each partnership for the three months ended March 31, 2001 and the years
ended December 31, 2000 and 1999. The average quarterly cash distributions per
$1,000 limited partner investment in each partnership for 1999, 2000 and the
year-to-date in 2001 are set forth in Table 7 of Appendix A.


     On April 16, 2001, the last full trading day prior to the announcement of
the proposed merger of each partnership, Pioneer Parent common stock closed at
$17.27 per share. On , 2001, Pioneer Parent common stock closed at $ per share.




                            PIONEER PARENT COMMON
                            ---------------------
                                     STOCK
                                     -----
                                 MARKET PRICE
                                 ------------
                               HIGH        LOW
                              ------      ------
                                    
2001
     First quarter            $20.24      $15.45

2000
     Fourth quarter            20.63       12.44
     Third quarter             16.06       10.63
     Second quarter            15.63        9.00
     First quarter             10.75        6.75

1999
     Fourth quarter            11.50        7.63
     Third quarter             12.81        9.38
     Second quarter            13.19        7.06
     First quarter              9.75        5.00


     We urge the limited partners of each partnership to obtain current market
quotations prior to making any decision with respect to the merger of the
partnership.


                                      -62-
   73


                    INTERESTS OF PIONEER PARENT, PIONEER USA
                        AND THEIR DIRECTORS AND OFFICERS



     A number of conflicts of interest are inherent in the relationships among
each partnership, Pioneer Parent, Pioneer USA and their respective directors and
officers.


CONFLICTING DUTIES OF PIONEER USA, INDIVIDUALLY AND AS GENERAL PARTNER


     Pioneer USA, as general partner of each partnership, has a duty to manage
each partnership in the best interests of the limited partners. Pioneer USA also
has a duty to operate its business for the benefit of its sole stockholder,
Pioneer Parent. Consequently, Pioneer USA's duties to the limited partners of
each partnership may conflict with its duties to Pioneer Parent.



     The members of the board of directors of Pioneer USA have a duty to cause
Pioneer USA to manage each partnership in the best interests of the limited
partners. All members of the board of directors of Pioneer USA are officers of
Pioneer Parent and Pioneer USA. Thus, the members of the board of directors of
Pioneer USA have duties to operate Pioneer USA's business for the benefit of its
sole stockholder, Pioneer Parent, and, as officers of Pioneer Parent, to operate
Pioneer Parent's business in its best interests. Consequently, the duties of the
members of the board of directors of Pioneer USA to the limited partners may
conflict with the duties of those members to Pioneer Parent, Pioneer USA and
their stockholders.



     Neither Pioneer Parent nor Pioneer USA retained an independent
representative to negotiate on behalf of the limited partners of each
partnership because:


     o    neither the partnership agreement for any partnership nor any
          applicable law provides for any procedure to identify and select an
          independent representative, unless each limited partner of the
          partnership agrees to the independent representative;

     o    Pioneer USA, as sole or managing general partner of each partnership,
          still has its fiduciary duty to the limited partners; and

     o    it would be (1) cost-prohibitive to find one or more persons to
          represent the limited partners in all of the partnerships because no
          one other than Pioneer USA owns an interest in all of the partnerships
          and (2) impractical to have 46 independent representatives.

PIONEER USA'S EMPLOYEES PROVIDE SERVICES TO THE PARTNERSHIPS

     None of the partnerships currently has any employees. Each partnership
relies on Pioneer USA's personnel. Pioneer USA provides all management functions
on behalf of each partnership. Therefore, each partnership currently competes
with Pioneer USA for the time and resources of Pioneer USA's employees.

FINANCIAL INTERESTS OF DIRECTORS AND OFFICERS


     The directors and officers of Pioneer Parent and Pioneer USA have equity
interests in Pioneer Parent through stock ownership, stock options and other
stock-based compensation, but do not have financial or equity interests in any
partnership. See "Ownership of Partnership Interests" on page 64. The boards of
directors of Pioneer Parent and Pioneer USA believe that any economic benefit
their directors and officers may obtain from the merger of each partnership, or
the mergers of all of the partnerships in the aggregate, will be minimal, if
any, and will not result in a material economic benefit, if any, to their
directors and officers individually.


THE PARTNERSHIPS PAY OPERATOR FEES TO PIONEER USA

     Pioneer USA operates most of each partnership's wells. Each partnership has
entered into one or more standard industry operating agreements with Pioneer
USA. Those operating agreements establish the base fee paid by the partnership
to Pioneer USA for its lease operating services. That base fee adjusts annually
based on a rate established by the Council of Petroleum Accountants Society, or
COPAS, for the oil and gas industry.


                                      -63-
   74


                       OWNERSHIP OF PARTNERSHIP INTERESTS


     Pioneer Parent does not directly own any partnership interests in any
partnership. Pioneer Parent beneficially owns all of Pioneer USA's partnership
interests in each partnership. Table 6 of Appendix A to this document contains
the voting percentage as of March 31, 2001, of the outstanding limited
partnership interests for each partnership that are beneficially owned by
Pioneer USA as a limited partner. As of March 31, 2001, no person or entity
known by Pioneer USA beneficially owns more than 5% of the outstanding limited
partnership interests in any partnership, except in Parker & Parsley 81-I, Ltd.,
Parker & Parsley 82-I, Ltd. and Parker and Parsley 82-III, Ltd. In those
partnerships, Pioneer USA repurchased and now owns partnership interests
representing the following beneficial ownership percentages:


              Parker & Parsley 81-I, Ltd.                  5.84%
              Parker & Parsley 82-1, Ltd.                 10.73%
              Parker & Parsley 82-III, Ltd.                5.97%

Pioneer USA has sole investment and voting power with respect to partnership
interests it beneficially owns.


     Except as set forth above, none of Pioneer Parent, Pioneer USA, or, to the
knowledge of Pioneer USA, any of their directors or executive officers, or any
associate or majority-owned subsidiary of Pioneer Parent, Pioneer USA or any
such director or officer:


     o    beneficially owns any partnership interests of any partnership; or

     o    has effected any transactions in any partnership interests of any
          partnership during the past 60 days.


         TRANSACTIONS AMONG ANY PARTNERSHIP, PIONEER PARENT, PIONEER USA
                        AND THEIR DIRECTORS AND OFFICERS



     Except as described in this document, there have not been any transactions,
negotiations or material contacts between Pioneer Parent, Pioneer USA, any of
their respective subsidiaries, or, to the knowledge of Pioneer Parent and
Pioneer USA, any director or executive officer of Pioneer Parent or Pioneer USA
or any associate of any such persons, on the one hand, and any partnership or
any of its general partners, including Pioneer USA, directors, officers or
affiliates, on the other hand, that are required to be disclosed pursuant to the
rules and regulations of the SEC. Except as described in this document, none of
Pioneer Parent, Pioneer USA, or, to the knowledge of Pioneer Parent and Pioneer
USA, any director or executive officer of Pioneer Parent or Pioneer USA, has any
agreement, arrangement or understanding with any other person with respect to
any securities of any partnership.



     During March 2001, Pioneer Parent offered to acquire all of the direct oil
and gas interests owned by some former officers and employees of Pioneer Parent
and Pioneer USA in properties in which Pioneer Parent and Pioneer USA own
interests. The merger value for the direct oil and gas interests was equal to
the present value of estimated future net revenues from the oil and gas reserves
attributable to the interests, as of March 31, 2001. In determining the present
value, Pioneer Parent and Pioneer USA used (1) a five-year NYMEX futures price
for oil and gas as of March 2001 with prices held constant after year five at
the year five price, less standard industry adjustments, (2) historical
operating costs adjusted only for those items affected by commodity prices, such
as production taxes and ad valorem taxes, and (3) a 13.5% discount rate. The
consideration offered in the purchases of the direct oil and gas interests was
all cash since offering and registering Pioneer Parent common stock in those
purchases was cost-prohibitive due to the small size of such transactions.



     Additionally, in December 2000, Pioneer Parent received the approval of the
partners of 13 employee limited partnerships to merge with Pioneer USA for total
merger consideration of $2.0 million. Of the total merger consideration, $0.3
million was paid to current Pioneer Parent employees. The merger value of each
employee partnership was equal to the sum of the present value of estimated
future net revenues from the partnership's estimated oil and gas reserves and
its net working capital, in each case as of September 30, 2000, less the cash
distributions on October 15, 2000 and November 15, 2000, by that partnership to
its partners. In determining the present value, Pioneer Parent and Pioneer USA
used (1) a five-year NYMEX futures price for oil and gas as of August 25, 2000
with prices held constant after year five at the year five price, less standard
industry adjustments, (2) historical operating costs adjusted only for those
items affected by commodity prices, such as production taxes and ad valorem
taxes, and (3) a 13.5% discount rate. Using the same parameters as described
above, Pioneer Parent purchased all of the direct oil and gas interests held by
Scott D. Sheffield, its chairman of the board of directors and chief executive
officer, for $0.2 million during October 2000. The consideration paid in the
mergers of the employee limited partnerships and the purchase of Mr. Sheffield's
direct oil and gas interests was all cash. As with the purchases of the direct
oil and gas interests described above, offering and registering Pioneer Parent
common stock in these transactions was cost-prohibitive due to the small size of
such transactions.


     If you approve the merger of each partnership in which you own an interest,
there are various ways that Pioneer USA may use the properties. Pioneer USA may
continue to operate the properties, it may sell the properties to third


                                      -64-
   75


parties, including a royalty trust, or it may spin-off the properties to its
stockholder. Although Pioneer USA plans to operate the properties in the
immediate future following completion of the merger of each partnership, it has
not decided how to use the properties in the long-term.


                                      -65-
   76


                                   MANAGEMENT


PIONEER PARENT



     The following information sets forth the age, business experience during
the past five years, positions and offices with Pioneer Parent, and periods of
service of each director and executive officer of Pioneer Parent.





            NAME            AGE                         POSITION
            ----            ---                         --------
                                  
Scott D. Sheffield           48         Chairman of the Board of Directors, President and Chief
                                        Executive Officer
Timothy L. Dove              44         Executive Vice President and Chief Financial Officer
Dennis E. Fagerstone         52         Executive Vice President
Mark L. Withrow              53         Executive Vice President, General Counsel and Secretary
Danny L. Kellum              46         Executive Vice President -- Domestic Operations
James R. Baroffio            69         Director
R. Hartwell Gardner          66         Director
James L. Houghton            70         Director
Jerry P. Jones               69         Director
Charles E. Ramsey, Jr.       64         Director




     Scott D. Sheffield. Mr. Sheffield, a distinguished graduate of the
University of Texas with a Bachelor of Science degree in Petroleum Engineering,
has been the Chairman of the Board of Directors of Pioneer Parent since August
1999 and the President and Chief Executive Officer of Pioneer Parent since
August 1997. Mr. Sheffield was the Chairman of the Board of Directors, President
and Chief Executive Officer of Parker & Parsley Petroleum Company from October
1990 until August 1997. He was the President and a director of Parker & Parsley
Petroleum Company from May 1990 until October 1990. Mr. Sheffield was the sole
director of Parker & Parsley Petroleum Company from May 1990 until October 1990.
Mr. Sheffield joined Parker & Parsley Development Company, a predecessor of
Parker & Parsley Petroleum Company, as a petroleum engineer in 1979. Mr.
Sheffield served as Vice President-- Engineering of Parker & Parsley Development
Company from September 1981 until April 1985, when he was elected President and
a director. In March 1989, Mr. Sheffield was elected Chairman of the Board of
Directors and Chief Executive Officer of Parker & Parsley Development Company.
Before joining Parker & Parsley Development Company 's predecessor, Mr.
Sheffield was employed as a production and reservoir engineer for Amoco
Production Company.



     Timothy L. Dove. Mr. Dove, a graduate of Massachusetts Institute of
Technology with a Bachelor of Science degree in Mechanical Engineering and the
University of Chicago with an M.B.A., has been Executive Vice President and
Chief Financial Officer of Pioneer Parent since February 2000. He was Executive
Vice President-- Business Development of Pioneer Parent from August 1997 until
February 2000. Mr. Dove joined Parker & Parsley Petroleum Company in May 1994 as
Vice President-- International and was promoted to Senior Vice President--
Business Development in October 1996, in which position he served until August
1997. Before joining Parker & Parsley Petroleum Company, Mr. Dove was employed
with Diamond Shamrock Corp., and its successor, Maxus Energy Corp., in various
capacities in international exploration and production, marketing, refining, and
planning and development.



     Dennis E. Fagerstone. Mr. Fagerstone, a graduate of the Colorado School of
Mines with a B.S. in Petroleum Engineering, has been an Executive Vice President
of Pioneer Parent since August 1997. Mr. Fagerstone served as Executive Vice
President and Chief Operating Officer of MESA Inc. from March 1997 until August
1997. Mr. Fagerstone served as Senior Vice President and Chief Operating Officer
of MESA Inc. from October 1996 to February 1997, and served as Vice President--
Exploration and Production of MESA Inc. from May 1991 to October 1996. Mr.
Fagerstone served as Vice President-- Operations of MESA Inc. from June 1988
until May 1991.



     Mark L. Withrow. Mr. Withrow, a graduate of Abilene Christian University
with a Bachelor of Science degree in Accounting and Texas Tech University with a
J.D. degree, has been the Executive Vice President, General Counsel and
Secretary of Pioneer Parent since August 1997. He served as Vice President--
General Counsel of Parker & Parsley Petroleum Company from February 1991 until
January 1995, and served as Senior Vice President and General Counsel of Parker
& Parsley Petroleum Company from January 1995 until August 1997. He was Parker &
Parsley Petroleum Company's Secretary from August 1992 until August 1997. Mr.
Withrow joined Parker & Parsley Development Company in January 1991. Before
joining Parker & Parsley Development Company, Mr. Withrow was the managing
partner of the law firm of Turpin, Smith, Dyer, Saxe & MacDonald, Midland,
Texas.



     Danny L. Kellum. Mr. Kellum, a graduate of Texas Tech University with a
Bachelor of Science degree in Petroleum Engineering in 1979, has been Executive
Vice President-- Domestic Operations of Pioneer Parent since May 2000. From
January 2000 until May 2000, Mr. Kellum served as Vice President - Domestic
Operations. From August 1997 until December 1999, Mr. Kellum served as Vice
President-- Permian Division. Mr. Kellum served as Spraberry District Manager
for Parker & Parsley Petroleum Company from 1989 until 1994 and as Vice
President of



                                      -66-
   77


the Spraberry and Permian Divisions for Parker & Parsley Petroleum Company from
1994 until August 1997. He joined Parker & Parsley Petroleum Company in 1981 as
Operations Engineer after a brief career with Mobil Oil Corporation.



     James R. Baroffio. Dr. Baroffio received a B.A. in Geology at the College
of Wooster, Ohio, an M.S. in Geology at Ohio State University, and a Ph.D. in
Geology at the University of Illinois. Before becoming a director of Pioneer
Parent in December 1997, Dr. Baroffio enjoyed a long career with Standard Oil
Company of California, the predecessor of Chevron Corporation, where he served
as President, Chevron Research and Technology Center from 1980 to 1985 and
eventually retired as President of Chevron Canada Resources in 1994. Dr.
Baroffio was a member of the Board of Directors of the Rocky Mountain Oil & Gas
Association and Chairman of the U.S. National Committee of the World Petroleum
Congress. His community leadership positions included membership on the Board of
Directors of Glenbow Museum and the Nature Conservancy of Canada, as well as
serving as President of the Alberta Nature Conservancy.



     R. Hartwell Gardner. Mr. Gardner, a graduate of Colgate University with a
Bachelor of Arts degree in Economics and Harvard University with an M.B.A.,
became a director of Pioneer Parent in August 1997. He served as a director of
Parker & Parsley Petroleum Company from November 1995 until August 1997. Until
his retirement in September 1995, Mr. Gardner was the Treasurer of Mobil Oil
Corporation and Mobil Corporation from 1974 and 1976, respectively. Mr. Gardner
is a member of the Financial Executives Institute of which he served as Chairman
in 1986/1987 and is a Director of Oil Investment Corporation Ltd. and Oil
Casualty Investment Corporation Ltd., Pembroke, Bermuda.



     James L. Houghton. Mr. Houghton is a certified public accountant and a
graduate of Kansas University with a Bachelor of Science degree in Accounting,
as well as a Bachelor of Laws degree. Mr. Houghton has served as a director of
Pioneer Parent since August 1997, and as a director of Parker & Parsley
Petroleum Company from October 1991 until August 1997. Until his retirement in
September 1991, Mr. Houghton was the lead oil and gas tax specialist for the
accounting firm of Ernst & Young LLP, was a member of Ernst & Young's National
Energy Group, and had served as its Southwest Regional Director of Tax. Mr.
Houghton is a member of the American Institute of Certified Public Accountants,
a member of the Oklahoma Society of Certified Public Accountants, a former
Chairman of its Federal and Oklahoma Taxation Committee and past President of
the Oklahoma Institute of Taxation. He has also served as a Director for the
Independent Petroleum Association of America and as a member of its Tax
Committee.



     Jerry P. Jones. Mr. Jones earned a Bachelor of Science degree from West
Texas State College in 1953 and a Bachelor of Law degree from the University of
Texas School of Law in 1959. Mr. Jones has served as a director of Pioneer
Parent since August 1997, and as a director of Parker & Parsley Petroleum
Company from May 1991 until August 1997. Mr. Jones has been an attorney with the
law firm of Thompson & Knight, P.C., Dallas, Texas, since September 1959 and was
a shareholder in that firm until January 1998, when he retired and became of
counsel to the firm. Mr. Jones specialized in civil litigation, especially in
the area of energy disputes.



     Charles E. Ramsey, Jr. Mr. Ramsey is a graduate of the Colorado School of
Mines with a Petroleum Engineering degree and a graduate of the Smaller Company
Management program at the Harvard Graduate School of Business Administration.
Mr. Ramsey has served as a director of Pioneer Parent since August 1997. Mr.
Ramsey served as a director of Parker & Parsley Petroleum Company from October
1991 until August 1997. Since October 1991, he has operated Ramsey Energy LLC,
an independent management and financial consulting firm. From June 1958 until
June 1986, Mr. Ramsey held various engineering and management positions in the
oil and gas industry and, for six years before October 1991, was a Senior Vice
President in the Corporate Finance Department of Dean Witter Reynolds Inc. in
Dallas, Texas. His industry experience includes 12 years of senior management
experience in the positions of President, Chief Executive Officer and Executive
Officer and Executive Vice President of May Petroleum Inc. Mr. Ramsey is also a
former director of MBank Dallas, the Dallas Petroleum Club and Lear Petroleum
Corporation.





PIONEER USA

     The following information sets forth the age, business experience during
the past five years, positions and offices with Pioneer USA, and periods of
service of each director and executive officer of Pioneer USA.



         NAME                AGE                   POSITION
         ----                ---                   --------
                                  
Scott D. Sheffield           48         President
Timothy L. Dove              44         Director, Executive Vice President and
                                        Chief Financial Officer
Dennis E. Fagerstone         52         Director and Executive Vice President
Mark L. Withrow              53         Director, Executive Vice President,
                                        General Counsel and Secretary
Danny L. Kellum              46         Director and Executive Vice President



                                      -67-
   78



     Scott D. Sheffield. Mr. Sheffield has been the President of Pioneer USA
since August 1997 and served as the Chairman of the Board of Directors of
Pioneer USA from August 1997 until June 1999. He served as a Director of Pioneer
USA's predecessor, Parker & Parsley Petroleum USA, Inc., from January 1991 until
August 1997. He was an Executive Vice President of Parker & Parsley Petroleum
USA, Inc. from December 1995 until August 1997. He was the President of Parker &
Parsley Petroleum USA, Inc. from December 1993 until December 1995. Mr.
Sheffield was President and Chief Executive Officer of Parker & Parsley
Petroleum USA, Inc. from January 1991 until December 1993. Mr. Sheffield's other
business experience and biographical information are set forth above under
"Management-- Pioneer Parent."



     Timothy L. Dove. Mr. Dove has been a Director of Pioneer USA since August
1997 and has been Executive Vice President and Chief Financial Officer of
Pioneer USA since February 2000. He was the Executive Vice President-- Business
Development of Pioneer USA from August 1997 until February 2000. He served as a
Director of Parker & Parsley Petroleum USA, Inc. from June 1997 until August
1997. He was a Senior Vice President of Parker & Parsley Petroleum USA, Inc.
from October 1996 until August 1997. He was a Vice President of Parker & Parsley
Petroleum USA, Inc. from December 1995 until October 1996. Mr. Dove's other
business experience and biographical information are set forth above under
"Management-- Pioneer Parent."



     Dennis E. Fagerstone. Mr. Fagerstone has been a Director of Pioneer USA
since August 1997 and an Executive Vice President of Pioneer USA since August
1997. Mr. Fagerstone's other business experience and biographical information
are set forth above under "Management-- Pioneer Parent."



     Mark L. Withrow. Mr. Withrow has been a Director of Pioneer USA since
August 1997. He became an Executive Vice President, the General Counsel and the
Secretary of Pioneer USA in August 1997. He served as a Director of Parker &
Parsley Petroleum USA, Inc. from January 1996 until August 1997. He was a Senior
Vice President and the Secretary of Parker & Parsley Petroleum USA, Inc. from
January 1995 until August 1997. He was a Vice President and the Secretary of
Parker & Parsley Petroleum USA, Inc. from December 1993 until January 1995. He
was a Vice President of Parker & Parsley Petroleum USA, Inc. from January 1991
until December 1993. Mr. Withrow's other business experience and biographical
information are set forth above under "Management-- Pioneer Parent."



     Danny L. Kellum. Mr. Kellum has been a Director of Pioneer USA since
February 2000, and has been Executive Vice President of Pioneer USA since May
2000. He served as Vice President -- Domestic Operations of Pioneer USA from
January 2000 until May 2000, as Vice President -- Permian Division of Pioneer
USA from April 1998 until December 1999 and as Vice President -- Spraberry
Division of Pioneer USA from December 1997 until March 1998. Mr. Kellum's other
business experience and biographical information are set forth above under
"Management -- Pioneer Parent."



                                      -68-
   79


                                 PIONEER PARENT


     Pioneer Parent is a large independent exploration and production company
with total proved reserves equivalent to 3.8 trillion cubic feet of natural gas,
or 628 million barrels of oil. Pioneer Parent's proved reserves are balanced
equally between natural gas and oil, and Pioneer Parent has a
reserves-to-production ratio of 14 years. Three core areas in the United States
comprise 67% of Pioneer Parent's reserve base: the Hugoton gas field, the West
Panhandle gas field, and the Spraberry oil and natural gas field. Pioneer Parent
also has domestic properties in East Texas, the Gulf Coast, and the offshore
Gulf of Mexico as well as a significant international presence through its
properties in Argentina, Canada, South Africa, and Gabon.



     Pioneer Parent seeks to increase net asset value and production by
combining lower risk development drilling with higher risk exploration activity.
Pioneer Parent has identified over 1,700 development drilling locations on its
properties in the U.S., Argentina and Canada. Approximately 76% of the
identified 1,700 development drilling locations have proved undeveloped reserves
attributable to them. Pioneer Parent's exploration program is focused in the
deepwater Gulf of Mexico, the Gulf Coast shelf, South Africa and Gabon. Pioneer
Parent expects significant new production from the deepwater Gulf of Mexico and
South Africa in 2002 and 2003 as it builds on its recent exploration successes
in those areas. The production from Pioneer Parent's long-lived reserves in the
Spraberry, Hugoton and West Panhandle fields are expected to provide stable cash
flows to fund Pioneer Parent's development and exploration activities.



     During 2000, Pioneer Parent spent $340 million for capital expenditures to
add 437 billion cubic feet of natural gas equivalent reserves. As a consequence,
in 2000 Pioneer Parent replaced 167% of its production at an acquisition and
finding cost of $.78 per Mcf equivalent. Pioneer Parent's acquisition and
finding cost is the result obtained by dividing total costs incurred by the sum
of revisions of previous estimates, purchases of minerals-in-place and new
discoveries and extensions. Pioneer Parent drilled 296 wells with 90% success
worldwide, including 83 exploration and extension wells with 73% success.



     For 2001, Pioneer Parent has budgeted $430 million of capital expenditures,
a 26% increase over 2000 capital expenditures but less than expected available
cash flow. Approximately 73% of the 2001 capital expenditure budget is for
development activities with the remaining 27% for exploration. Pioneer Parent
plans to drill approximately 460 development wells and 26 exploratory wells in
its 2001 program, and approximately 65% of the capital expenditures will be for
drilling activities in the U.S.


KEY PROJECTS TO INCREASE PRODUCTION


     Pioneer Parent expects to increase its production of oil and gas from
current levels by 25% to 30% on a gas equivalent basis by early to mid 2003,
primarily from four projects. The production increases anticipated from the four
projects are derived from currently booked proved undeveloped reserves. The
projects in general build on Pioneer Parent's recent exploration successes.



     o    The Canyon Express project is a joint development of three deepwater
          Gulf of Mexico discoveries, including Pioneer Parent's Aconcagua and
          Camden Hills fields. The project is being developed with a capacity to
          deliver 500 million cubic feet of natural gas per day by the summer of
          2002. Pioneer Parent owns an 18% interest in the Canyon Express
          project and expects that production from the project will increase
          Pioneer Parent's North American natural gas production by 30% from
          current levels.



     o    Pioneer Parent's first well in offshore South Africa confirmed the
          presence of commercial oil reserves and resulted in Pioneer Parent's
          plans to develop the Sable oil field. First production from the field
          is expected in late 2002 or early 2003 at daily rates of 25 to 30
          thousand barrels per day. Pioneer Parent has a 35% working interest in
          the field, and production from the project is expected to increase
          Pioneer Parent's total oil production by more than 20%. Pioneer Parent
          has also discovered oil and natural gas at its Boomslang prospect in
          offshore South Africa and plans a second well on the prospect later in
          2001.



     o    The Devils Tower discovery was Pioneer Parent's second in the
          deepwater Gulf of Mexico. The oil field has been successfully
          appraised, and development plans call for first production in early
          2003 with additional drilling planned this year. Pioneer Parent has a
          25% working interest in the field, and production from the field is
          expected to increase Pioneer Parent's total oil production by
          approximately 20% from current levels.



     o    In the East Texas Bossier natural gas play, Pioneer Parent holds
          interests in over 130,000 acres and plans to drill or participate in
          over 35 wells during 2001. The play's strong initial natural gas flow
          rates are expected to provide significant new production growth.



                                      -69-
   80


MORE INFORMATION


     A more complete description of Pioneer Parent and its business is found in
the reports that Pioneer Parent files with the SEC. Please see "Where You Can
Find More Information" on the inside front cover page of this document. Pioneer
Parent's business, and its expectations about its future, are subject to many
risks. Please also read "Risks Associated with an Investment in Pioneer Parent"
under the caption "Risk Factors" beginning on page 17 of this document.




                                      -70-
   81


                                THE PARTNERSHIPS

GENERAL


     Pioneer USA's predecessor, Parker & Parsley Petroleum USA, Inc. or its
predecessors or affiliates, sponsored each partnership. As a result of the
merger of Parker & Parsley Petroleum Company and MESA Inc. to form Pioneer
Parent on August 7, 1997, Pioneer USA became the managing or sole general
partner of each partnership.



     Appendix A to this document sets forth information about each partnership,
including proved reserves as of December 31, 2000, estimated reserves as of
March 31, 2001, oil and gas production, average sales prices and production
costs, productive wells and developed acreage, and historical cash
distributions. In addition, the supplement for each partnership constitutes an
integral part of this document. You should read Appendix A and the supplement
carefully in their entirety.


THE DRILLING PARTNERSHIPS

     The drilling partnerships consist of the following 43 limited partnerships
that were formed from 1981 through 1991:



          NAME                                          STATE OF FORMATION
          ----                                          ------------------
                                                     
Parker & Parsley 81-I, Ltd.                                   Texas
Parker & Parsley 81-II, Ltd.                                  Texas
Parker & Parsley 82-I, Ltd.                                   Texas
Parker & Parsley 82-II, Ltd.                                  Texas
Parker & Parsley 82-III, Ltd.                                 Texas
Parker & Parsley 83-A, Ltd.                                   Texas
Parker & Parsley 83-B, Ltd.                                   Texas
Parker & Parsley 84-A, Ltd.                                   Texas
Parker & Parsley 85-A, Ltd.                                   Texas
Parker & Parsley 85-B, Ltd.                                   Texas
Parker & Parsley Private Investment 85-A, Ltd.                Texas
Parker & Parsley Selected 85 Private Investment, Ltd.         Texas
Parker & Parsley 86-A, Ltd.                                   Texas
Parker & Parsley 86-B, Ltd.                                   Texas
Parker & Parsley 86-C, Ltd.                                   Texas
Parker & Parsley Private Investment 86, Ltd.                  Texas
Parker & Parsley 87-A Conv., Ltd.                             Texas
Parker & Parsley 87-A, Ltd.                                   Texas
Parker & Parsley 87-B Conv., Ltd.                             Texas
Parker & Parsley 87-B, Ltd.                                   Texas
Parker & Parsley Private Investment 87, Ltd.                  Texas
Parker & Parsley 88-A Conv., L.P.                           Delaware
Parker & Parsley 88-A, L.P.                                 Delaware
Parker & Parsley 88-B Conv., L.P.                           Delaware
Parker & Parsley 88-B L.P.                                  Delaware
Parker & Parsley 88-C Conv., L.P.                           Delaware
Parker & Parsley 88-C, L.P.                                 Delaware
Parker & Parsley Private Investment 88, L.P.                Delaware
Parker & Parsley 89-A Conv., L.P.                           Delaware
Parker & Parsley 89-A, L.P.                                 Delaware
Parker & Parsley 89-B Conv., L.P.                           Delaware
Parker & Parsley 89-B, L.P.                                 Delaware
Parker & Parsley Private Investment 89, L.P.                Delaware
Parker & Parsley 90-A Conv., L.P.                           Delaware
Parker & Parsley 90-A, L.P.                                 Delaware
Parker & Parsley 90-B Conv., L.P.                           Delaware
Parker & Parsley 90-B, L.P.                                 Delaware
Parker & Parsley 90-C Conv., L.P.                           Delaware
Parker & Parsley 90-C, L.P.                                 Delaware
Parker & Parsley Private Investment 90, L.P.                Delaware



                                      -71-
   82



          NAME                                          STATE OF FORMATION
          ----                                          ------------------
                                                     
Parker & Parsley 90 Spraberry Private Development, L.P.     Delaware
Parker & Parsley 91-A, L.P.                                 Delaware
Parker & Parsley 91-B, L.P.                                 Delaware


     Each drilling partnership was formed to establish long-lived oil and gas
reserves primarily by drilling low-risk development wells in the Spraberry field
of the Permian Basin of West Texas. The oil and gas properties of each drilling
partnership consist primarily of leasehold interests in producing properties
located in Texas. The partners of a drilling partnership received a tax benefit
from drilling activities in the partnership's first year. Subsequently, each
drilling partnership has regularly distributed its net cash flow. As of the date
of this document, each drilling partnership has expended all of its initial
capital contributions.

     For a discussion of transactions between each drilling partnership and
Pioneer USA, see the notes to the financial statements of each drilling
partnership included in the supplement for the partnership.

THE INCOME PARTNERSHIPS

     The income partnerships consist of the following three limited partnerships
that were formed in 1987 and 1988:



          NAME                                          STATE OF FORMATION
          ----                                          ------------------
                                                     
Parker & Parsley Producing Properties 87-A, Ltd.              Texas
Parker & Parsley Producing Properties 87-B, Ltd.              Texas
Parker & Parsley Producing Properties 88-A, L.P.           Delaware


     The primary objective of each income partnership was to acquire long-lived,
producing oil and gas properties in the Spraberry Field of the Permian Basin of
West Texas. Subsequently, each income partnership has regularly distributed its
net cash flow. As of the date of this document, each income partnership has
expended all of its initial capital contributions.

     For a discussion of transactions between each income partnership and
Pioneer USA, see the notes to the financial statements of each income
partnership included in the supplement for the partnership.



                                      -72-
   83

                COMPARISON OF RIGHTS OF STOCKHOLDERS AND PARTNERS

GENERAL


     The rights of Pioneer Parent stockholders are currently governed by the
Delaware General Corporation Law and the certificate of incorporation and bylaws
of Pioneer Parent. The rights of the limited partners of each partnership are
currently governed by the Delaware Revised Uniform Limited Partnership Act or
the Texas Revised Limited Partnership Act and, in either case, the partnership
agreement of the partnership. Accordingly, on completion of the merger of each
partnership, the rights of Pioneer Parent stockholders and of limited partners
who become Pioneer Parent stockholders in the merger of their partnerships will
be governed by the Delaware General Corporation Law, Pioneer Parent's
certificate of incorporation and Pioneer Parent's bylaws. The following is a
summary of the material differences between the current rights of Pioneer Parent
stockholders and those of the limited partners of each partnership.



     The following summary of the material differences between the Pioneer
Parent certificate of incorporation, the Pioneer Parent bylaws and the
partnership agreement for each partnership may not contain all the information
that is important to you. To review all provisions and differences of such
documents in full detail, please read the full text of these documents, the
Delaware General Corporation Law, the Delaware Revised Uniform Limited
Partnership Act and the Texas Revised Limited Partnership Act. Copies of the
Pioneer Parent certificate of incorporation, the Pioneer Parent bylaws and the
partnership agreement for each partnership in which you own an interest will be
sent to you upon request. For information on how these documents may be
obtained, see "Where You Can Find More Information" on the inside front cover
page of this document.



     Pioneer Parent's certificate of incorporation and bylaws will not be
amended in conjunction with the merger of any partnership.


SUMMARY COMPARISON OF TERMS OF SHARES OF PIONEER PARENT COMMON STOCK AND
PARTNERSHIP INTERESTS




----------------------------------------------------------------------------------------------------------------------
                          SHARES                                              PARTNERSHIP INTERESTS
----------------------------------------------------------------------------------------------------------------------
                                                          
                                             LIQUIDITY AND MARKETABILITY
----------------------------------------------------------------------------------------------------------------------
Shares of Pioneer Parent common stock are generally freely   The partnership interests of each partnership may not
transferable.  The shares of Pioneer Parent common stock     be transferred if, in the opinion of counsel to the
that are currently outstanding are traded on the New York    partnership, (1) such transfers would result in the
Stock Exchange and the Toronto Stock Exchange, and the       termination of the partnership for federal income tax
shares of Pioneer Parent common stock to be issued in the    purposes under Section 708 of the Internal Revenue
merger of each participating partnership have been           Code, or (2) such transfers may not be effected without
approved for listing on the New York Stock Exchange and      registration under the Securities Act of 1933 or would
the Toronto Stock Exchange upon official notice of           result in the violation of any applicable state
issuance.                                                    securities laws.  Clause (1) is not applicable to
                                                             Parker & Parsley 85-A, Ltd., Parker & Parsley 85-B,
                                                             Ltd., Parker & Parsley Private Investment 85-A, Ltd.,
                                                             Parker & Parsley Selected 85 Private Investment, Ltd.,
                                                             Parker & Parsley Private Investment 86, Ltd., Parker &
                                                             Parsley 87-A Conv., Ltd., Parker & Parsley 87-A, Ltd.,
                                                             Parker & Parsley 87-B Conv., Ltd. and Parker & Parsley
                                                             87-B, Ltd. and Parker & Parsley Private Investment 87,
                                                             Ltd. In addition, no transferee of a partnership
                                                             interest has the right to become a substitute limited
                                                             partner unless, among other things, such substitution
                                                             is approved by Pioneer USA, who may grant or withhold
                                                             such consent in its absolute discretion.  In view of
                                                             the foregoing restrictions, it was never intended that
                                                             the partnership interests would be actively traded. No
                                                             broad-based secondary market for the partnership
                                                             interests of any partnership exists.
----------------------------------------------------------------------------------------------------------------------




                                      -73-
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----------------------------------------------------------------------------------------------------------------------
                          SHARES                                              PARTNERSHIP INTERESTS
----------------------------------------------------------------------------------------------------------------------
                                                          
                                                RIGHTS OF REPURCHASE
----------------------------------------------------------------------------------------------------------------------
Pioneer Parent's stockholders have no right to present       Within the time periods specified in the partnership
their shares of Pioneer Parent common stock for repurchase   agreements of Parker & Parsley 82-I, Ltd., Parker &
by Pioneer Parent or any other person.                       Parsley 82-II, Ltd., Parker & Parsley 82-III, Ltd.,
                                                             Parker & Parsley 83-A, Ltd., Parker & Parsley 83-B,
                                                             Ltd. and Parker & Parsley 84-A, Ltd., a limited partner
                                                             of any of those partnerships may tender all or, subject
                                                             to some limitations, part of his partnership interests
                                                             in the partnership to Pioneer USA for repurchase in
                                                             accordance with the partnership agreement for the
                                                             partnership.  See "Risk Factors -- Risk Factors Relating
                                                             to the Merger of Each Partnership -- Repurchase Rights
                                                             Terminate on Completion of the Mergers."  A comparison
                                                             of the merger value for each of these partnerships and
                                                             the repurchase prices in 2001 is set forth in Table 8
                                                             of Appendix A.

----------------------------------------------------------------------------------------------------------------------
                                MANAGEMENT, MANAGEMENT LIABILITY AND INDEMNIFICATION
----------------------------------------------------------------------------------------------------------------------

Pioneer Parent is managed by a board of directors elected    Each of the partnerships is managed by Pioneer USA,
by its stockholders.  Under Delaware law, the directors      which generally has exclusive authority over each of
are accountable to Pioneer Parent and its stockholders as    the partnership's operations.  The limited partners may
fiduciaries and are required to perform their duties (1)     not participate in management of the partnerships.
in good faith, (2) in a manner believed to be in the best    Under Delaware and Texas law, Pioneer USA and any
interests of Pioneer Parent and its stockholders and (3)     nonmanaging general partners of any of the partnerships
with such care, including reasonable inquiry, as an          are accountable to the partnership as fiduciaries and
ordinarily prudent person in a like position would use       consequently are required to exercise good faith and
under similar circumstances.  The liability of the           integrity in all of their dealings with respect to the
directors is limited pursuant to the provisions of           affairs of the partnership.  Under Texas or Delaware
Delaware law and Pioneer Parent's certificate of             law, as applicable, Pioneer USA and any nonmanaging
incorporation, which limits a director's liability for       general partners of any of the partnerships have
monetary damages to Pioneer Parent or its stockholders for   liability for the payment of partnership obligations
breach of the director's duty of care, where a director      and debts, unless limitations upon such liability are
fails to exercise sufficient care in carrying out the        expressly stated in the obligation.  The partnership
responsibilities of office.  Such provisions, however,       agreement of each partnership provides generally that
would not protect a director for (1) a breach of duty of     Pioneer USA, any nonmanaging general partners of the
loyalty, (2) intentional misconduct or knowing violations    partnership and, in some cases, their affiliates will
of law, (3) unlawful dividend payments or redemption of      be indemnified for losses relating to acts performed or
stock, or (4) any transaction in which the director          omitted to be performed in good faith and in the best
derived an improper personal benefit. Such provisions do     interests of the partnership; provided that the conduct
not foreclose any other remedy which might be available to   of Pioneer USA, any such nonmanaging general partner or
Pioneer Parent or its stockholders.  Pioneer Parent's        affiliate, as applicable, did not constitute negligence
certificate of incorporation and Delaware law provide        or misconduct.  Pioneer USA and any nonmanaging general
broad indemnification rights to directors and officers who   partners of the partnership may be removed by an
                                                             affirmative vote of limited partners holding a majority
     o   act in good faith,                                  of the outstanding  limited partnership interests in
                                                             the partnership; provided, that an opinion of counsel
     o   in a manner reasonably believed to be in or not     to the limited partners and acceptable to the
         opposed to the best interests of Pioneer Parent     partnership is delivered to the partnership to the
         and,                                                effect that the exercise of such rights by the limited
                                                             partners (1) will not result in the loss of the limited
     o   with respect to criminal actions or proceedings,    partners' limited liability and (2) will not adversely
         without reasonable cause to believe their conduct   affect the tax status of the partnership, Pioneer USA
         was unlawful.                                       or the other partners.

----------------------------------------------------------------------------------------------------------------------




                                      -74-
   85




----------------------------------------------------------------------------------------------------------------------
                          SHARES                                              PARTNERSHIP INTERESTS
----------------------------------------------------------------------------------------------------------------------
                                                          
Pioneer Parent's certificate of incorporation also
requires Pioneer Parent to indemnify its officers and
directors under some circumstances for expenses or
liabilities incurred as a result of litigation. In
addition, Pioneer Parent's certificate of incorporation
authorizes Pioneer Parent to advance expenses incurred in
the defense of its directors and officers.  Pioneer Parent
intends to take full advantage of those provisions and has
entered into agreements with Pioneer Parent's directors
and officers indemnifying them to the fullest extent
permitted by Delaware law.

----------------------------------------------------------------------------------------------------------------------
                                               MANAGEMENT COMPENSATION
----------------------------------------------------------------------------------------------------------------------
The board of directors of Pioneer Parent appoints officers   Each partnership reimburses Pioneer USA for its general
to serve at the discretion of the board of directors.  The   and administrative expenses.
board of directors of Pioneer Parent determines the
officer salaries and incentive compensation; provided,
that the board of directors of Pioneer Parent may delegate
the power to determine such compensation to the chairman
of the board, the president or any committee of the board
of directors.
----------------------------------------------------------------------------------------------------------------------
                                                 MANAGEMENT CONTROL
----------------------------------------------------------------------------------------------------------------------
Pioneer Parent's board of directors has exclusive control    Under the partnership agreement of each partnership,
over Pioneer Parent's business and affairs subject only to   Pioneer USA is generally vested with all management
the restrictions in Pioneer Parent's certificate of          authority to manage, control, administer and operate
incorporation and bylaws.  Pioneer Parent's stockholders     the business, properties and affairs of the
have the right to elect members of the board of directors    partnership, including authority and responsibility for
by a plurality vote at each annual meeting of the            overseeing all executive, supervisory and
stockholders.  The directors are accountable to Pioneer      administrative services rendered to the partnership.
Parent and its subsidiaries as fiduciaries.                  Pioneer USA and any nonmanaging general partners have
                                                             the right to continue to serve in such capacity unless
                                                             Pioneer USA or such nonmanaging general partner is
                                                             removed upon the affirmative vote of limited partners
                                                             holding a majority of the outstanding limited
                                                             partnership interests in the partnership; provided,
                                                             that an opinion of counsel to the limited partners, and
                                                             acceptable to the partnership, is delivered to the
                                                             partnership to the effect that the exercise of such
                                                             rights by the limited partners (1) will not result in
                                                             the loss of the limited partners' limited liability and
                                                             (2) will not adversely affect the tax status of the
                                                             partnership, Pioneer USA or the other partners.  The
                                                             limited partners of each partnership have no right to
                                                             participate in the management and control of the
                                                             partnership and have no voice in the partnership's
                                                             affairs except for some limited matters that may be
                                                             submitted to a vote of the limited partners under the
                                                             terms of the partnership agreement of the partnership.
                                                             See "Voting Rights and Amendments" below.  Pioneer USA
                                                             is accountable as a fiduciary to each partnership.
----------------------------------------------------------------------------------------------------------------------




                                      -75-
   86





----------------------------------------------------------------------------------------------------------------------
                          SHARES                                              PARTNERSHIP INTERESTS
----------------------------------------------------------------------------------------------------------------------
                                                          
                                            VOTING RIGHTS AND AMENDMENTS
----------------------------------------------------------------------------------------------------------------------
Pioneer Parent's certificate of incorporation provides       Generally, meetings of each partnership may be called
that (1) stockholders of Pioneer Parent may act only at      by Pioneer USA or by limited partners owning at least
annual or special meetings of stockholders and not by        10% of the outstanding limited partnership interests.
written consent, (2) Pioneer Parent will hold an annual      The limited partners may conduct any partnership
meeting each calendar year at which its stockholders will    business at such meeting which is permitted under the
elect directors, (3) special meetings of stockholders may    partnership agreement for such partnership and is
be called only by the board of directors, and (4) only       specified in the notice of such meeting, but the
business proposed by the board of directors may be           limited partners may not engage in any activity which
considered at special meetings of stockholders.              would be deemed taking part in the management or
                                                             control of the partnership's business.
----------------------------------------------------------------------------------------------------------------------
Most amendments to Pioneer Parent's certificate of           Amendments to the partnership agreement of each
incorporation require the approval of the stockholders who   partnership generally require the approval by limited
own a majority of the outstanding shares of Pioneer Parent   partners holding a majority of outstanding limited
common stock.  A number of fundamental amendments,           partnership interests in the partnership.  An amendment
however, require approval by a greater percentage of         that has any of the following effects requires the
stockholders.  For example, any amendment to the following   unanimous approval of Pioneer USA and the limited
provisions requires the approval of two-thirds of the        partners: (1) increases the liability or duties of any
stockholders: (1) election of directors, (2) authority of    of the partners, (2) changes the contributions required
the board of directors, (3) stockholder meetings and (4)     of the partners, (3) provides for any reallocation of
limitation on the liability of directors.  Any amendment     profits, losses or deductions to the detriment of a
to the provision that prohibits action by the written        partner, (4) establishes any new priority in one or
consent of the stockholders in lieu of a meeting requires    more partners as to the return of capital contributions
the approval of 80% of the stockholders.  In addition, the   or as to profits, losses, deductions or distribution to
following actions require the approval of 80% of the         the detriment of a partner, or (5) causes the
stockholders and the approval of two-thirds of the           partnership to be taxed as a corporation.  Pioneer USA
disinterested stockholders:  (1) any merger, consolidation   may, in its sole discretion, adopt any of the following
or share exchange involving any person, other than Pioneer   amendments: (1) change the name of the partnership, (2)
Parent or a subsidiary of Pioneer Parent, who beneficially   change the location of the principal place of business
owns 10% or more of the outstanding voting securities of     of the partnership, (3) admit a new or substitute
Pioneer Parent, which person we call a related party, (2)    limited partner, (4) modify its general partnership
some sales, leases, exchanges or similar transactions with   interest as a result of a transfer of a portion of such
related parties, (3) some issuances of securities to         interest, (5) correct a typographical error, or (6) any
related parties, (4) adoption of any plan or proposal for    other similar change where the Pioneer USA determines
liquidation of Pioneer Parent initiated by related           that the amendment will not adversely affect the
parties, or (5) any series or combination of any of the      limited partners and Pioneer USA believes the amendment
actions described in clauses (1) through (4).                is necessary or advisable to qualify the partnership
                                                             under the laws of a state in which it engages or
                                                             proposes to engage in business or to keep the
                                                             partnership from being treated as a corporation for tax
                                                             purposes.
----------------------------------------------------------------------------------------------------------------------





                                      -76-
   87




----------------------------------------------------------------------------------------------------------------------
                          SHARES                                              PARTNERSHIP INTERESTS
----------------------------------------------------------------------------------------------------------------------
                                                          
                                              ANTI-TAKEOVER PROVISIONS
----------------------------------------------------------------------------------------------------------------------
The certificate of incorporation and bylaws of Pioneer       There are no anti-takeover provisions in the
Parent and the Delaware General Corporation Law include a    partnership agreement for any of the partnerships or
number of provisions which may have the effect of            under Delaware or Texas, as the case may be,
encouraging persons considering unsolicited tender offers    partnership law.
or other unilateral takeover proposals to negotiate with
Pioneer Parent's board of directors rather than pursue
non-negotiated takeover attempts.  These provisions
include (1) a classified board of directors, (2) advance
notice requirements for shareholder proposals and director
nominations, (3) restrictions on certain business
combinations and (4) prohibition against actions approved
by written consent without the approval of a specified
percentage of the shareholders.
----------------------------------------------------------------------------------------------------------------------
                                               CONTINUITY OF EXISTENCE
----------------------------------------------------------------------------------------------------------------------
Pioneer Parent has a perpetual existence.                    Except for the following partnerships, each partnership
                                                             has a finite life of 50 years from the year of its
                                                             formation.  The following partnerships continue until
                                                             terminated by mutual agreement of the partners of the
                                                             partnership:

                                                                  Parker & Parsley 81-I, Ltd.
                                                                  Parker & Parsley 81-II, Ltd.
                                                                  Parker & Parsley 82-I, Ltd.
                                                                  Parker & Parsley 82-II, Ltd.
                                                                  Parker & Parsley 82-III, Ltd.
                                                                  Parker & Parsley 83-A, Ltd.
                                                                  Parker & Parsley 83-B, Ltd.
                                                                  Parker & Parsley 84-A, Ltd.
----------------------------------------------------------------------------------------------------------------------
                                                  LIMITED LIABILITY
----------------------------------------------------------------------------------------------------------------------
A stockholder's liability will generally be limited to       Assuming the limited partners of a partnership do not
such stockholder's contribution to Pioneer Parent's          take part in the management or control of the business
capital. Under Delaware law, Pioneer Parent's stockholders   of such partnership, a limited partner's liability is
will not be liable for Pioneer Parent's debts or             generally limited to the limited partner's contribution
obligations.  The shares of Pioneer Parent common stock      to the capital of the partnership and such limited
offered by Pioneer Parent under this document, upon          partner's share of assets and undistributed profits of
issuance, will be fully paid and nonassessable.              the partnership.  A limited partner will receive a
                                                             return of the limited partner's capital contribution to
                                                             the partnership to the extent that a distribution to
                                                             the limited partner reduces the limited partner's share
                                                             of the fair value of the partnership's net assets below
                                                             the value of the limited partner's unreturned capital
                                                             contributions.  A substituted limited partner is
                                                             subject to the liabilities and obligations of the
                                                             substituted limited partner's assignor, except those
                                                             liabilities of which the substituted limited partner
                                                             was unaware at the time he became a substituted limited
                                                             partner and which could not be ascertained from the
                                                             partnership agreement of the partnership.
----------------------------------------------------------------------------------------------------------------------




                                      -77-
   88





----------------------------------------------------------------------------------------------------------------------
                          SHARES                                              PARTNERSHIP INTERESTS
----------------------------------------------------------------------------------------------------------------------
                                                          
                                          BUSINESS ACTIVITIES AND FINANCING
----------------------------------------------------------------------------------------------------------------------
Pioneer Parent's mission is to provide its stockholders      The business operations of each partnership have
with superior investment returns through strategies that     consisted of the development and production of oil and
maximize Pioneer Parent's long-term profitability and net    gas reserves.  Each partnership has expended its
asset values.  The strategies employed to achieve this       initial partnership capital, and additional properties
mission are anchored by Pioneer Parent's long-lived          cannot be acquired.  Operations can be financed only
Spraberry oil and gas field and Hugoton and West Panhandle   through permitted borrowings, reinvestment of earnings
gas fields' reserves and production.  Underlying these       not distributed, permitted assessments, or permitted
fields are approximately 67% of Pioneer Parent's proved      sales of assets.  Each partnership generally is
oil and gas reserves which have a remaining productive       required to distribute to its partners all or
life in excess of 40 years.  The stable base of oil and      substantially all its net cash flow from operations,
gas production from these fields generates operating cash    after provision for any reserves deemed appropriate by
flows that allow Pioneer Parent the financial flexibility    Pioneer USA.
to selectively reinvest capital:


o    to develop and increase production from existing
     properties through low-risk development drilling
     activities;
o    to leverage cost containment opportunities to achieve
     operating and technical efficiencies; and
o    to pursue strategic acquisitions in Pioneer Parent's
     core areas that will complement Pioneer Parent's
     existing asset base and provide additional growth
     opportunities.

Pioneer Parent also has the financial flexibility to use
portions of its operating cash flows:

o    to selectively expand into new geographic areas that
     feature producing properties and provide exploration
     or exploitation opportunities;
o    to invest in the personnel and technology necessary
     to increase Pioneer Parent's exploration
     opportunities; and
o    to enhance liquidity.

This flexibility allows Pioneer Parent to take advantage
of future exploration, development and acquisition
opportunities.
Pioneer Parent may engage in any phase of the oil and gas
business and any other lawful business.  Pioneer Parent
may finance its operations and the acquisition of
additional properties through, among other things, the
issuance of additional shares of Pioneer Parent common
stock, borrowings, and the reinvestment of earnings not
distributed to stockholders.
----------------------------------------------------------------------------------------------------------------------
                                                 FINANCIAL REPORTING
----------------------------------------------------------------------------------------------------------------------
Pioneer Parent is subject to the reporting requirements of   For a list of the partnerships that are subject to the
the Securities Exchange Act of 1934.                         reporting requirements of the Securities Exchange Act
                                                             of 1934, see "Where You Can Find More Information" on
                                                             the inside front cover page of this document. In
                                                             addition, the partnership agreement of each partnership
                                                             requires that some reports be delivered to the limited
                                                             partners.
----------------------------------------------------------------------------------------------------------------------



                                      -78-
   89





----------------------------------------------------------------------------------------------------------------------
                          SHARES                                              PARTNERSHIP INTERESTS
----------------------------------------------------------------------------------------------------------------------
                                                          
                                                   TAX INFORMATION
----------------------------------------------------------------------------------------------------------------------
"Double taxation" at the corporate and stockholder levels    None of the partnerships is a taxable entity for
typically results when a corporation such as Pioneer         federal income tax purposes.  The partners of each
Parent earns income and distributes that income to its       partnership are required to take into account their pro
stockholders in the form of dividends.  Stockholders will    rata share of the partnership's income, gains, losses,
only recognize income on amounts actually distributed by     and deductions, regardless of whether they receive any
Pioneer Parent.  Distributions made by Pioneer Parent out    cash distributions from the partnership.  Some partners
of current or accumulated earnings and profits are taxed     may be entitled to percentage depletion.  A partner
as dividend income.  Distributions in excess of current or   will be required to recapture some deductions and
accumulated earnings and profits are treated as a            credits upon the sale of all or a portion of his
non-taxable return of basis to the extent of stockholders'   partnership interests.
adjusted basis in their shares, with the excess taxed as
capital gain.
Dividends, if any, received by stockholders from Pioneer     A partner's share of a partnership's income and loss
Parent generally will constitute portfolio income, and       will be subject to the "passive activity" limitations.
cannot be offset with losses from "passive activities."      Under the passive activity rules, losses of a partner
Losses and credits generated within Pioneer Parent do not    arising from his ownership of partnership interests may
pass through to the stockholders.  After the end of          be used to offset passive income from another passive
Pioneer Parent's taxable year, stockholders will receive     investment and income of a partner arising from his
Form 1099-DIV to report their dividend income.               ownership of partnership interests may only be offset
                                                             with passive losses from another passive investment.
                                                             For a discussion of the tax consequences associated
                                                             with the merger of each partnership, see "The Merger of
                                                             Each Partnership-- Material U.S. Federal Income Tax
                                                             Consequences."
----------------------------------------------------------------------------------------------------------------------
                       DIVIDEND OR DISTRIBUTION POLICY AND PARTICIPATION IN PROFITS AND LOSSES
----------------------------------------------------------------------------------------------------------------------
The shares of Pioneer Parent common stock constitute         For a description of the distribution policies of each
equity interests in Pioneer Parent.  Each stockholder will   partnership, see "Risk Factors-- Risks Associated with
be entitled to his pro rata share of the dividends made      an Investment in Pioneer Parent-- Pioneer Parent Might
with respect to the Pioneer Parent common stock.  The        Not Declare Dividends." The average quarterly cash
dividends payable to the stockholders are not fixed in       distributions by each partnership for 1999, 2000 and
amount and are only paid if, as and when declared by         the year-to-date in 2001 are set forth in Table 7 of
Pioneer Parent's board of directors.  Dividends payable      Appendix A. For a description of the provisions of the
with respect to the shares of Pioneer Parent common stock    partnership agreement of each partnership governing the
depend upon the performance of Pioneer Parent.               allocation of costs and revenues among the
                                                             partnership's partners, see Table 9 of Appendix A.
----------------------------------------------------------------------------------------------------------------------



                                  LEGAL MATTERS


     Vinson & Elkins L.L.P., counsel to Pioneer Parent, will pass upon the
validity of the Pioneer Parent common stock to be issued upon the merger of each
partnership and material federal income tax matters related to the merger of
each partnership. The limited partners' special legal counsel,         , Dallas,
Texas, will deliver the legal opinion referred to in "The Merger of Each
Partnership -- Legal Opinion for Limited Partners" on page 47 of this document.
That special counsel may rely as to matters of law of jurisdictions other than
the United States and the State of Texas on the opinion of counsel in such other
jurisdictions.


           INDEPENDENT AUDITORS AND INDEPENDENT PETROLEUM CONSULTANTS


     The consolidated financial statements of Pioneer Parent appearing in its
Annual Report (Form 10-K) for the year ended December 31, 2000, have been
audited by Ernst & Young LLP, independent auditors, as set forth in their
report, which is incorporated by reference into this document. Such consolidated
financial statements are incorporated by reference in reliance upon such report
given on the authority of such firm as experts in accounting and auditing.


     The financial statements of each partnership listed on pages 4 and 5 of
this document at December 31, 2000 and 1999 and for each of the three years in
the period ended December 31, 2000 have been audited by Ernst & Young

                                      -79-
   90


LLP, independent auditors, as set forth in their reports included in the
supplemental information to this document for each partnership. Such financial
statements are included in the supplemental information of each partnership in
reliance upon such reports given on the authority of such firm as experts in
accounting and auditing.


     Williamson Petroleum Consultants, Inc., independent petroleum consultants,
estimated each partnership's reserves as of December 31, 2000, and reviewed
Pioneer Parent's and Pioneer USA's estimates of each partnership's reserves as
of March 31, 2001 and the present value of the estimated future net revenues
from those estimated reserves included in the summary reserve reports included
in this document and such summary reserve reports and estimates and the review
as of March 31, 2001, are included in this document in reliance upon their
reports given upon their authority as experts on the matters covered by the
summary reserve report and review.





                                      -80-
   91


                         COMMONLY USED OIL AND GAS TERMS

     The definitions set forth below shall apply to the indicated terms as used
in this document. All volumes of natural gas referred to herein are stated at
the legal pressure base of the state or area where the reserves exist and at 60
degrees Fahrenheit and in most instances are rounded to the nearest major
multiple.

     "Bbl" means a standard barrel of 42 U.S. gallons and represents the basic
unit for measuring the production of crude oil, natural gas liquids and
condensate.

     "Bcf" means one billion cubic feet under prescribed conditions of pressure
and temperature and represents the basic unit for measuring the production of
natural gas.

     "BOE" means a barrel-of-oil-equivalent and is a customary convention used
in the United States to express oil and gas volumes on a comparable basis. It is
determined on the basis of the estimated relative energy content of natural gas
to oil, being approximately six Mcf of natural gas per Bbl of oil.

     "BTU" means British thermal unit.


     "development drilling" means drilling within the proved area of an oil or
gas reservoir to the depth of a stratigraphic horizon known to be productive.



     "exploration activity" means drilling activity to find and produce oil or
natural gas in an area that is not known to be an oil or natural gas reservoir,
or drilling activity to extend a known reservoir.


     "Mbbl" means one thousand Bbls.

     "MBOE" means one thousand BOEs.

     "Mcf" means one thousand cubic feet under prescribed conditions of pressure
and temperature and represents the basic unit for measuring the production of
natural gas.

     "MMBbl" means one million Bbls.

     "MMcf" means one million cubic feet under prescribed conditions of pressure
and temperature and represents the basic unit for measuring the production of
natural gas.

     "NGLs" means natural gas liquids.

     "proved reserves" means the estimated quantities of crude oil, natural gas,
and natural gas liquids which geological and engineering data demonstrate with
reasonable certainty to be recoverable in future years from known reservoirs
under existing economic and operating conditions, i.e., prices and costs as of
the date the estimate is made. Prices include consideration of changes in
existing prices provided only by contractual arrangements, but not on
escalations based upon future conditions.

               (i) Reservoirs are considered proved if economic producibility is
          supported by either actual production or conclusive formation test.
          The area of a reservoir considered proved includes (A) that portion
          delineated by drilling and defined by gas-oil and/or oil-water
          contacts, if any; and (B) the immediately adjoining portions not yet
          drilled, but which can be reasonably judged as economically productive
          on the basis of available geological and engineering data. In the
          absence of information on fluid contacts, the lowest known structural
          occurrence of hydrocarbons controls the power proved limit of the
          reservoir.

               (ii)Reserves which can be produced economically through
          application of improved recovery techniques (such as fluid injection)
          are included in the "proved" classification when successful testing by
          a pilot project, or the operation of an installed program in the
          reservoir, provides support for the engineering analysis on which the
          project or program was based.

               (iii) Estimates of proved reserves do not include the following:
          (A) oil that may become available from known reservoirs but is
          classified separately as "indicated additional reserves"; (B) crude
          oil, natural gas, and natural gas liquids, the recovery of which is
          subject to reasonable doubt because of uncertainty as to geology,
          reservoir characteristics, or economic factors; (C) crude oil, natural
          gas, and natural gas liquids, that may occur in undrilled prospects;
          and (D) crude oil, natural gas, and natural gas liquids, that may be
          recovered from oil shales, coal, gilsonite and other such sources.


                                      -81-
   92
                        PIONEER NATURAL RESOURCES COMPANY

                UNAUDITED PRO FORMA COMBINED FINANCIAL STATEMENTS

INTRODUCTORY STATEMENTS


     The unaudited pro forma combined financial statements of Pioneer Parent
have been prepared to give effect to Pioneer Parent's offer to acquire 46
limited partnerships (collectively, the "Combined Partnerships") that Pioneer
USA serves as the sole or managing general partner.

     The unaudited pro forma combined balance sheet of Pioneer Parent as of
March 31, 2001 has been prepared to give effect to the acquisition of the
Combined Partnerships as if it had occurred on March 31, 2001.

     The unaudited pro forma combined statements of operations of Pioneer Parent
for the three months ended March 31, 2001 and for the year ended December 31,
2000 have been prepared to give effect to the acquisition of the Combined
Partnerships as if it had occurred on January 1, 2000.

     The unaudited pro forma combined financial statements included herein are
not necessarily indicative of the results that might have occurred had the
transaction taken place on the dates that are assumed for the pro forma
presentations and are not intended to be a projection of future results. Future
results may vary significantly from the results reflected in the accompanying
unaudited pro forma combined financial statements because of normal production
declines, changes in product prices, future acquisitions and divestitures,
future development and exploration activities, and other factors.

     The following unaudited pro forma combined financial statements should be
read in conjunction with the Consolidated Financial Statements (and the related
notes) of Pioneer Parent included in the Annual Report on Form 10-K for the year
ended December 31, 2000, the Quarterly Report on Form 10-Q for the three months
ended March 31, 2001 and the historical financial statements of each partnership
in which you own an interest contained in the supplement to this document for
the partnership.





                                      P-1
   93



                        PIONEER NATURAL RESOURCES COMPANY


                   UNAUDITED PRO FORMA COMBINED BALANCE SHEET
                              AS OF MARCH 31, 2001
                        (IN THOUSANDS, EXCEPT SHARE DATA)





                                                        ASSETS

                                                      PIONEER         COMBINED           PRO FORMA         PRO FORMA
                                                       PARENT       PARTNERSHIPS        ADJUSTMENTS      PIONEER PARENT
                                                    ------------    ------------       ------------      --------------
                                                                                             
Current assets:
  Cash and cash equivalents .....................   $     18,305    $      5,153       $     (5,153)(c)   $     18,305
  Accounts receivable:
    Trade, net ..................................        102,437           7,362                               109,799
    Affiliates ..................................          1,479            --                 (929)(b)            550
  Inventories ...................................         12,965            --                                  12,965
  Deferred income taxes .........................          4,800            --                                   4,800
  Other current assets ..........................         18,242            --                                  18,242
                                                    ------------    ------------                          ------------
      Total current assets ......................        158,228          12,515                               164,661
                                                    ------------    ------------                          ------------

Property, plant and equipment, at cost:
  Oil and gas properties, using the successful
    efforts method of accounting:
        Proved properties........................      3,288,356         356,847           (255,941)(a)      3,389,262
        Unproved properties......................        216,322            --                                 216,322
  Accumulated depletion, depreciation and
    amortization ................................       (947,580)       (310,495)           310,495 (a)       (947,580)
                                                    ------------    ------------                          ------------
                                                       2,557,098          46,352                             2,658,004
                                                    ------------    ------------                          ------------

Deferred income taxes ...........................         85,200            --                                  85,200
Other property and equipment, net ...............         22,497            --                                  22,497
Other assets, net ...............................         99,185            --                                  99,185
                                                    ------------    ------------                          ------------
                                                    $  2,922,208    $     58,867                          $  3,029,547
                                                    ============    ============                          ============

                                         LIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities:
  Accounts payable:
    Trade .......................................   $    110,795    $         24       $      1,911 (c)   $    112,730
    Affiliates ..................................          1,802             929               (929)(b)          1,802
  Interest payable ..............................         38,863            --                                  38,863
  Other current liabilities:
    Derivative obligations ......................        109,118            --                                 109,118
    Other .......................................         50,713            --                                  50,713
                                                    ------------    ------------                          ------------
      Total current liabilities .................        311,291             953                               313,226
                                                    ------------    ------------                          ------------

Long-term debt, less current maturities .........      1,550,230            --                               1,550,230
Other noncurrent liabilities ....................        194,615            --                                 194,615
Deferred income taxes ...........................         25,100            --                                  25,100
Partners' capital ...............................           --            57,914            (57,914)(a)(c)        --
Stockholders' equity:
  Common stock ..................................          1,015            --                   59 (a)          1,074
  Additional paid-in capital ....................      2,354,778            --              105,345 (a)      2,460,123
  Treasury stock ................................        (44,752)           --                                 (44,752)
  Accumulated deficit ...........................     (1,354,784)           --                              (1,354,784)
  Accumulated other comprehensive income:
    Deferred hedge gains and losses .............       (110,507)           --                                (110,507)
    Unrealized gain on available for sale
      securities ................................          1,054            --                                   1,054
    Cumulative translation adjustment ...........         (5,832)           --                                  (5,832)
                                                    ------------    ------------                          ------------
      Total stockholders' equity and
         partners' capital ......................        840,972          57,914                               946,376
                                                    ------------    ------------                          ------------
Commitments and contingencies ...................   $  2,922,208    $     58,867                          $  3,029,547
                                                    ============    ============                          ============




         The accompanying notes are an integral part of these unaudited
                    pro forma combined financial statements.




                                      P-2
   94



                        PIONEER NATURAL RESOURCES COMPANY


              UNAUDITED PRO FORMA COMBINED STATEMENT OF OPERATIONS
                        THREE MONTHS ENDED MARCH 31, 2001
                      (IN THOUSANDS, EXCEPT PER SHARE DATA)





                                                                                                                 PRO FORMA
                                                           PIONEER         COMBINED            PRO FORMA          PIONEER
                                                            PARENT       PARTNERSHIPS         ADJUSTMENTS         PARENT
                                                         ------------    ------------       ---------------    ------------
                                                                                                   
Revenues:
  Oil and gas ........................................   $    257,986    $     13,727       $       (959)(d)   $    270,754
  Interest and other .................................          5,167             101                 (7)(d)          5,261
  Gain on disposition of assets, net .................          7,293              75               --                7,368
                                                         ------------    ------------                          ------------
                                                              270,446          13,903                               283,383
                                                         ------------    ------------                          ------------
Cost and expenses:
  Oil and gas production .............................         55,802           5,228                (83)(d)
                                                                                                  (1,414)(e)         59,533
  Depletion, depreciation and
    amortization .....................................         52,161             892                701 (f)         53,754
  Exploration and abandonments .......................         22,883              41               --               22,924
  General and administrative .........................         10,448             445                (25)(d)
                                                                                                   1,414 (e)         12,282
  Interest ...........................................         35,616            --                                  35,616
  Other ..............................................         25,217            --                                  25,217
                                                         ------------    ------------                          ------------
                                                              202,127           6,606                               209,326
                                                         ------------    ------------                          ------------

Income from continuing operations before
   income taxes ......................................         68,319           7,297                                74,057
Income tax benefit ...................................           (400)           --                 --   (h)           (400)
                                                         ------------    ------------                          ------------
Income from continuing operations ....................   $     67,919    $      7,297                          $     73,657
                                                         ============    ============                          ============

Income from continuing operations per common share:
    Basic ............................................   $        .69                                          $        .71
                                                         ============                                          ============
    Diluted ..........................................   $        .68                                          $        .70
                                                         ============                                          ============
Weighted average shares outstanding:
    Basic ............................................         98,379                              5,856 (i)        104,235
                                                         ============                                          ============
    Diluted ..........................................         99,708                              5,856 (i)        105,564
                                                         ============                                          ============




                  See accompanying notes to unaudited pro forma
                         combined financial statements.



                                      P-3
   95


                        PIONEER NATURAL RESOURCES COMPANY



              UNAUDITED PRO FORMA COMBINED STATEMENT OF OPERATIONS
                          YEAR ENDED DECEMBER 31, 2000
                      (IN THOUSANDS, EXCEPT PER SHARE DATA)





                                                     PIONEER            COMBINED            PRO FORMA           PRO FORMA
                                                      PARENT          PARTNERSHIPS         ADJUSTMENTS        PIONEER PARENT
                                                   -------------    -----------------    -----------------    ---------------
                                                                                                     
Revenues:
  Oil and gas...............................       $    852,738       $       52,013      $   (3,369)(d)         $   901,382
  Interest and other........................             25,775                  484             (28)(d)              26,231
  Gain on disposition of assets, net........             34,184                  247              (6)(d)              34,425
                                                   ------------       --------------                             -----------
                                                        912,697               52,744                                 962,038
                                                   ------------       --------------                             -----------
Cost and expenses:
  Oil and gas production....................            189,265               19,958          (1,392)(d)
                                                                                              (5,655)(e)             202,176
  Depletion, depreciation and
    amortization............................            214,938                3,236           3,768 (f)             221,942
  Impairment of oil and gas properties......                 --                  663            (663)(g)                --
  Exploration and abandonments..............             87,550                   72              (3)(d)              87,619
  General and administrative................             33,262                1,599            (110)(d)
                                                                                               5,655 (e)              40,406
  Interest..................................            161,952                   --                                 161,952
  Other.....................................             67,231                   --                                  67,231
                                                   ------------       --------------                             -----------
                                                        754,198               25,528                                 781,326
                                                   ------------       --------------                             -----------

Income from continuing operations before
   income taxes.............................            158,499               27,216                                 180,712
Income tax benefit..........................              6,000                   --              -- (h)               6,000
                                                   ------------       --------------                             -----------
Income from continuing operations...........       $    164,499       $       27,216                             $   186,712
                                                   ============       ==============                             ===========

Income from continuing operations per
   common share:
    Basic...................................       $       1.65                                                  $      1.77
                                                   ============                                                  ===========
    Diluted.................................       $       1.65                                                  $      1.77
                                                   ============                                                  ===========
Weighted average shares outstanding:
    Basic...................................             99,378                                5,856(i)              105,234
                                                   ============                                                  ===========
    Diluted.................................             99,762                                5,856(i)              105,618
                                                   ============                                                  ===========




                  See accompanying notes to unaudited pro forma
                         combined financial statements.



                                      P-4
   96
                        PIONEER NATURAL RESOURCES COMPANY


                      NOTES TO UNAUDITED PRO FORMA COMBINED
                              FINANCIAL STATEMENTS
                      MARCH 31, 2001 AND DECEMBER 31, 2000



NOTE 1.  BASIS OF PRESENTATION


     The unaudited pro forma combined financial information of Pioneer Natural
Resources Company ("Pioneer Parent") has been prepared to give effect to Pioneer
Parent's offer to acquire 46 limited partnerships (collectively, the "Combined
Partnerships") that Pioneer USA serves as the sole or managing general partner.
The unaudited pro forma combined balance sheet as of March 31, 2001 has been
prepared to give effect to the acquisition of the Combined Partnerships as if it
had occurred on March 31, 2001. The unaudited pro forma combined statements of
operations for the three months ended March 31, 2001 and for the year ended
December 31, 2000 are presented as if the acquisition of the Combined
Partnerships occurred on January 1, 2000.


     Following is a description of the individual columns included in these
unaudited pro forma combined financial statements:


     Pioneer Parent - Represents the consolidated balance sheet of Pioneer
  Parent as of March 31, 2001, and the consolidated statements of operations of
  Pioneer Parent for the three months ended March 31, 2001 and the year ended
  December 31, 2000.



     Combined Partnerships - Represents the combined balance sheets of the 46
  limited partnerships as of March 31, 2001 and the combined statements of
  operations of such limited partnerships for the three months ended March 31,
  2001 and the year ended December 31, 2000.


NOTE 2.  PRO FORMA ADJUSTMENTS

     Following are descriptions of the pro forma adjustments used in the
preparation of the accompanying unaudited pro forma combined financial
statements:


  (a)  To record the acquisition of the Combined Partnerships, using the
       purchase method of accounting, for $105.4 million in Pioneer common
       stock, representing 5,855,813 shares assuming an $18.00 average stock
       price. The allocation of the purchase price to the acquired assets and
       liabilities is preliminary and, therefore, subject to change.



       The purchase price allocation as of March 31, 2001 reflects the fair
       value of the Combined Partnerships' assets and liabilities as of that
       date. A final purchase price allocation will be done at closing based
       upon the fair value of the Combined Partnerships' assets and liabilities
       at that time. The date three business days prior to the special meeting
       of limited partners of each partnership to be held on , 2001 will be the
       measurement date for determining the final number of shares of Pioneer
       Parent common stock to be issued (the "Measurement Date"). Pioneer Parent
       will value the shares to be issued using the average closing price of
       Pioneer Parent common stock for the five-day period comprised of the two
       days prior to the Measurement Date, the Measurement Date and the two
       business days subsequent to the Measurement Date. The final allocation is
       not anticipated to change materially other than for cash flow generated
       from the Combined Partnerships' property interests between March 31, 2001
       and closing, which will be reflected as a reduction to oil and gas
       properties and an increase to working capital in the final purchase price
       allocation.



  (b)  To eliminate affiliate receivables and affiliate payables between Pioneer
       Parent and the Combined Partnerships.



  (c)  To adjust pro forma cash, accounts payable and partners' capital for the
       $7.1 million cash distribution that will be disbursed to existing
       partners other than Pioneer USA during July 2001.



  (d)  To eliminate Pioneer Parent's proportionate share of the Combined
       Partnerships that is already reflected in Pioneer Parent's consolidated
       statements of operations for the three months ended March 31, 2001 and
       for the year ended December 31, 2000.



                                      P-5
   97
                        PIONEER NATURAL RESOURCES COMPANY


                      NOTES TO UNAUDITED PRO FORMA COMBINED
                              FINANCIAL STATEMENTS
                      MARCH 31, 2001 AND DECEMBER 31, 2000




  (e)  To eliminate the Combined Partnership's share of operating overhead
       charged by Pioneer Parent that was recorded by the Combined Partnerships
       as an increase in lease operating expenses and by Pioneer Parent as a
       reduction to general and administrative expense.



  (f)  To adjust depreciation, depletion and amortization expense for the basis
       allocated to the oil and gas properties acquired and accounted for using
       the successful efforts method of accounting.



  (g)  To eliminate the Combined Partnerships impairment of oil and gas
       properties that would not occur on a pro forma basis with Pioneer Parent
       due to the basis in oil and gas properties reflecting the value assigned
       using the purchase method of accounting.



  (h)  Pioneer Parent has unused net operating loss carryovers in the United
       States that could be used to offset any incremental earnings of the
       Combined Partnerships. Accordingly, no pro forma adjustment was recorded
       for additional income tax expense. See Note 3. below.



  (i)  To adjust the weighted average basic and diluted common shares
       outstanding for the issuance of 5,855,813 shares of Pioneer Parent common
       stock to acquire the Combined Partnerships.



       The pro forma numerator for basic and diluted earnings per share
       calculations equals "income from continuing operations" per the Unaudited
       Pro Forma Combined Statement of Operations (see page P-3). Following is a
       reconciliation of the pro forma weighted average basic and diluted shares
       outstanding (in thousands):





                                                             March 31, 2001      December 31, 2000
                                                             --------------      -----------------
                                                                           
        Pioneer Parent weighted average basic common
        shares outstanding...............................         98,379                 99,378

        Shares offered attributable to the additional
        nonmanaging general partners' interests..........             11                     11

        Shares offered attributable to the additional
        limited partners' interests......................          5,845                  5,845
                                                               ---------              ---------
        Pro forma Pioneer Parent weighted average basic
        shares outstanding...............................        104,235                105,234

        Effect of dilutive common stock options..........          1,329                    384
                                                               ---------              ---------
        Pro forma Pioneer Parent weighted average diluted
        shares outstanding...............................        105,564                105,618
                                                               =========              =========



NOTE 3.  INCOME TAXES


     Pioneer Parent will account for income taxes in accordance with the
provisions of Statement of Financial Accounting Standards No. 109, "Accounting
for Income Taxes". In accordance therewith, Pioneer Parent will prepare separate
tax calculations for each tax jurisdiction in which Pioneer Parent will be
subject to income taxes. Pioneer Parent has unused net operating loss carryovers
and alternative minimum tax net operating loss carryovers that would be utilized
to reduce incremental United States income taxes that would otherwise be
incurred as a result of pro forma pre-tax earnings of the Combined Partnerships.
Accordingly, Pioneer Parent has not recognized incremental income tax expense in
the accompanying unaudited pro forma combined statements of operations for the
three months ended March 31, 2001 and the year ended December 31, 2000.


NOTE 4.  OIL AND GAS RESERVE DATA


     The following unaudited pro forma supplemental information regarding the
oil and gas activities of Pioneer Parent is presented pursuant to the disclosure
requirements promulgated by the Securities and Exchange Commission and Statement
of Financial Accounting Standards No. 69, "Disclosures About Oil and Gas
Producing Activities". The pro forma combined reserve information is presented
as if the acquisition of the Combined Partnerships had occurred on January 1,
2000. Information for oil and NGL's are presented in barrels (Bbls) and for gas
in thousands of cubic feet (Mcf).




                                      P-6
   98
                        PIONEER NATURAL RESOURCES COMPANY


                      NOTES TO UNAUDITED PRO FORMA COMBINED
                              FINANCIAL STATEMENTS
                      MARCH 31, 2001 AND DECEMBER 31, 2000




     Pioneer Parent emphasizes that reserve estimates are inherently imprecise
and subject to revision and that estimates of new discoveries are more imprecise
than those of producing oil and gas properties. Accordingly, the estimates are
expected to change as future information becomes available and such changes
could be significant.



     For additional information regarding the oil and gas activities of Pioneer
Parent and the Combined Partnerships, from which the following unaudited pro
forma supplemental information was derived, please see: (a) Pioneer Parent's
Annual Report on Form 10-K for the year ended December 31, 2000 for information
regarding Pioneer Parent's stand-alone oil and gas activities, (b) Table 11 of
Appendix A and (c) the review by Williamson Petroleum Consultants, Inc. of the
Summary Reserve Report for the Combined Partnerships included in Appendix B for
the volumes and values attributable to the Combined Partnerships.





                                      P-7
   99
                        PIONEER NATURAL RESOURCES COMPANY


                      NOTES TO UNAUDITED PRO FORMA COMBINED
                              FINANCIAL STATEMENTS
                      MARCH 31, 2001 AND DECEMBER 31, 2000



QUANTITIES OF OIL AND GAS RESERVES

     Set forth below is a pro forma summary of the changes in the net quantities
of oil, NGL and natural gas reserves for the year ended December 31, 2000.




                                        OIL
                                        & NGLs         GAS
                                       (MBbls)        (MMcf)         MBOE
                                      ----------    ----------    ----------
                                                         
TOTAL PROVED RESERVES:

UNITED STATES
Balance, January 1 ................      290,683     1,365,530       518,271
Revisions of previous estimates ...       18,704        54,518        27,790
Purchases of minerals-in-place ....        1,237        28,071         5,916
New discoveries and extensions ....        4,819        66,486        15,900
Production ........................      (18,571)      (86,206)      (32,939)
Sales of minerals-in-place ........         (743)      (35,054)       (6,586)
                                      ----------    ----------    ----------
Balance, December 31 ..............      296,129     1,393,345       528,352


ARGENTINA
Balance, January 1 ................       29,797       415,620        99,067
Revisions of previous estimates ...        1,411       (15,558)       (1,182)
Purchases of minerals-in-place ....         --            --            --
New discoveries and extensions ....        8,066        43,914        15,385
Production ........................       (3,431)      (35,694)       (9,380)
Sales of minerals-in-place ........         --            --            --
                                      ----------    ----------    ----------
Balance, December 31 ..............       35,843       408,282       103,890

CANADA
Balance, January 1 ................        3,970       145,251        28,179
Revisions of previous estimates ...          429       (10,013)       (1,240)
Purchases of minerals-in-place ....          140         7,768         1,435
New discoveries and extensions ....          138         6,132         1,160
Production ........................         (611)      (16,219)       (3,315)
Sales of minerals-in-place ........         --            --            --
                                      ----------    ----------    ----------
Balance, December 31 ..............        4,066       132,919        26,219

SOUTH AFRICA
Balance, January 1 ................         --            --            --
New discoveries and extensions ....        5,552          --           5,552
                                      ----------    ----------    ----------
Balance, December 31 ..............        5,552          --           5,552

TOTAL
Balance, January 1 ................      324,450     1,926,401       645,517
Revisions of previous estimates ...       20,544        28,947        25,368
Purchases of minerals-in-place ....        1,377        35,839         7,351
New discoveries and extensions ....       18,575       116,532        37,997
Production ........................      (22,613)     (138,119)      (45,634)
Sales of minerals-in-place ........         (743)      (35,054)       (6,586)
                                      ----------    ----------    ----------
Balance, December 31 ..............      341,590     1,934,546       664,013
                                      ==========    ==========    ==========

PROVED DEVELOPED RESERVES:
  United States ...................      241,253     1,169,664       436,198
  Argentina .......................       22,931       358,124        82,618
  Canada ..........................        2,598        61,210        12,800
                                      ----------    ----------    ----------
    January 1 .....................      266,782     1,588,998       531,616
                                      ==========    ==========    ==========

  United States ...................      236,249     1,120,610       423,018
  Argentina .......................       22,679       345,281        80,226
  Canada ..........................        2,930        80,953        16,422
                                      ----------    ----------    ----------
    December 31 ...................      261,858     1,546,844       519,666
                                      ==========    ==========    ==========






                                      P-8
   100
                        PIONEER NATURAL RESOURCES COMPANY


                      NOTES TO UNAUDITED PRO FORMA COMBINED
                              FINANCIAL STATEMENTS
                      MARCH 31, 2001 AND DECEMBER 31, 2000



STANDARDIZED MEASURE OF DISCOUNTED FUTURE NET CASH FLOWS

     The pro forma standardized measure of discounted future net cash flow is
computed by applying year-end prices of oil and gas (with consideration of price
changes only to the extent provided by contractual arrangements) to the
estimated future production of oil and gas reserves less estimated future
expenditures (based on year-end costs) to be incurred in developing and
producing the proved reserves discounted using a rate of 10 percent per year to
reflect the estimated timing of the future cash flows. Future income taxes are
calculated by comparing undiscounted future cash flows to the tax basis of oil
and gas properties plus available carryforwards and credits and applying the
current tax rate to the difference.



                                                                DECEMBER 31, 2000
                                                                -----------------
                                                                 (IN THOUSANDS)
                                                              
UNITED STATES
Oil and gas producing activities:
  Future cash inflows ........................................   $ 19,615,577
  Future production costs ....................................     (5,290,990)
  Future development costs ...................................       (479,290)
  Future income tax expenses .................................     (3,945,569)
                                                                 ------------
                                                                    9,899,728
  10% annual discount factor .................................     (4,991,172)
                                                                 ------------
  Standardized measure of discounted future net cash flows ...   $  4,908,556
                                                                 ============

ARGENTINA
Oil and gas producing activities:
  Future cash inflows ........................................   $  1,183,652
  Future production costs ....................................       (215,853)
  Future development costs ...................................       (114,606)
  Future income tax expenses .................................        (81,705)
                                                                 ------------
                                                                      771,488
  10% annual discount factor .................................       (264,126)
                                                                 ------------
  Standardized measure of discounted future net cash flows ...   $    507,362
                                                                 ============

CANADA
Oil and gas producing activities:
  Future cash inflows ........................................   $  1,029,007
  Future production costs ....................................       (104,189)
  Future development costs ...................................        (35,443)
  Future income tax expenses .................................       (306,399)
                                                                 ------------
                                                                      582,976
  10% annual discount factor .................................       (168,441)
                                                                 ------------
  Standardized measure of discounted future net cash flows ...   $    414,535
                                                                 ============

SOUTH AFRICA
Oil and gas producing activities:
  Future cash inflows ........................................   $    126,134
  Future production costs ....................................        (65,232)
  Future development costs ...................................        (47,970)
  Future income tax expenses .................................           --
                                                                 ------------
                                                                       12,932
  10% annual discount factor .................................         (5,782)
                                                                 ------------
  Standardized measure of discounted future net cash flows ...   $      7,150
                                                                 ============

TOTAL
Oil and gas producing activities:
  Future cash inflows ........................................   $ 21,954,370
  Future production costs ....................................     (5,676,264)
  Future development costs ...................................       (677,309)
  Future income tax expenses .................................     (4,333,673)
                                                                 ------------
                                                                   11,267,124
  10% annual discount factor .................................     (5,429,521)
                                                                 ------------
  Standardized measure of discounted future net cash flows ...   $  5,837,603
                                                                 ============




                                      P-9
   101
                        PIONEER NATURAL RESOURCES COMPANY


                      NOTES TO UNAUDITED PRO FORMA COMBINED
                              FINANCIAL STATEMENTS
                      MARCH 31, 2001 AND DECEMBER 31, 2000



CHANGES RELATING TO THE PRO FORMA STANDARDIZED MEASURE OF DISCOUNTED FUTURE NET
CASH FLOWS

     The principal sources of the change in the pro forma combined standardized
measure of discounted future net cash flows for the year ended December 31, 2000
are as follows (in thousands):



                                                                             
                Oil and gas sales, net of production costs................      $    (699,206)
                Net changes in prices and production costs................          3,920,249
                Extension and discoveries.................................            525,361
                Development costs incurred during the period..............            101,350
                Sales of minerals-in-place................................            (72,624)
                Purchases of mineral-in-place.............................            187,097
                Revisions of estimated future development costs...........           (200,734)
                Revisions of previous quantity estimates..................            329,124
                Accretion of discount.....................................            313,281
                Changes in production rates, timing and other.............           (270,400)
                                                                                -------------
                Change in present value of future net revenues............          4,133,498
                Net change in present value of future income taxes........         (1,428,700)
                                                                                -------------
                                                                                    2,704,798
                Balance, beginning of year................................          3,132,805
                                                                                -------------
                Balance, end of year......................................      $   5,837,603
                                                                                =============








                                      P-10
   102
                                   APPENDIX A

                                       TO

                           PROXY STATEMENT/PROSPECTUS

                GENERAL INFORMATION RELATING TO EACH PARTNERSHIP


Table 1   Jurisdiction of Organization, Initial Subscription Price for Each
          Unit, Initial Investment by Limited Partners and Number of Limited
          Partners as of March 31, 2001


Table 2   Merger Value Attributable to Pioneer USA, Nonmanaging General
          Partners and Limited Partners



Table 3   Merger Value Attributable to Partnership Interests of Limited
          Partners Per $1,000 Investment



Table 4   Ownership Percentage and Merger Value Attributable to Nonmanaging
          General Partners Other Than Pioneer USA



Table 5   Ownership Percentage and Merger Value Attributable to Pioneer USA
          in Its Capacities as General Partner, Nonmanaging General Partner and
          Limited Partner


Table 6   Voting Percentage and Initial Investment Owned by Pioneer USA in
          Its Capacity as a Limited Partner as of March 31, 2001


Table 7   Historical Quarterly Partnership Distributions to the Limited
          Partners Per $1,000 Investment from Inception through July 31, 2001


Table 8   Annual Repurchase Prices and Aggregate Annual Repurchase Payments

Table 9   Participation in Costs and Revenues of Each Partnership

Table 10  Average Oil, Natural Gas Liquids and Gas Sales Prices and
          Production Costs for the Three Months Ended March 31, 2001 and 2000
          and the Years Ended December 31, 2000, 1999 and 1998

Table 11  Proved Reserves Attributable to Pioneer USA, Nonmanaging General
          Partners and Limited Partners as of December 31, 2000


Table 12  Partnership Estimated Reserves Attributable to Pioneer USA,
          Nonmanaging General Partners and Limited Partners as of March 31, 2001


Table 13  Oil, Natural Gas Liquids and Gas Production for the Three Months
          Ended March 31, 2001 and 2000 and the Years Ended December 31, 2000,
          1999 and 1998


Table 14  Productive Wells and Developed Acreage as of March 31, 2001


Table 15  Recent Trades of Partnership Interests Per $1,000 Investments for
          the Three Months Ended March 31, 2001 and the Years Ended December 31,
          2000 and 1999


Table 16  Reserve Value Attributable to Pioneer USA, Nonmanaging General
          Partners and Limited Partners as of March 31, 2001





                                      A-1
   103



                                     TABLE 1

     JURISDICTION OF ORGANIZATION, INITIAL SUBSCRIPTION PRICE FOR EACH UNIT,
      INITIAL INVESTMENT BY LIMITED PARTNERS AND NUMBER OF LIMITED PARTNERS
                              AS OF MARCH 31, 2001






                                                                                                 INITIAL
                                                                               INITIAL          INVESTMENT
                                                                             SUBSCRIPTION       BY LIMITED           NUMBER OF
                                                          JURISDICTION OF      PRICE FOR         PARTNERS             LIMITED
                                                            ORGANIZATION       EACH UNIT      (IN THOUSANDS)          PARTNERS
                                                          ---------------   --------------    ---------------       -----------
                                                                                                        
PARKER & PARSLEY 81-I, LTD.                                         Texas   $         5,000   $         7,410               135
PARKER & PARSLEY 81-II, LTD.                                        Texas             5,000             6,440               158
PARKER & PARSLEY 82-I, LTD.                                         Texas             2,000            11,805               606
PARKER & PARSLEY 82-II, LTD.                                        Texas             2,000            12,252               770
PARKER & PARSLEY 82-III, LTD.                                       Texas             2,000             6,882               418
PARKER & PARSLEY 83-A, LTD.                                         Texas             1,000            19,505             1,269
PARKER & PARSLEY 83-B, LTD.                                         Texas             1,000            23,370             1,374
PARKER & PARSLEY 84-A, LTD.                                         Texas             1,000            19,435             1,244
PARKER & PARSLEY 85-A, LTD.                                         Texas             1,000             9,613               796
PARKER & PARSLEY 85-B, LTD.                                         Texas             1,000             7,988               717
PARKER & PARSLEY PRIVATE INVESTMENT 85-A, LTD.                      Texas            40,000             5,000               107
PARKER & PARSLEY SELECTED 85 PRIVATE INVESTMENT, LTD.               Texas            40,000             4,690                79
PARKER & PARSLEY 86-A, LTD.                                         Texas             1,000            10,131               962
PARKER & PARSLEY 86-B, LTD.                                         Texas             1,000            17,208             1,390
PARKER & PARSLEY 86-C, LTD.                                         Texas             1,000            19,317             1,327
PARKER & PARSLEY PRIVATE INVESTMENT 86, LTD.                        Texas            40,000             4,920               103
PARKER & PARSLEY 87-A CONV., LTD.                                   Texas             1,000             3,856               214
PARKER & PARSLEY 87-A, LTD.                                         Texas             1,000            28,811             2,132
PARKER & PARSLEY 87-B CONV., LTD.                                   Texas             1,000             4,919               259
PARKER & PARSLEY 87-B, LTD.                                         Texas             1,000            20,089             1,464
PARKER & PARSLEY PRODUCING PROPERTIES 87-A, LTD.                    Texas               500            12,213             1,098
PARKER & PARSLEY PRODUCING PROPERTIES 87-B, LTD.                    Texas               500             6,096               549
PARKER & PARSLEY PRIVATE INVESTMENT 87, LTD.                        Texas            40,000            10,480               197
PARKER & PARSLEY 88-A CONV., L.P.                                Delaware             1,000             3,793               236
PARKER & PARSLEY 88-A, L.P.                                      Delaware             1,000            12,935               981
PARKER & PARSLEY 88-B CONV., L.P.                                Delaware             1,000             3,636               240
PARKER & PARSLEY 88-B, L.P.                                      Delaware             1,000             8,954               690
PARKER & PARSLEY 88-C CONV., L.P.                                Delaware             1,000             3,411               219
PARKER & PARSLEY 88-C, L.P.                                      Delaware             1,000             2,431               191
PARKER & PARSLEY PRODUCING PROPERTIES 88-A, L.P.                 Delaware               500             5,611               507
PARKER & PARSLEY PRIVATE INVESTMENT 88, L.P.                     Delaware            40,000             9,960               153
PARKER & PARSLEY 89-A CONV., L.P.                                Delaware             1,000             2,797               191
PARKER & PARSLEY 89-A, L.P.                                      Delaware             1,000             8,317               608
PARKER & PARSLEY 89-B CONV., L.P.                                Delaware             1,000             6,307               341
PARKER & PARSLEY 89-B, L.P.                                      Delaware             1,000             6,949               460
PARKER & PARSLEY PRIVATE INVESTMENT 89, L.P.                     Delaware            40,000             7,060               128
PARKER & PARSLEY 90-A CONV., L.P.                                Delaware             1,000             2,359               139
PARKER & PARSLEY 90-A, L.P.                                      Delaware             1,000             6,811               525
PARKER & PARSLEY 90-B CONV., L.P.                                Delaware             1,000            11,897               664
PARKER & PARSLEY 90-B, L.P.                                      Delaware             1,000            32,264             2,195
PARKER & PARSLEY 90-C CONV., L.P.                                Delaware             1,000             7,531               505
PARKER & PARSLEY 90-C, L.P.                                      Delaware             1,000            12,107               886
PARKER & PARSLEY PRIVATE INVESTMENT 90, L.P.                     Delaware            40,000            10,970               197
PARKER & PARSLEY 90 SPRABERRY PRIVATE DEV., L.P.                 Delaware            40,000             5,200               105
PARKER & PARSLEY 91-A, L.P.                                      Delaware             1,000            11,620               725
PARKER & PARSLEY 91-B, L.P.                                      Delaware             1,000            11,249               681
                                                                                                                ---------------
                               TOTAL                                                                                     28,935
                                                                                                                ===============




                                       A-2
   104




                                     TABLE 2

              MERGER VALUE ATTRIBUTABLE TO PIONEER USA, NONMANAGING
                    GENERAL PARTNERS AND LIMITED PARTNERS (a)






                                                                          NONMANAGING
                                                                            GENERAL        LIMITED
                                                         PIONEER USA (b)  PARTNERS (c)   PARTNERS (d)      TOTAL
                                                         --------------   ------------   ------------   ------------
                                                                                            
PARKER & PARSLEY 81-I, LTD.                                $    225,691   $     16,187   $    628,935   $    870,813
PARKER & PARSLEY 81-II, LTD.                                    142,209          5,774        469,750        617,733
PARKER & PARSLEY 82-I, LTD.                                     384,588         13,293        843,604      1,241,485
PARKER & PARSLEY 82-II, LTD.                                    417,948         12,957      1,198,982      1,629,887
PARKER & PARSLEY 82-III, LTD.                                   305,950          9,928        787,723      1,103,601
PARKER & PARSLEY 83-A, LTD.                                     940,944         37,001      2,662,986      3,640,931
PARKER & PARSLEY 83-B, LTD.                                   1,233,793         48,095      3,472,973      4,754,861
PARKER & PARSLEY 84-A, LTD.                                   1,285,776         56,545      3,830,437      5,172,758
PARKER & PARSLEY 85-A, LTD.                                      41,068           --        1,362,562      1,403,630
PARKER & PARSLEY 85-B, LTD.                                      20,207           --        1,155,401      1,175,608
PARKER & PARSLEY PRIVATE INVESTMENT 85-A, LTD.                   50,076           --        1,433,225      1,483,301
PARKER & PARSLEY SELECTED 85 PRIVATE INVESTMENT, LTD.            24,401           --          883,142        907,543
PARKER & PARSLEY 86-A, LTD.                                      24,320           --        1,787,869      1,812,189
PARKER & PARSLEY 86-B, LTD.                                      67,657           --        3,828,747      3,896,404
PARKER & PARSLEY 86-C, LTD.                                      41,133           --        3,104,794      3,145,927
PARKER & PARSLEY PRIVATE INVESTMENT 86, LTD.                     12,640           --        1,251,314      1,263,954
PARKER & PARSLEY 87-A CONV., LTD.                                14,150           --          731,138        745,288
PARKER & PARSLEY 87-A, LTD.                                      88,920           --        5,463,944      5,552,864
PARKER & PARSLEY 87-B CONV., LTD.                                12,012           --          987,950        999,962
PARKER & PARSLEY 87-B, LTD.                                      49,926           --        4,036,481      4,086,407
PARKER & PARSLEY PRODUCING PROPERTIES 87-A, LTD.                 35,132           --        2,569,999      2,605,131
PARKER & PARSLEY PRODUCING PROPERTIES 87-B, LTD.                 62,154           --        2,336,072      2,398,226
PARKER & PARSLEY PRIVATE INVESTMENT 87, LTD.                     29,502           --        2,920,727      2,950,229
PARKER & PARSLEY 88-A CONV., L.P.                                21,672           --          918,526        940,198
PARKER & PARSLEY 88-A, L.P.                                      74,684           --        3,138,812      3,213,496
PARKER & PARSLEY 88-B CONV., L.P.                                18,200           --        1,160,138      1,178,338
PARKER & PARSLEY 88-B, L.P.                                      59,211           --        2,844,288      2,903,499
PARKER & PARSLEY 88-C CONV., L.P.                                12,256           --          937,636        949,892
PARKER & PARSLEY 88-C, L.P.                                       8,093           --          664,276        672,369
PARKER & PARSLEY PRODUCING PROPERTIES 88-A, L.P.                 34,210           --        1,992,312      2,026,522
PARKER & PARSLEY PRIVATE INVESTMENT 88, L.P.                     34,558           --        3,421,198      3,455,756
PARKER & PARSLEY 89-A CONV., L.P.                                 9,323           --          922,978        932,301
PARKER & PARSLEY 89-A, L.P.                                      62,481           --        2,714,640      2,777,121
PARKER & PARSLEY 89-B CONV., L.P.                                23,671           --        1,777,880      1,801,551
PARKER & PARSLEY 89-B, L.P.                                      40,152           --        1,941,940      1,982,092
PARKER & PARSLEY PRIVATE INVESTMENT 89, L.P.                     30,131           --        1,900,223      1,930,354
PARKER & PARSLEY 90-A CONV., L.P.                                 9,110           --          564,755        573,865
PARKER & PARSLEY 90-A, L.P.                                      52,103           --        1,608,971      1,661,074
PARKER & PARSLEY 90-B CONV., L.P.                                53,040           --        3,131,176      3,184,216
PARKER & PARSLEY 90-B, L.P.                                     108,517           --        8,540,497      8,649,014
PARKER & PARSLEY 90-C CONV., L.P.                                25,877           --        1,829,980      1,855,857
PARKER & PARSLEY 90-C, L.P.                                      36,317           --        2,938,575      2,974,892
PARKER & PARSLEY PRIVATE INVESTMENT 90, L.P.                     53,018           --        3,386,441      3,439,459
PARKER & PARSLEY 90 SPRABERRY PRIVATE DEV., L.P.                 15,154           --        1,500,276      1,515,430
PARKER & PARSLEY 91-A, L.P.                                      65,151           --        4,644,353      4,709,504
PARKER & PARSLEY 91-B, L.P.                                      54,733           --        4,975,820      5,030,553




----------

(a)      The merger value for each partnership is equal to the sum of the
         present value of estimated future net revenues from the partnership's
         estimated oil and gas reserves and its net working capital in each case
         as of March 31, 2001, less its pro rata share, based on its reserve
         value, of the estimated expenses and fees of the mergers of all of the
         partnerships and less the cash distribution on or about July 9, 2001,
         by the partnership to its partners.

(b)      Represents Pioneer USA's partnership interests in each partnership as:
         (1) the sole or managing general partner of the partnership; (2) a
         limited partner of the partnership; and (3) the sole general partner of
         each nonmanaging general partner. Pioneer USA will not receive any
         Pioneer common stock or cash payment for its partnership interests in
         any participating partnership. However, as a result of the merger of
         each participating partnership, Pioneer USA will own 100% of the
         properties of the partnership including properties attributable to its
         partnership interests in the partnership.

(c)      Represents four unaffiliated individuals' partnership interests as
         limited partners of each nonmanaging general partner. Excludes Pioneer
         USA's partnership interests as general partner of each nonmanaging
         general partner.

(d)      Represents the partnership interests of unaffiliated limited partners
         of each partnership. Excludes Pioneer USA's partnership interests as a
         limited partner of any partnership.


                                      A-3
   105



                                     TABLE 3

               MERGER VALUE ATTRIBUTABLE TO PARTNERSHIP INTERESTS
                               OF LIMITED PARTNERS
                              PER $1,000 INVESTMENT





                                                                                  LIMITED PARTNERS
                                                                                PER $1,000 INVESTMENT
                                                      ---------------------------------------------------------------------------
                                                                                              AGGREGATE        LESS
                                                       RESERVE  WORKING CAPITAL    EXPENSES     MERGER      JULY 2001     MERGER
                                                        VALUE       VALUE          AND FEES      VALUE    DISTRIBUTIONS   VALUE
                                                      --------- ---------------   ---------    ---------  ------------- ---------
                                                                                                      
PARKER & PARSLEY 81-I, LTD.                           $   89.88   $    9.32       $   (1.64)   $   97.56   $   (7.43)   $   90.13
PARKER & PARSLEY 81-II, LTD.                              70.80       10.16           (1.29)       79.67       (6.33)       73.34
PARKER & PARSLEY 82-I, LTD.                               79.20        9.69           (1.44)       87.45       (7.39)       80.06
PARKER & PARSLEY 82-II, LTD.                              98.62        9.83           (1.80)      106.65       (5.04)      101.61
PARKER & PARSLEY 82-III, LTD.                            121.37       10.28           (2.21)      129.44       (7.72)      121.72
PARKER & PARSLEY 83-A, LTD.                              137.31       15.18           (2.50)      149.99       (8.56)      141.43
PARKER & PARSLEY 83-B, LTD.                              148.27       17.04           (2.70)      162.61       (8.20)      154.41
PARKER & PARSLEY 84-A, LTD.                              196.55       20.97           (3.58)      213.94      (12.51)      201.43
PARKER & PARSLEY 85-A, LTD.                              140.29       16.15           (2.56)      153.88       (9.33)      144.55
PARKER & PARSLEY 85-B, LTD.                              140.24       17.78           (2.56)      155.46       (9.76)      145.70
PARKER & PARSLEY PRIVATE INVESTMENT 85-A, LTD.           290.83       24.78           (5.30)      310.31      (16.62)      293.69
PARKER & PARSLEY SELECTED 85 PRIVATE INVESTMENT, LTD.    191.78       20.14           (3.50)      208.42      (16.85)      191.57
PARKER & PARSLEY 86-A, LTD.                              170.64       10.64           (3.11)      178.17       (1.08)      177.09
PARKER & PARSLEY 86-B, LTD.                              218.42       22.98           (3.98)      237.42      (13.25)      224.17
PARKER & PARSLEY 86-C, LTD.                              157.16       21.31           (2.86)      175.61      (14.38)      161.23
PARKER & PARSLEY PRIVATE INVESTMENT 86, LTD.             251.34       24.39           (4.58)      271.15      (16.82)      254.33
PARKER & PARSLEY 87-A CONV., LTD.                        185.77       24.00           (3.39)      206.38      (15.03)      191.35
PARKER & PARSLEY 87-A, LTD.                              184.98       24.23           (3.37)      205.84      (15.03)      190.81
PARKER & PARSLEY 87-B CONV., LTD.                        193.71       23.92           (3.53)      214.10      (12.85)      201.25
PARKER & PARSLEY 87-B, LTD.                              193.71       24.05           (3.53)      214.23      (12.85)      201.38
PARKER & PARSLEY PRODUCING PROPERTIES 87-A, LTD.         203.00       32.10           (3.70)      231.40      (20.23)      211.17
PARKER & PARSLEY PRODUCING PROPERTIES 87-B, LTD.         389.13       26.85           (7.09)      408.89      (19.38)      389.51
PARKER & PARSLEY PRIVATE INVESTMENT 87, LTD.             280.46       23.09           (5.11)      298.44      (19.75)      278.69
PARKER & PARSLEY 88-A CONV., L.P.                        238.46       31.69           (4.35)      265.80      (20.40)      245.40
PARKER & PARSLEY 88-A, L.P.                              238.46       32.24           (4.35)      266.35      (20.40)      245.95
PARKER & PARSLEY 88-B CONV., L.P.                        314.31       30.88           (5.73)      339.46      (18.63)      320.83
PARKER & PARSLEY 88-B, L.P.                              314.31       31.07           (5.73)      339.65      (18.63)      321.02
PARKER & PARSLEY 88-C CONV., L.P.                        268.92       28.93           (4.90)      292.95      (17.26)      275.69
PARKER & PARSLEY 88-C, L.P.                              268.92       27.05           (4.90)      291.07      (17.26)      273.81
PARKER & PARSLEY PRODUCING PROPERTIES 88-A, L.P.         325.76       58.49           (5.94)      378.31      (20.76)      357.55
PARKER & PARSLEY PRIVATE INVESTMENT 88, L.P.             337.43       32.64           (6.15)      363.92      (20.42)      343.50
PARKER & PARSLEY 89-A CONV., L.P.                        323.16       33.65           (5.89)      350.92      (20.93)      329.99
PARKER & PARSLEY 89-A, L.P.                              323.16       34.23           (5.89)      351.50      (20.93)      330.57
PARKER & PARSLEY 89-B CONV., L.P.                        275.97       30.92           (5.03)      301.86      (19.07)      282.79
PARKER & PARSLEY 89-B, L.P.                              275.45       31.03           (5.02)      301.46      (19.07)      282.39
PARKER & PARSLEY PRIVATE INVESTMENT 89, L.P.             266.72       27.07           (4.86)      288.93      (18.24)      270.69
PARKER & PARSLEY 90-A CONV., L.P.                        233.70       30.00           (4.26)      259.44      (18.61)      240.83
PARKER & PARSLEY 90-A, L.P.                              233.70       30.61           (4.26)      260.05      (18.61)      241.44
PARKER & PARSLEY 90-B CONV., L.P.                        264.06       26.06           (4.81)      285.31      (20.34)      264.97
PARKER & PARSLEY 90-B, L.P.                              264.28       26.27           (4.82)      285.73      (20.34)      265.39
PARKER & PARSLEY 90-C CONV., L.P.                        240.17       23.39           (4.38)      259.18      (15.22)      243.96
PARKER & PARSLEY 90-C, L.P.                              240.18       22.68           (4.38)      258.48      (15.22)      243.26
PARKER & PARSLEY PRIVATE INVESTMENT 90, L.P.             308.08       28.37           (5.61)      330.84      (20.44)      310.40
PARKER & PARSLEY 90 SPRABERRY PRIVATE DEV., L.P.         288.77       27.40           (5.26)      310.91      (22.40)      288.51
PARKER & PARSLEY 91-A, L.P.                              401.35       33.61           (7.31)      427.65      (26.41)      401.24
PARKER & PARSLEY 91-B, L.P.                              439.13       36.88           (8.00)      468.01      (25.28)      442.73




                                      A-4
   106



                                     TABLE 4

              OWNERSHIP PERCENTAGE AND MERGER VALUE ATTRIBUTABLE TO
               NONMANAGING GENERAL PARTNERS OTHER THAN PIONEER USA






                                                                    NONMANAGING GENERAL                       NONMANAGING
                                                                         PARTNERS (a)                  GENERAL PARTNERS' MERGER
                                                            --------------------------------------     VALUE AS A PERCENTAGE OF
                                                               OWNERSHIP               MERGER                MERGER VALUE
                                                             PERCENTAGE (b)           VALUE (c)        FOR THE PARTNERSHIP (d)
                                                            ----------------      ----------------     ------------------------
                                                                                              
PARKER & PARSLEY 81-I, LTD.                                             2.00%     $         16,187                    1.86%
PARKER & PARSLEY 81-II, LTD.                                            1.00%                5,774                    0.93%
PARKER & PARSLEY 82-I, LTD.                                             1.13%               13,293                    1.07%
PARKER & PARSLEY 82-II, LTD.                                            0.84%               12,957                    0.79%
PARKER & PARSLEY 82-III, LTD.                                           0.94%                9,928                    0.90%
PARKER & PARSLEY 83-A, LTD.                                             1.05%               37,001                    1.02%
PARKER & PARSLEY 83-B, LTD.                                             1.05%               48,095                    1.01%
PARKER & PARSLEY 84-A, LTD.                                             1.13%               56,545                    1.09%




----------

(a)      Represents four unaffiliated individuals' partnership interests as
         limited partners of each nonmanaging general partner. Excludes Pioneer
         USA's partnership interests as general partner of each nonmanaging
         general partner.

(b)      Percentage owned is based upon ownership within the partnership as set
         forth in the revenue sharing provisions of the partnership agreement
         for the partnership.

(c)      See "Method of Determining Merger Value for Each Partnership and Amount
         of Pioneer Common Stock and Cash Offered."

(d)      Represents the dollar amount in the nonmanaging general partners'
         merger value column divided by the merger value for the partnership as
         set forth in Table 2.




                                      A-5
   107



                                     TABLE 5

                      OWNERSHIP PERCENTAGE AND MERGER VALUE
                ATTRIBUTABLE TO PIONEER USA IN ITS CAPACITIES AS
        GENERAL PARTNER, NONMANAGING GENERAL PARTNER AND LIMITED PARTNER







                                                                                                               PIONEER USA'S
                                                                                  PIONEER USA (a)            MERGER VALUE AS A
                                                                      ------------------------------------     PERCENTAGE OF
                                                                        OWNERSHIP             MERGER           MERGER VALUE
                                                                      PERCENTAGE (b)          VALUE (c)     FOR THE PARTNERSHIP (d)
                                                                      ---------------      ---------------  ----------------------
                                                                                                   
PARKER & PARSLEY 81-I, LTD.                                                     27.38%     $       225,691               25.92%
PARKER & PARSLEY 81-II, LTD.                                                    24.41%             142,209               23.02%
PARKER & PARSLEY 82-I, LTD.                                                     31.92%             384,588               30.98%
PARKER & PARSLEY 82-II, LTD.                                                    26.92%             417,948               25.64%
PARKER & PARSLEY 82-III, LTD.                                                   28.54%             305,950               27.72%
PARKER & PARSLEY 83-A, LTD.                                                     26.55%             940,944               25.84%
PARKER & PARSLEY 83-B, LTD.                                                     26.76%           1,233,793               25.95%
PARKER & PARSLEY 84-A, LTD.                                                     25.49%           1,285,776               24.86%
PARKER & PARSLEY 85-A, LTD.                                                      2.93%              41,068                2.93%
PARKER & PARSLEY 85-B, LTD.                                                      1.72%              20,207                1.72%
PARKER & PARSLEY PRIVATE INVESTMENT 85-A, LTD.                                   3.38%              50,076                3.38%
PARKER & PARSLEY SELECTED 85 PRIVATE INVESTMENT, LTD.                            2.69%              24,401                2.69%
PARKER & PARSLEY 86-A, LTD.                                                      1.34%              24,320                1.34%
PARKER & PARSLEY 86-B, LTD.                                                      1.74%              67,657                1.74%
PARKER & PARSLEY 86-C, LTD.                                                      1.31%              41,133                1.31%
PARKER & PARSLEY PRIVATE INVESTMENT 86, LTD.                                     1.00%              12,640                1.00%
PARKER & PARSLEY 87-A CONV., LTD.                                                1.90%              14,150                1.90%
PARKER & PARSLEY 87-A, LTD.                                                      1.60%              88,920                1.60%
PARKER & PARSLEY 87-B CONV., LTD.                                                1.20%              12,012                1.20%
PARKER & PARSLEY 87-B, LTD.                                                      1.22%              49,926                1.22%
PARKER & PARSLEY PRODUCING PROPERTIES 87-A, LTD.                                 1.35%              35,132                1.35%
PARKER & PARSLEY PRODUCING PROPERTIES 87-B, LTD.                                 2.59%              62,154                2.59%
PARKER & PARSLEY PRIVATE INVESTMENT 87, LTD.                                     1.00%              29,502                1.00%
PARKER & PARSLEY 88-A CONV., L.P.                                                2.31%              21,672                2.31%
PARKER & PARSLEY 88-A, L.P.                                                      2.32%              74,684                2.32%
PARKER & PARSLEY 88-B CONV., L.P.                                                1.54%              18,200                1.54%
PARKER & PARSLEY 88-B, L.P.                                                      2.04%              59,211                2.04%
PARKER & PARSLEY 88-C CONV., L.P.                                                1.29%              12,256                1.29%
PARKER & PARSLEY 88-C, L.P.                                                      1.20%               8,093                1.20%
PARKER & PARSLEY PRODUCING PROPERTIES 88-A, L.P.                                 1.69%              34,210                1.69%
PARKER & PARSLEY PRIVATE INVESTMENT 88, L.P.                                     1.00%              34,558                1.00%
PARKER & PARSLEY 89-A CONV., L.P.                                                1.00%               9,323                1.00%
PARKER & PARSLEY 89-A, L.P.                                                      2.25%              62,481                2.25%
PARKER & PARSLEY 89-B CONV., L.P.                                                1.31%              23,671                1.31%
PARKER & PARSLEY 89-B, L.P.                                                      2.03%              40,152                2.03%
PARKER & PARSLEY PRIVATE INVESTMENT 89, L.P.                                     1.56%              30,131                1.56%
PARKER & PARSLEY 90-A CONV., L.P.                                                1.59%               9,110                1.59%
PARKER & PARSLEY 90-A, L.P.                                                      3.14%              52,103                3.14%
PARKER & PARSLEY 90-B CONV., L.P.                                                1.67%              53,040                1.67%
PARKER & PARSLEY 90-B, L.P.                                                      1.25%             108,517                1.25%
PARKER & PARSLEY 90-C CONV., L.P.                                                1.39%              25,877                1.39%
PARKER & PARSLEY 90-C, L.P.                                                      1.22%              36,317                1.22%
PARKER & PARSLEY PRIVATE INVESTMENT 90, L.P.                                     1.54%              53,018                1.54%
PARKER & PARSLEY 90 SPRABERRY PRIVATE DEV., L.P.                                 1.00%              15,154                1.00%
PARKER & PARSLEY 91-A, L.P.                                                      1.38%              65,151                1.38%
PARKER & PARSLEY 91-B, L.P.                                                      1.09%              54,733                1.09%




---------------

(a)      Represents Pioneer USA's partnership interests in each partnership as:
         (1) the sole or managing general partner of the partnership; (2) a
         limited partner of the partnership; and (3) the sole general partner of
         each nonmanaging general partner. Pioneer USA will not receive any
         Pioneer common stock or cash payment for its partnership interests in
         any participating partnership. However, as a result of the merger of
         each participating partnership, Pioneer USA will own 100% of the
         properties of the partnership including properties attributable to its
         partnership interests in the partnership.

(b)      Percentage owned is based upon ownership within the partnership as set
         forth in the revenue sharing provisions of the partnership agreement
         for the partnership.

(c)      See "Method of Determining Merger Value for Each Partnership and Amount
         of Pioneer Common Stock and Cash Offered."

(d)      Represents the dollar amount in Pioneer USA's merger value column
         divided by the merger value for the partnership as set forth in Table
         2.




                                      A-6
   108



                                     TABLE 6

          VOTING PERCENTAGE AND INITIAL INVESTMENT OWNED BY PIONEER USA
                      IN ITS CAPACITY AS A LIMITED PARTNER
                              AS OF MARCH 31, 2001





                                                                                         Initial Investment
                                                                       Pioneer Usa            Owned by
                                                                          Voting           Pioneer Usa (d)
                                                                     Percentage (A) (B)    (In Thousands)
                                                                     ------------------  ------------------
                                                                                     
PARKER & PARSLEY 81-I, LTD.                                                      5.84%     $          433
PARKER & PARSLEY 81-II, LTD.                                                     0.55%                 35
PARKER & PARSLEY 82-I, LTD.                                                     10.73%              1,267
PARKER & PARSLEY 82-II, LTD.                                                     3.69%                452
PARKER & PARSLEY 82-III, LTD.                                                    5.97%                411
PARKER & PARSLEY 83-A, LTD.                                                      3.47%                676
PARKER & PARSLEY 83-B, LTD.                                                      3.75%                877
PARKER & PARSLEY 84-A, LTD.                                                      2.16%                419
PARKER & PARSLEY 85-A, LTD. (c)                                                  0.00%                187
PARKER & PARSLEY 85-B, LTD. (c)                                                  0.00%                 58
PARKER & PARSLEY PRIVATE INVESTMENT 85-A, LTD. (c)                               0.00%                120
PARKER & PARSLEY SELECTED 85 PRIVATE INVESTMENT, LTD. (c)                        0.00%                 80
PARKER & PARSLEY 86-A, LTD.                                                      0.35%                 35
PARKER & PARSLEY 86-B, LTD.                                                      0.74%                128
PARKER & PARSLEY 86-C, LTD.                                                      0.31%                 60
PARKER & PARSLEY PRIVATE INVESTMENT 86, LTD. (c)                                 0.00%                 --
PARKER & PARSLEY 87-A CONV., LTD.                                                0.91%                 35
PARKER & PARSLEY 87-A, LTD.                                                      0.61%                175
PARKER & PARSLEY 87-B CONV., LTD.                                                0.20%                 10
PARKER & PARSLEY 87-B, LTD.                                                      0.22%                 45
PARKER & PARSLEY PRODUCING PROPERTIES 87-A, LTD.                                 0.35%                 43
PARKER & PARSLEY PRODUCING PROPERTIES 87-B, LTD.                                 1.61%                 98
PARKER & PARSLEY PRIVATE INVESTMENT 87, LTD.                                     0.00%                 --
PARKER & PARSLEY 88-A CONV., L.P.                                                1.32%                 50
PARKER & PARSLEY 88-A, L.P.                                                      1.34%                173
PARKER & PARSLEY 88-B CONV., L.P.                                                0.55%                 20
PARKER & PARSLEY 88-B, L.P.                                                      1.05%                 94
PARKER & PARSLEY 88-C CONV., L.P.                                                0.29%                 10
PARKER & PARSLEY 88-C, L.P.                                                      0.21%                  5
PARKER & PARSLEY PRODUCING PROPERTIES 88-A, L.P.                                 0.70%                 39
PARKER & PARSLEY PRIVATE INVESTMENT 88, L.P.                                     0.00%                 --
PARKER & PARSLEY 89-A CONV., L.P.                                                0.00%                 --
PARKER & PARSLEY 89-A, L.P.                                                      1.26%                105
PARKER & PARSLEY 89-B CONV., L.P.                                                0.32%                 20
PARKER & PARSLEY 89-B, L.P.                                                      1.04%                 72
PARKER & PARSLEY PRIVATE INVESTMENT 89, L.P.                                     0.57%                 40
PARKER & PARSLEY 90-A CONV., L.P.                                                0.59%                 14
PARKER & PARSLEY 90-A, L.P.                                                      2.16%                147
PARKER & PARSLEY 90-B CONV., L.P.                                                0.67%                 80
PARKER & PARSLEY 90-B, L.P.                                                      0.26%                 83
PARKER & PARSLEY 90-C CONV., L.P.                                                0.40%                 30
PARKER & PARSLEY 90-C, L.P.                                                      0.22%                 27
PARKER & PARSLEY PRIVATE INVESTMENT 90, L.P.                                     0.55%                 60
PARKER & PARSLEY 90 SPRABERRY PRIVATE DEV., L.P.                                 0.00%                 --
PARKER & PARSLEY 91-A, L.P. (c)                                                  0.00%                 45
PARKER & PARSLEY 91-B, L.P. (c)                                                  0.00%                 10




----------

(a)      Represents Pioneer USA's partnership interests in each partnership as a
         limited partner of the partnership. Pioneer USA will not receive any
         Pioneer common stock or cash payment for its partnership interests in
         any participating partnership. However, as a result of the merger of
         each participating partnership, Pioneer USA will own 100% of the
         properties of the partnership including properties attributable to its
         partnership interests in the partnership.

(b)      Represents percentage of limited partners' vote that Pioneer USA is
         entitled to vote. The voting percentage is calculated by dividing (1)
         Pioneer USA's ownership percentage of the partnership interests held as
         a limited partner, by (2) the percentage of partnership interests held
         by all limited partners in the partnership. For example, if the limited
         partners of a partnership represent 99% of the partnership and Pioneer
         USA owns 5% of the partnership interests as a limited partner in that
         partnership, Pioneer USA's voting percentage is 5.05%.

(c)      Pioneer USA is not entitled to vote partnership interests it holds as
         limited partner in this partnership.

(d)      Represents Pioneer USA's share of the initial investment by limited
         partners as shown on Table 1.




                                      A-7
   109



                                     TABLE 7

     HISTORICAL QUARTERLY PARTNERSHIP DISTRIBUTIONS TO THE LIMITED PARTNERS
                              Per $1,000 Investment
                      From Inception Through July 31, 2001






                                                                              QUARTERLY DISTRIBUTIONS
                                                                                 TO LIMITED PARTNERS
                                                                                PER $1,000 INVESTMENT (a)
                                                          ----------------------------------------------------------------
                                                          Inception  Quarter  Quarter  Quarter   Quarter  Quarter  Quarter
                                                              To      ended    ended    ended    ended     ended    ended
                                                          12/31/98   3/31/99  6/30/99  9/30/99  12/31/99  3/31/00  6/30/00
                                                          ---------  -------  -------  -------  --------  -------  -------
                                                                                              
PARKER & PARSLEY 81-I, LTD.                               $  616.71   $ 0.69   $   --   $ 3.26   $ 2.42   $ 4.24   $ 5.53
PARKER & PARSLEY 81-II, LTD.                                 808.37       --     0.35     1.26     2.71     2.01     2.99
PARKER & PARSLEY 82-I, LTD.                                  946.73     0.62     0.53     2.03     1.09     3.93     4.77
PARKER & PARSLEY 82-II, LTD.                               1,099.24     0.83       --     3.34     3.48     4.98     6.07
PARKER & PARSLEY 82-III, LTD.                                924.16       --     1.69     2.92     5.07     7.49     7.80
PARKER & PARSLEY 83-A, LTD.                                1,264.54       --       --     4.11     5.20     7.22     7.30
PARKER & PARSLEY 83-B, LTD.                                1,458.60     0.96     1.79     4.89     6.30     8.70     9.68
PARKER & PARSLEY 84-A, LTD.                                1,384.63     0.80     2.78     4.69     6.81     8.28    11.17
PARKER & PARSLEY 85-A, LTD.                                  678.73     0.83     1.49     4.98     9.55     7.09    11.26
PARKER & PARSLEY 85-B, LTD.                                  876.32       --     3.17     4.12     7.19     7.95     9.04
PARKER & PARSLEY PRIVATE INVESTMENT 85-A, LTD.               997.86     3.16     5.23     8.79    12.34    15.51    20.44
PARKER & PARSLEY SELECTED 85 PRIVATE INVESTMENT, LTD.        872.24     1.66       --     4.33     6.68     9.18    11.68
PARKER & PARSLEY 86-A, LTD.                                1,279.93     0.79     2.23     6.38     5.82     8.66    11.38
PARKER & PARSLEY 86-B, LTD.                                1,469.69     1.53     5.01     5.85     8.40    10.40    13.08
PARKER & PARSLEY 86-C, LTD.                                1,401.81     0.82     2.38     1.77     7.30     8.35     9.67
PARKER & PARSLEY PRIVATE INVESTMENT 86, LTD.               1,525.50     1.23     1.22     5.88     5.44    14.07     9.36
PARKER & PARSLEY 87-A CONV., LTD.                          1,228.63     1.83     2.20     6.07     7.90    11.58    15.18
PARKER & PARSLEY 87-A, LTD.                                1,228.70     1.83     2.20     6.07     7.90    11.58    15.18
PARKER & PARSLEY 87-B CONV., LTD.                          1,154.18     1.85     2.29     5.50     8.64    10.07    12.58
PARKER & PARSLEY 87-B, LTD.                                1,154.25     1.85     2.29     5.50     8.64    10.07    12.58
PARKER & PARSLEY PRODUCING PROPERTIES 87-A, LTD.             889.65     1.49     0.89     6.21     9.75    10.92    13.50
PARKER & PARSLEY PRODUCING PROPERTIES 87-B, LTD.             956.04     3.97     1.02     8.98    13.99    18.53    24.65
PARKER & PARSLEY PRIVATE INVESTMENT 87, LTD.               1,457.32     2.20     4.09     8.56     9.55    12.55    13.19
PARKER & PARSLEY 88-A CONV., L.P.                            991.51     3.16     3.06     7.97    11.11    12.48    15.67
PARKER & PARSLEY 88-A, L.P.                                  991.61     3.16     3.06     7.97    11.11    12.48    15.67
PARKER & PARSLEY 88-B CONV., L.P.                            966.33     3.44     2.88     8.95    13.65    18.22    20.69
PARKER & PARSLEY 88-B, L.P.                                  966.37     3.44     2.88     8.95    13.65    18.22    20.69
PARKER & PARSLEY 88-C CONV., L.P.                            913.42     3.92     2.34     4.27    11.12    16.38    18.34
PARKER & PARSLEY 88-C, L.P.                                  913.01     3.92     2.34     4.27    11.12    16.38    18.34
PARKER & PARSLEY PRODUCING PROPERTIES 88-A, L.P.           1,075.69     6.51     4.02     7.58    11.34    21.95    19.09
PARKER & PARSLEY PRIVATE INVESTMENT 88, L.P.               1,031.07     3.57     6.66     8.39    12.47    15.99    19.23
PARKER & PARSLEY 89-A CONV., L.P.                            911.13     2.66     2.77     9.16    13.97    17.96    18.39
PARKER & PARSLEY 89-A, L.P.                                  911.19     2.66     2.77     9.16    13.97    17.96    18.39
PARKER & PARSLEY 89-B CONV., L.P.                            787.19     3.26     1.22     8.31    11.43    14.28    18.94
PARKER & PARSLEY 89-B, L.P.                                  787.20     3.26     1.22     8.31    11.43    14.28    18.94
PARKER & PARSLEY PRIVATE INVESTMENT 89, L.P.                 689.19     1.02     1.85     6.67     4.97    13.32    15.00
PARKER & PARSLEY 90-A CONV., L.P.                            784.83     3.18     1.68     8.12     9.46    12.70    14.52
PARKER & PARSLEY 90-A, L.P.                                  784.89     3.18     1.68     8.12     9.46    12.70    14.52
PARKER & PARSLEY 90-B CONV., L.P.                            600.45     2.10     1.80     7.47    11.46    14.98    15.20
PARKER & PARSLEY 90-B, L.P.                                  600.53     2.10     1.80     7.47    11.46    14.98    15.20
PARKER & PARSLEY 90-C CONV., L.P.                            537.51     0.95       --     6.26    10.83    13.62    14.90
PARKER & PARSLEY 90-C, L.P.                                  537.52     0.95       --     6.26    10.83    13.62    14.90
PARKER & PARSLEY PRIVATE INVESTMENT 90, L.P.                 673.63     2.14     3.11     5.62    12.23    15.05    18.11
PARKER & PARSLEY 90 SPRABERRY PRIVATE DEV., L.P.             632.08     3.71     3.09     6.40    13.59    16.68    13.98
PARKER & PARSLEY 91-A, L.P.                                  663.47     3.99     6.33    11.37    15.54    20.76    23.19
PARKER & PARSLEY 91-B, L.P.                                  526.98     3.95     7.05    13.55    18.24    21.87    26.88


                                                                              QUARTERLY DISTRIBUTIONS
                                                                                 TO LIMITED PARTNERS
                                                                                PER $1,000 INVESTMENT (a)
                                                       ---------------------------------------------------------------------------
                                                        Quarter      Quarter      Quarter      Quarter       Month      Inception
                                                         ended        ended         ended       ended        ended         To
                                                        9/30/00      12/31/00      3/31/01      6/30/01     7/31/01      7/31/01
                                                       ----------   ----------   ----------   ----------   ----------   ----------
                                                                                                      
PARKER & PARSLEY 81-I, LTD.                            $     4.53   $     5.41   $     6.91   $       --   $     7.43   $   657.13
PARKER & PARSLEY 81-II, LTD.                                 5.00         5.97         6.88           --         6.33       841.87
PARKER & PARSLEY 82-I, LTD.                                  6.70         4.06         8.08           --         7.39       985.93
PARKER & PARSLEY 82-II, LTD.                                 4.58         6.41         8.01           --         5.04     1,141.98
PARKER & PARSLEY 82-III, LTD.                                9.38         8.84        10.27           --         7.72       985.34
PARKER & PARSLEY 83-A, LTD.                                  9.04        10.25        12.04           --         8.56     1,328.26
PARKER & PARSLEY 83-B, LTD.                                 11.28        10.66        11.10           --         8.20     1,532.16
PARKER & PARSLEY 84-A, LTD.                                 12.41        13.00        14.37           --        12.51     1,471.45
PARKER & PARSLEY 85-A, LTD.                                  9.94        10.41        13.70           --         9.33       757.31
PARKER & PARSLEY 85-B, LTD.                                  9.26        12.47        15.53           --         9.76       954.81
PARKER & PARSLEY PRIVATE INVESTMENT 85-A, LTD.              16.65        16.32        18.72           --        16.62     1,131.64
PARKER & PARSLEY SELECTED 85 PRIVATE INVESTMENT, LTD.       12.92        12.98        18.63           --        16.85       967.15
PARKER & PARSLEY 86-A, LTD.                                 12.54        13.08        18.73           --         1.08     1,360.62
PARKER & PARSLEY 86-B, LTD.                                 14.24        15.95        18.32           --        13.25     1,575.72
PARKER & PARSLEY 86-C, LTD.                                 12.04        12.45        15.95           --        14.38     1,486.92
PARKER & PARSLEY PRIVATE INVESTMENT 86, LTD.                17.03        15.11        22.67           --        16.82     1,634.33
PARKER & PARSLEY 87-A CONV., LTD.                           13.96        12.79        16.86           --        15.03     1,332.03
PARKER & PARSLEY 87-A, LTD.                                 13.96        12.79        16.86           --        15.03     1,332.10
PARKER & PARSLEY 87-B CONV., LTD.                           13.53        12.84        17.13           --        12.85     1,251.46
PARKER & PARSLEY 87-B, LTD.                                 13.53        12.84        17.13           --        12.85     1,251.53
PARKER & PARSLEY PRODUCING PROPERTIES 87-A, LTD.            12.12        14.11        21.51           --        20.23     1,000.38
PARKER & PARSLEY PRODUCING PROPERTIES 87-B, LTD.            26.75        26.21        27.53           --        19.38     1,127.05
PARKER & PARSLEY PRIVATE INVESTMENT 87, LTD.                14.14        16.03        18.36           --        19.75     1,575.74
PARKER & PARSLEY 88-A CONV., L.P.                           17.33        16.95        20.80           --        20.40     1,120.44
PARKER & PARSLEY 88-A, L.P.                                 17.33        16.95        20.80           --        20.40     1,120.54
PARKER & PARSLEY 88-B CONV., L.P.                           22.63        25.37        28.91           --        18.63     1,129.70
PARKER & PARSLEY 88-B, L.P.                                 22.63        25.37        28.91           --        18.63     1,129.74
PARKER & PARSLEY 88-C CONV., L.P.                           19.83        21.01        24.91           --        17.26     1,052.80
PARKER & PARSLEY 88-C, L.P.                                 19.83        21.01        24.91           --        17.26     1,052.39
PARKER & PARSLEY PRODUCING PROPERTIES 88-A, L.P.            18.82        21.76        27.21           --        20.76     1,234.73
PARKER & PARSLEY PRIVATE INVESTMENT 88, L.P.                23.09        21.51        23.55           --        20.42     1,185.95
PARKER & PARSLEY 89-A CONV., L.P.                           20.40        23.38        29.49           --        20.93     1,070.24
PARKER & PARSLEY 89-A, L.P.                                 20.40        23.38        29.49           --        20.93     1,070.30
PARKER & PARSLEY 89-B CONV., L.P.                           20.23        20.99        26.50           --        19.07       931.42
PARKER & PARSLEY 89-B, L.P.                                 20.23        20.99        26.50           --        19.07       931.43
PARKER & PARSLEY PRIVATE INVESTMENT 89, L.P.                16.66        20.33        13.22           --        18.24       800.47
PARKER & PARSLEY 90-A CONV., L.P.                           17.43        19.18        19.99           --        18.61       909.70
PARKER & PARSLEY 90-A, L.P.                                 17.43        19.18        19.99           --        18.61       909.76
PARKER & PARSLEY 90-B CONV., L.P.                           19.51        19.68        23.73           --        20.34       736.72
PARKER & PARSLEY 90-B, L.P.                                 19.51        19.68        23.73           --        20.34       736.80
PARKER & PARSLEY 90-C CONV., L.P.                           19.01        17.84        21.19           --        15.22       657.33
PARKER & PARSLEY 90-C, L.P.                                 19.01        17.84        21.18           --        15.22       657.33
PARKER & PARSLEY PRIVATE INVESTMENT 90, L.P.                20.29        25.10        27.49           --        20.44       823.21
PARKER & PARSLEY 90 SPRABERRY PRIVATE DEV., L.P.            14.00        13.98        20.44           --        22.40       760.35
PARKER & PARSLEY 91-A, L.P.                                 26.03        30.05        27.29           --        26.41       854.43
PARKER & PARSLEY 91-B, L.P.                                 33.92        35.07        24.81           --        25.28       737.60




----------


(a) Past cash distributions to limited partners are not necessarily indicative
of future cash distributions. Limited partners should not assume that any
nonparticipating partnership will continue to make cash distributions at levels
similar to those shown. See "The Merger of Each Partnership - Distribution of
Pioneer Common Stock and Cash Payment."



                                      A-8
   110


                                     TABLE 8
        ANNUAL REPURCHASE PRICES AND AGGREGATE ANNUAL REPURCHASE PAYMENTS






                                                2001                     2000                      1999
                                      -----------------------   -----------------------   -----------------------
                                      REPURCHASE    AGGREGATE    REPURCHASE   AGGREGATE   REPURCHASE   AGGREGATE
                                        PRICE        ANNUAL       PRICE        ANNUAL       PRICE        ANNUAL
                                      PER $1,000   REPURCHASE   PER $1,000   REPURCHASE   PER $1,000   REPURCHASE
                                      INVESTMENT    PAYMENTS    INVESTMENT    PAYMENTS    INVESTMENT    PAYMENTS
                                      ----------   ----------   ----------   ----------   ----------   ----------
                                                                                     
PARKER & PARSLEY 82-I, LTD.           $   137.97          (a)   $    71.89   $    4,745   $     7.52   $       94
PARKER & PARSLEY 82-II, LTD.              133.72          (a)       102.38        1,024        26.17          131
PARKER & PARSLEY 82-III, LTD.             150.59          (a)       109.73        1,097        12.17          284
PARKER & PARSLEY 83-A, LTD.               196.67          (a)       137.59        9,494        27.05          541
PARKER & PARSLEY 83-B, LTD.               210.15          (a)       153.89        3,078        43.46           --
PARKER & PARSLEY 84-A, LTD.               267.03          (a)       175.78        7,031        45.72        1,143
                                                                                          ----------   ----------
                                                                                          $   26,469   $    2,193
                                                                                          ==========   ==========




----------

(a)      Payments will not be made until the third quarter of 2001.



                                      A-9
   111


                                     TABLE 9

                       PARTICIPATION IN COSTS AND REVENUES
                               OF EACH PARTNERSHIP





                                                             CAPITAL COSTS                         REVENUES AND EXPENSES
                                                ---------------------------------------  --------------------------------------
                                                                            NONMANAGING                  NONMANAGING
                                                 GENERAL        GENERAL        LIMITED       GENERAL       GENERAL      LIMITED
                                                PARTNER (a)   PARTNERS (a)   PARTNERS (a)   PARTNER (a)  PARTNERS (a) PARTNERS (a)
                                                ----------   -------------  ------------  -------------  ------------ ------------
                                                                                                    
PARKER & PARSLEY 81-I, LTD.                              8%              2%          90%            20%           5%          75%
PARKER & PARSLEY 81-II, LTD.                             8%              2%          90%            20%           5%          75%
PARKER & PARSLEY 82-I, LTD.                              8%              2%          90%            20%           5%          75%
PARKER & PARSLEY 82-II, LTD.                             8%              2%          90%            20%           5%          75%
PARKER & PARSLEY 82-III, LTD.                            8%              2%          90%            20%           5%          75%
PARKER & PARSLEY 83-A, LTD. (b)                          8%              2%          90%            20%           5%          75%
PARKER & PARSLEY 83-B, LTD. (b)                          8%              2%          90%            20%           5%          75%
PARKER & PARSLEY 84-A, LTD. (b)                          8%              2%          90%            20%           5%          75%
PARKER & PARSLEY 85-A, LTD.                              1%             --           99%             1%          --           99%
PARKER & PARSLEY 85-B, LTD.                              1%             --           99%             1%          --           99%
PARKER & PARSLEY PRIVATE INVESTMENT 85-A, LTD.           1%             --           99%             1%          --           99%
PARKER & PARSLEY SELECTED 85 PRIVATE
  INVESTMENT, LTD.                                       1%             --           99%             1%          --           99%
PARKER & PARSLEY 86-A, LTD.                              1%             --           99%             1%          --           99%
PARKER & PARSLEY 86-B, LTD.                              1%             --           99%             1%          --           99%
PARKER & PARSLEY 86-C, LTD.                              1%             --           99%             1%          --           99%
PARKER & PARSLEY PRIVATE INVESTMENT 86, LTD.             1%             --           99%             1%          --           99%
PARKER & PARSLEY 87-A CONV., LTD.                        1%             --           99%             1%          --           99%
PARKER & PARSLEY 87-A, LTD.                              1%             --           99%             1%          --           99%
PARKER & PARSLEY 87-B CONV., LTD.                        1%             --           99%             1%          --           99%
PARKER & PARSLEY 87-B, LTD.                              1%             --           99%             1%          --           99%
PARKER & PARSLEY PRODUCING PROPERTIES 87-A, LTD.         1%             --           99%             1%          --           99%
PARKER & PARSLEY PRODUCING PROPERTIES 87-B, LTD.         1%             --           99%             1%          --           99%
PARKER & PARSLEY PRIVATE INVESTMENT 87, LTD.             1%             --           99%             1%          --           99%
PARKER & PARSLEY 88-A CONV., L.P.                        1%             --           99%             1%          --           99%
PARKER & PARSLEY 88-A, L.P.                              1%             --           99%             1%          --           99%
PARKER & PARSLEY 88-B CONV., L.P.                        1%             --           99%             1%          --           99%
PARKER & PARSLEY 88-B, L.P.                              1%             --           99%             1%          --           99%
PARKER & PARSLEY 88-C CONV., L.P.                        1%             --           99%             1%          --           99%
PARKER & PARSLEY 88-C, L.P.                              1%             --           99%             1%          --           99%
PARKER & PARSLEY PRODUCING PROPERTIES 88-A, L.P.         1%             --           99%             1%          --           99%
PARKER & PARSLEY PRIVATE INVESTMENT 88, L.P.             1%             --           99%             1%          --           99%
PARKER & PARSLEY 89-A CONV., L.P.                        1%             --           99%             1%          --           99%
PARKER & PARSLEY 89-A, L.P.                              1%             --           99%             1%          --           99%
PARKER & PARSLEY 89-B CONV., L.P.                        1%             --           99%             1%          --           99%
PARKER & PARSLEY 89-B, L.P.                              1%             --           99%             1%          --           99%
PARKER & PARSLEY PRIVATE INVESTMENT 89, L.P.             1%             --           99%             1%          --           99%
PARKER & PARSLEY 90-A CONV., L.P.                        1%             --           99%             1%          --           99%
PARKER & PARSLEY 90-A, L.P.                              1%             --           99%             1%          --           99%
PARKER & PARSLEY 90-B CONV., L.P.                        1%             --           99%             1%          --           99%
PARKER & PARSLEY 90-B, L.P.                              1%             --           99%             1%          --           99%
PARKER & PARSLEY 90-C CONV., L.P.                        1%             --           99%             1%          --           99%
PARKER & PARSLEY 90-C, L.P.                              1%             --           99%             1%          --           99%
PARKER & PARSLEY PRIVATE INVESTMENT 90, L.P.             1%             --           99%             1%          --           99%
PARKER & PARSLEY 90 SPRABERRY PRIVATE DEV., L.P.         1%             --           99%             1%          --           99%
PARKER & PARSLEY 91-A, L.P.                              1%             --           99%             1%          --           99%
PARKER & PARSLEY 91-B, L.P.                              1%             --           99%             1%          --           99%




----------

(a)      These percentages represent the sharing ownerships as set forth in the
         prospectus for each partnership. Includes Pioneer USA's partnership
         interests in each partnership as: (1) the sole or managing general
         partner of the partnership; (2) a limited partner of the partnership;
         and (3) the sole general partner of each nonmanaging general partner.
         Pioneer USA will not receive any Pioneer common stock or cash payment
         for its partnership interests in any participating partnership.

(b)      Incremental direct costs 100% to limited partners.



                                      A-10
   112


                                    TABLE 10

   AVERAGE OIL, NATURAL GAS LIQUIDS AND GAS SALES PRICES AND PRODUCTION COSTS
                  FOR THE THREE MONTHS ENDED MARCH 31, 2001 AND
           2000 AND THE YEARS ENDED DECEMBER 31, 2000, 1999 AND 1998





                                                                              AVERAGE SALES PRICE
                                                        --------------------------------------------------------------
                                                                                 OIL (PER BBL)
                                                        --------------------------------------------------------------
                                                         FOR THE THREE MONTHS              FOR THE YEAR ENDED
                                                             ENDED MARCH 31,                   DECEMBER 31,
                                                           2001         2000         2000         1999         1998
                                                        ----------   ----------   ----------   ----------   ----------
                                                                                             
PARKER & PARSLEY 81-I, LTD.                             $    28.55   $    27.16   $    29.26   $    16.94   $    13.33
PARKER & PARSLEY 81-II, LTD.                                 27.86        27.34        29.26        16.67        13.16
PARKER & PARSLEY 82-I, LTD.                                  28.02        27.23        29.39        16.61        13.32
PARKER & PARSLEY 82-II, LTD.                                 28.12        27.27        29.47        17.08        13.14
PARKER & PARSLEY 82-III, LTD.                                28.58        27.64        29.67        17.13        13.31
PARKER & PARSLEY 83-A, LTD.                                  28.05        27.44        29.54        16.96        13.34
PARKER & PARSLEY 83-B, LTD.                                  28.39        27.66        29.69        17.18        13.30
PARKER & PARSLEY 84-A, LTD.                                  27.16        27.61        29.55        17.36        13.30
PARKER & PARSLEY 85-A, LTD.                                  28.29        27.40        29.38        17.11        13.27
PARKER & PARSLEY 85-B, LTD.                                  28.85        28.65        30.02        18.07        13.30
PARKER & PARSLEY PRIVATE INVESTMENT 85-A, LTD.               28.73        27.36        30.19        16.91        13.20
PARKER & PARSLEY SELECTED 85 PRIVATE INVESTMENT, LTD.        28.33        27.34        29.59        17.27        13.44
PARKER & PARSLEY 86-A, LTD.                                  28.20        27.46        28.87        17.00        13.32
PARKER & PARSLEY 86-B, LTD.                                  28.95        27.60        29.45        17.18        13.08
PARKER & PARSLEY 86-C, LTD.                                  27.96        27.56        29.43        17.18        13.26
PARKER & PARSLEY PRIVATE INVESTMENT 86, LTD.                 28.55        27.55        29.45        17.34        13.34
PARKER & PARSLEY 87-A CONV., LTD.                            27.84        27.18        29.46        17.06        13.22
PARKER & PARSLEY 87-A, LTD.                                  27.84        27.18        29.46        17.06        13.22
PARKER & PARSLEY 87-B CONV., LTD.                            27.55        27.69        29.31        16.71        13.17
PARKER & PARSLEY 87-B, LTD.                                  27.55        27.69        29.31        16.71        13.17
PARKER & PARSLEY PRODUCING PROPERTIES 87-A, LTD.             27.48        27.47        29.34        16.80        13.04
PARKER & PARSLEY PRODUCING PROPERTIES 87-B, LTD.             27.14        27.54        29.36        17.44        13.05
PARKER & PARSLEY PRIVATE INVESTMENT 87, LTD.                 27.13        27.10        29.56        16.82        13.05
PARKER & PARSLEY 88-A CONV., L.P.                            25.98        27.90        29.28        16.91        13.59
PARKER & PARSLEY 88-A, L.P.                                  25.98        27.90        29.28        16.91        13.59
PARKER & PARSLEY 88-B CONV., L.P.                            29.80        26.41        29.29        17.17        13.24
PARKER & PARSLEY 88-B, L.P.                                  29.80        26.41        29.29        17.17        13.24
PARKER & PARSLEY 88-C CONV., L.P.                            30.11        26.37        29.33        17.24        13.30
PARKER & PARSLEY 88-C, L.P.                                  30.11        26.37        29.33        17.24        13.30
PARKER & PARSLEY PRODUCING PROPERTIES 88-A, L.P.             27.40        27.98        29.44        16.82        13.14
PARKER & PARSLEY PRIVATE INVESTMENT 88, L.P.                 27.93        27.22        29.45        17.01        13.31
PARKER & PARSLEY 89-A CONV., L.P.                            28.10        27.48        29.59        17.11        13.23
PARKER & PARSLEY 89-A, L.P.                                  28.10        27.48        29.59        17.11        13.23
PARKER & PARSLEY 89-B CONV., L.P.                            28.41        27.13        29.21        16.96        13.26
PARKER & PARSLEY 89-B, L.P.                                  28.41        27.13        29.21        16.96        13.26
PARKER & PARSLEY PRIVATE INVESTMENT 89, L.P.                 27.47        26.78        29.00        17.06        13.28
PARKER & PARSLEY 90-A CONV., L.P.                            28.38        27.38        29.32        17.06        13.20
PARKER & PARSLEY 90-A, L.P.                                  28.38        27.38        29.32        17.06        13.20
PARKER & PARSLEY 90-B CONV., L.P.                            29.26        27.70        29.23        17.23        13.12
PARKER & PARSLEY 90-B, L.P.                                  29.26        27.70        29.23        17.23        13.12
PARKER & PARSLEY 90-C CONV., L.P.                            28.08        27.16        29.34        17.13        13.24
PARKER & PARSLEY 90-C, L.P.                                  28.08        27.16        29.34        17.13        13.24
PARKER & PARSLEY PRIVATE INVESTMENT 90, L.P.                 28.27        27.27        29.35        17.30        13.19
PARKER & PARSLEY 90 SPRABERRY PRIVATE DEV., L.P.             27.96        26.99        29.17        17.04        13.06
PARKER & PARSLEY 91-A, L.P.                                  27.99        27.88        29.90        17.57        13.15
PARKER & PARSLEY 91-B, L.P.                                  28.83        28.53        30.09        17.90        13.33



                                                                              AVERAGE SALES PRICE
                                                        --------------------------------------------------------------
                                                                                  NGL (PER BBL)
                                                         -------------------------------------------------------------
                                                           FOR THE THREE MONTHS              FOR THE YEAR ENDED
                                                              ENDED MARCH 31,                   DECEMBER 31,
                                                            2001         2000         2000         1999        1998
                                                         ----------   ----------   ----------   ----------   ----------
                                                                                              
PARKER & PARSLEY 81-I, LTD.                              $    16.71   $    14.58   $    14.60   $     9.22   $     6.40
PARKER & PARSLEY 81-II, LTD.                                  20.90        17.54        15.59         8.70         6.73
PARKER & PARSLEY 82-I, LTD.                                   19.68        12.67        14.44         8.96         7.20
PARKER & PARSLEY 82-II, LTD.                                  19.54        13.18        15.01         9.80         6.93
PARKER & PARSLEY 82-III, LTD.                                 16.89        12.20        13.86         9.13         6.42
PARKER & PARSLEY 83-A, LTD.                                   19.07        14.18        15.58         9.42         6.49
PARKER & PARSLEY 83-B, LTD.                                   18.66        13.48        15.47        10.00         6.79
PARKER & PARSLEY 84-A, LTD.                                   16.20        12.70        14.00         9.03         6.08
PARKER & PARSLEY 85-A, LTD.                                   17.68        12.16        14.20         9.71         6.51
PARKER & PARSLEY 85-B, LTD.                                   18.94        14.41        15.96        10.10         6.95
PARKER & PARSLEY PRIVATE INVESTMENT 85-A, LTD.                17.26        13.27        15.22         9.95         6.49
PARKER & PARSLEY SELECTED 85 PRIVATE INVESTMENT, LTD.         18.19        13.50        15.52        10.49         6.99
PARKER & PARSLEY 86-A, LTD.                                   18.84        13.90        14.94         9.63         6.53
PARKER & PARSLEY 86-B, LTD.                                   19.15        13.37        15.00         9.39         6.80
PARKER & PARSLEY 86-C, LTD.                                   18.08        13.64        15.06         9.27         6.46
PARKER & PARSLEY PRIVATE INVESTMENT 86, LTD.                  18.32        13.33        15.01         9.27         6.69
PARKER & PARSLEY 87-A CONV., LTD.                             18.62        15.12        16.01         9.81         6.76
PARKER & PARSLEY 87-A, LTD.                                   18.62        15.12        16.01         9.81         6.76
PARKER & PARSLEY 87-B CONV., LTD.                             18.92        15.18        16.90         9.73         6.82
PARKER & PARSLEY 87-B, LTD.                                   18.92        15.18        16.90         9.73         6.82
PARKER & PARSLEY PRODUCING PROPERTIES 87-A, LTD.              13.37        11.93        12.12         7.32         5.46
PARKER & PARSLEY PRODUCING PROPERTIES 87-B, LTD.              19.07        14.93        16.68        10.32         6.58
PARKER & PARSLEY PRIVATE INVESTMENT 87, LTD.                  19.52        14.77        16.17         9.41         6.55
PARKER & PARSLEY 88-A CONV., L.P.                             18.12        13.93        15.30         9.30         6.57
PARKER & PARSLEY 88-A, L.P.                                   18.12        13.93        15.30         9.30         6.57
PARKER & PARSLEY 88-B CONV., L.P.                             19.97        14.34        16.02        10.03         6.91
PARKER & PARSLEY 88-B, L.P.                                   19.97        14.34        16.02        10.03         6.91
PARKER & PARSLEY 88-C CONV., L.P.                             19.45        14.26        15.83        10.42         6.94
PARKER & PARSLEY 88-C, L.P.                                   19.45        14.26        15.83        10.42         6.94
PARKER & PARSLEY PRODUCING PROPERTIES 88-A, L.P.              16.07        13.03        14.28         9.18         6.31
PARKER & PARSLEY PRIVATE INVESTMENT 88, L.P.                  18.85        14.02        15.61         9.32         6.79
PARKER & PARSLEY 89-A CONV., L.P.                             17.36        13.84        15.42         9.54         6.95
PARKER & PARSLEY 89-A, L.P.                                   17.36        13.84        15.42         9.54         6.95
PARKER & PARSLEY 89-B CONV., L.P.                             19.38        14.82        15.56         9.57         6.94
PARKER & PARSLEY 89-B, L.P.                                   19.38        14.82        15.56         9.57         6.94
PARKER & PARSLEY PRIVATE INVESTMENT 89, L.P.                  16.74        11.59        14.86         8.69         6.57
PARKER & PARSLEY 90-A CONV., L.P.                             19.39        13.78        15.62         9.58         7.02
PARKER & PARSLEY 90-A, L.P.                                   19.39        13.78        15.62         9.58         7.02
PARKER & PARSLEY 90-B CONV., L.P.                             18.25        13.89        15.45         9.49         6.60
PARKER & PARSLEY 90-B, L.P.                                   18.25        13.89        15.45         9.49         6.60
PARKER & PARSLEY 90-C CONV., L.P.                             18.95        12.95        14.91         9.31         6.80
PARKER & PARSLEY 90-C, L.P.                                   18.95        12.95        14.91         9.31         6.80
PARKER & PARSLEY PRIVATE INVESTMENT 90, L.P.                  19.81        14.06        15.82         9.46         6.77
PARKER & PARSLEY 90 SPRABERRY PRIVATE DEV., L.P.              19.29        14.49        15.56         9.70         6.89
PARKER & PARSLEY 91-A, L.P.                                   14.86        13.65        14.94         9.34         6.44
PARKER & PARSLEY 91-B, L.P.                                   18.47        15.13        16.50        10.15         6.79






                                                                           AVERAGE SALES PRICE
                                                     -------------------------------------------------------------
                                                                              GAS (PER MCF)
                                                     -------------------------------------------------------------
                                                     FOR THE THREE MONTHS            FOR THE YEAR ENDED
                                                        ENDED MARCH 31,                  DECEMBER 31,
                                                       2001         2000          2000       1999          1998
                                                     ---------   ----------   ----------   ----------   ----------
                                                                                         
PARKER & PARSLEY 81-I, LTD.                               6.07   $     1.83   $     3.22   $     1.78   $     1.78
PARKER & PARSLEY 81-II, LTD.                              6.36         1.26         3.07         1.82         1.80
PARKER & PARSLEY 82-I, LTD.                               5.65         2.33         3.29         1.95         1.82
PARKER & PARSLEY 82-II, LTD.                              5.65         1.90         2.98         1.79         1.64
PARKER & PARSLEY 82-III, LTD.                             5.49         1.60         2.54         1.65         1.53
PARKER & PARSLEY 83-A, LTD.                               5.93         1.76         3.02         1.78         1.60
PARKER & PARSLEY 83-B, LTD.                               5.74         1.76         2.83         1.66         1.54
PARKER & PARSLEY 84-A, LTD.                               4.80         1.54         2.49         1.47         1.33
PARKER & PARSLEY 85-A, LTD.                               5.42         1.71         2.66         1.70         1.56
PARKER & PARSLEY 85-B, LTD.                               5.77         1.84         2.92         1.72         1.58
PARKER & PARSLEY PRIVATE INVESTMENT 85-A, LTD.            5.42         1.58         2.65         1.54         1.41
PARKER & PARSLEY SELECTED 85 PRIVATE INVESTMENT, LTD.     5.37         1.70         2.77         1.67         1.56
PARKER & PARSLEY 86-A, LTD.                               5.76         1.63         2.56         1.57         1.46
PARKER & PARSLEY 86-B, LTD.                               6.27         1.76         2.82         1.71         1.58
PARKER & PARSLEY 86-C, LTD.                               5.59         1.62         2.78         1.58         1.49
PARKER & PARSLEY PRIVATE INVESTMENT 86, LTD.              5.70         1.81         2.90         1.73         1.61
PARKER & PARSLEY 87-A CONV., LTD.                         5.51         1.75         2.86         1.68         1.54
PARKER & PARSLEY 87-A, LTD.                               5.51         1.75         2.86         1.68         1.54
PARKER & PARSLEY 87-B CONV., LTD.                         6.24         1.75         2.98         1.64         1.49
PARKER & PARSLEY 87-B, LTD.                               6.24         1.75         2.98         1.64         1.49
PARKER & PARSLEY PRODUCING PROPERTIES 87-A, LTD.          4.69         1.84         2.56         1.46         1.23
PARKER & PARSLEY PRODUCING PROPERTIES 87-B, LTD.          5.93         1.78         2.88         1.62         1.46
PARKER & PARSLEY PRIVATE INVESTMENT 87, LTD.              6.07         1.86         2.99         1.71         1.59
PARKER & PARSLEY 88-A CONV., L.P.                         4.62         1.73         2.99         1.69         1.56
PARKER & PARSLEY 88-A, L.P.                               4.62         1.73         2.99         1.69         1.56
PARKER & PARSLEY 88-B CONV., L.P.                         9.14         1.73         2.87         1.70         1.56
PARKER & PARSLEY 88-B, L.P.                               9.14         1.73         2.87         1.70         1.56
PARKER & PARSLEY 88-C CONV., L.P.                         8.12         1.70         2.82         1.70         1.55
PARKER & PARSLEY 88-C, L.P.                               8.12         1.70         2.82         1.70         1.55
PARKER & PARSLEY PRODUCING PROPERTIES 88-A, L.P.          5.11         1.53         2.55         1.48         1.41
PARKER & PARSLEY PRIVATE INVESTMENT 88, L.P.              6.05         1.75         2.82         1.69         1.55
PARKER & PARSLEY 89-A CONV., L.P.                         6.16         1.91         3.07         1.81         1.74
PARKER & PARSLEY 89-A, L.P.                               6.16         1.91         3.07         1.81         1.74
PARKER & PARSLEY 89-B CONV., L.P.                         5.95         1.79         2.90         1.72         1.60
PARKER & PARSLEY 89-B, L.P.                               5.95         1.79         2.90         1.72         1.60
PARKER & PARSLEY PRIVATE INVESTMENT 89, L.P.              5.45         1.56         2.73         1.57         1.46
PARKER & PARSLEY 90-A CONV., L.P.                         6.12         1.82         2.94         1.76         1.64
PARKER & PARSLEY 90-A, L.P.                               6.12         1.82         2.94         1.76         1.64
PARKER & PARSLEY 90-B CONV., L.P.                         5.76         1.68         2.84         1.62         1.50
PARKER & PARSLEY 90-B, L.P.                               5.76         1.68         2.84         1.62         1.50
PARKER & PARSLEY 90-C CONV., L.P.                         6.33         1.71         2.89         1.70         1.55
PARKER & PARSLEY 90-C, L.P.                               6.33         1.71         2.89         1.70         1.55
PARKER & PARSLEY PRIVATE INVESTMENT 90, L.P.              6.09         1.77         2.90         1.72         1.57
PARKER & PARSLEY 90 SPRABERRY PRIVATE DEV., L.P.          5.91         1.68         2.91         1.65         1.60
PARKER & PARSLEY 91-A, L.P.                               6.25         1.81         3.06         1.70         1.56
PARKER & PARSLEY 91-B, L.P.                               6.43         1.73         2.93         1.61         1.47




                                                                   AVERAGE PRODUCTION COSTS (LIFTING)
                                                     -------------------------------------------------------------
                                                                       COST PER EQUIVALENT BBL (a)
                                                     -------------------------------------------------------------
                                                      FOR THE THREE MONTHS            FOR THE YEAR ENDED
                                                        ENDED MARCH 31,                   DECEMBER 31,
                                                       2001         2000         2000         1999          1998
                                                     ---------   ----------   ----------   ----------   ----------
                                                                                         
PARKER & PARSLEY 81-I, LTD.                              11.67   $     8.77   $     9.52   $     8.39   $     8.74
PARKER & PARSLEY 81-II, LTD.                             13.89        16.26        11.46         8.57         8.80
PARKER & PARSLEY 82-I, LTD.                              13.01        10.27        11.91         9.80         9.88
PARKER & PARSLEY 82-II, LTD.                             13.90         9.34        10.25         8.09         7.88
PARKER & PARSLEY 82-III, LTD.                            12.40         7.80         9.20         8.06         9.00
PARKER & PARSLEY 83-A, LTD.                              12.81        10.68        10.52         8.64         8.76
PARKER & PARSLEY 83-B, LTD.                              13.44         8.42         9.12         7.60         8.27
PARKER & PARSLEY 84-A, LTD.                               9.71         7.95         8.64         7.70         7.66
PARKER & PARSLEY 85-A, LTD.                              10.51         9.78         9.66         7.02         8.70
PARKER & PARSLEY 85-B, LTD.                               9.58         9.21        10.19         7.70         8.48
PARKER & PARSLEY PRIVATE INVESTMENT 85-A, LTD.            8.44         7.02         7.78         6.40         6.96
PARKER & PARSLEY SELECTED 85 PRIVATE INVESTMENT, LTD.    10.42         8.91         9.43         8.01         7.82
PARKER & PARSLEY 86-A, LTD.                              12.39         8.67         8.86         7.83         9.36
PARKER & PARSLEY 86-B, LTD.                              11.17         8.77         8.87         7.89         7.64
PARKER & PARSLEY 86-C, LTD.                              10.92        10.72        10.31         8.66         7.67
PARKER & PARSLEY PRIVATE INVESTMENT 86, LTD.             11.57        10.78        10.84         9.08         7.67
PARKER & PARSLEY 87-A CONV., LTD.                         9.79         8.31         9.11         7.19         7.78
PARKER & PARSLEY 87-A, LTD.                               9.79         8.31         9.11         7.19         7.78
PARKER & PARSLEY 87-B CONV., LTD.                        11.92         7.45         8.63         7.44         6.65
PARKER & PARSLEY 87-B, LTD.                              11.92         7.45         8.63         7.44         6.65
PARKER & PARSLEY PRODUCING PROPERTIES 87-A, LTD.         11.49        10.34        12.48         8.97         9.26
PARKER & PARSLEY PRODUCING PROPERTIES 87-B, LTD.          9.97         8.79         8.42         8.30         7.84
PARKER & PARSLEY PRIVATE INVESTMENT 87, LTD.             10.31         9.30         9.13         6.77         6.81
PARKER & PARSLEY 88-A CONV., L.P.                         8.33        10.22         8.85         5.98         7.06
PARKER & PARSLEY 88-A, L.P.                               8.33        10.22         8.85         5.98         7.06
PARKER & PARSLEY 88-B CONV., L.P.                         9.94         6.52         7.84         7.04         7.51
PARKER & PARSLEY 88-B, L.P.                               9.94         6.52         7.84         7.04         7.51
PARKER & PARSLEY 88-C CONV., L.P.                         9.68         7.37         8.10         7.43         7.84
PARKER & PARSLEY 88-C, L.P.                               9.68         7.37         8.10         7.43         7.84
PARKER & PARSLEY PRODUCING PROPERTIES 88-A, L.P.          8.45         9.70         9.69         6.31         5.87
PARKER & PARSLEY PRIVATE INVESTMENT 88, L.P.             10.03         8.20         7.57         6.04         6.60
PARKER & PARSLEY 89-A CONV., L.P.                         8.42         7.97         8.23         6.75         6.92
PARKER & PARSLEY 89-A, L.P.                               8.42         7.97         8.23         6.75         6.92
PARKER & PARSLEY 89-B CONV., L.P.                         9.95         8.45         8.59         7.58         7.30
PARKER & PARSLEY 89-B, L.P.                               9.95         8.45         8.59         7.58         7.30
PARKER & PARSLEY PRIVATE INVESTMENT 89, L.P.             15.47         8.91         8.99         8.69         6.80
PARKER & PARSLEY 90-A CONV., L.P.                         9.33         7.92         9.43         7.38         6.93
PARKER & PARSLEY 90-A, L.P.                               9.33         7.92         9.43         7.38         6.93
PARKER & PARSLEY 90-B CONV., L.P.                         9.44         8.57         8.68         7.28         7.31
PARKER & PARSLEY 90-B, L.P.                               9.44         8.57         8.68         7.28         7.31
PARKER & PARSLEY 90-C CONV., L.P.                        11.92         9.49         8.83         7.93         8.22
PARKER & PARSLEY 90-C, L.P.                              11.92         9.49         8.83         7.93         8.22
PARKER & PARSLEY PRIVATE INVESTMENT 90, L.P.              8.66         7.39         8.22         7.01         8.24
PARKER & PARSLEY 90 SPRABERRY PRIVATE DEV., L.P.          8.20         9.35         8.97         7.41         7.44
PARKER & PARSLEY 91-A, L.P.                               9.87         7.38         7.38         6.31         6.04
PARKER & PARSLEY 91-B, L.P.                               9.33         7.18         6.88         5.72         5.96




---------------

(a) Gas production is converted to oil equivalents at the rate of six mcf per
barrel, representing the relative energy content of natural gas and oil.



                                      A-11
   113


                                    TABLE 11

                  PROVED RESERVES ATTRIBUTABLE TO PIONEER USA,
                NONMANAGING GENERAL PARTNERS AND LIMITED PARTNERS
                             AS OF DECEMBER 31, 2000






                                                                      TOTAL PROVED RESERVES
                                   ----------------------------------------------------------------------------------------------
                                                               NONMANAGING
                                        PIONEER USA (a)     GENERAL PARTNERS (b)     LIMITED PARTNERS (c)        TOTAL (D)
                                   ----------------------  ----------------------  ----------------------  ----------------------
                                      OIL &                  OIL &                   OIL &                   OIL &
                                   NGL (BBLS)   GAS (MCF)  NGL (BBLS)  GAS (MCF)   NGL (BBLS)  GAS (MCF)   NGL (BBLS)  GAS (MCF)
                                   ----------  ----------  ----------  ----------  ----------  ----------  ----------  ----------
                                                                                               
PARKER & PARSLEY 81-I, LTD.            57,816     116,841       4,224       8,535     149,140     301,399     211,180     426,775
PARKER & PARSLEY 81-II, LTD.           49,524      72,494       2,029       2,970     151,342     221,535     202,895     296,999
PARKER & PARSLEY 82-I, LTD.           114,245     257,041       4,026       9,058     239,586     539,046     357,857     805,145
PARKER & PARSLEY 82-II, LTD.          109,901     167,908       3,444       5,262     294,856     450,483     408,201     623,653
PARKER & PARSLEY 82-III, LTD.          88,780      85,126       2,916       2,796     219,396     210,367     311,092     298,289
PARKER & PARSLEY 83-A, LTD.           275,918     409,246      10,912      16,185     752,434   1,116,022   1,039,264   1,541,453
PARKER & PARSLEY 83-B, LTD.           340,686     554,365      13,365      21,748     918,850   1,495,154   1,272,901   2,071,267
PARKER & PARSLEY 84-A, LTD.           344,084     570,471      15,185      25,176     990,507   1,642,204   1,349,776   2,237,851
PARKER & PARSLEY 85-A, LTD.            11,187      15,154          --          --     371,156     502,769     382,343     517,923
PARKER & PARSLEY 85-B, LTD.             5,233       7,901          --          --     299,222     451,758     304,455     459,659
PARKER & PARSLEY PRIVATE
  INVESTMENT 85-A, LTD.                11,095      12,053          --          --     317,553     344,957     328,648     357,010
PARKER & PARSLEY SELECTED 85
  PRIVATE INVESTMENT                    6,238      10,351          --          --     225,761     374,615     231,999     384,966
PARKER & PARSLEY 86-A, LTD.             6,075      11,653          --          --     446,620     856,663     452,695     868,316
PARKER & PARSLEY 86-B, LTD.            16,246      21,064          --          --     919,385   1,192,033     935,631   1,213,097
PARKER & PARSLEY 86-C, LTD.            11,745      16,465          --          --     886,520   1,242,812     898,265   1,259,277
PARKER & PARSLEY PRIVATE
  INVESTMENT 86, LTD.                   3,174       4,960          --          --     314,198     491,002     317,372     495,962
PARKER & PARSLEY 87-A CONV., LTD.       3,451       5,510          --          --     178,340     284,684     181,791     290,194
PARKER & PARSLEY 87-A, LTD.            21,378      34,166          --          --   1,313,604   2,099,440   1,334,982   2,133,606
PARKER & PARSLEY 87-B CONV., LTD.       2,988       4,431          --          --     245,753     364,425     248,741     368,856
PARKER & PARSLEY 87-B, LTD.            12,411      18,405          --          --   1,003,438   1,487,986   1,015,849   1,506,391
PARKER & PARSLEY PRODUCING
  PROPERTIES 87-A, LTD.                 9,632       9,615          --          --     704,591     703,402     714,223     713,017
PARKER & PARSLEY PRODUCING
  PROPERTIES 87-B, LTD.                13,937      22,316          --          --     523,830     838,757     537,767     861,073
PARKER & PARSLEY PRIVATE
  INVESTMENT 87, LTD.                   7,631       9,691          --          --     755,457     959,391     763,088     969,082
PARKER & PARSLEY 88-A CONV., L.P.       5,253       7,315          --          --     222,619     310,018     227,872     317,333
PARKER & PARSLEY 88-A, L.P.            18,059      25,149          --          --     758,976   1,056,963     777,035   1,082,112
PARKER & PARSLEY 88-B CONV., L.P.       4,220       5,515          --          --     269,028     351,572     273,248     357,087
PARKER & PARSLEY 88-B, L.P.            13,722      17,933          --          --     659,140     861,434     672,862     879,367
PARKER & PARSLEY 88-C CONV., L.P.       2,870       4,039          --          --     219,589     308,985     222,459     313,024
PARKER & PARSLEY 88-C, L.P.             1,908       2,685          --          --     156,634     220,398     158,542     223,083
PARKER & PARSLEY PRODUCING
  PROPERTIES 88-A, L.P                  7,216       9,530          --          --     420,265     555,001     427,481     564,531
PARKER & PARSLEY PRIVATE
  INVESTMENT 88, L.P.                   7,708       9,375          --          --     763,081     928,143     770,789     937,518
PARKER & PARSLEY 89-A CONV., L.P.       2,027       2,852          --          --     200,631     282,306     202,658     285,158
PARKER & PARSLEY 89-A, L.P.            13,556      19,075          --          --     588,978     828,781     602,534     847,856
PARKER & PARSLEY 89-B CONV., L.P.       5,782       7,927          --          --     434,277     595,395     440,059     603,322
PARKER & PARSLEY 89-B, L.P.             9,810      13,454          --          --     474,439     650,677     484,249     664,131
PARKER & PARSLEY PRIVATE
  INVESTMENT 89, L.P.                   7,311       7,715          --          --     461,062     486,555     468,373     494,270
PARKER & PARSLEY 90-A CONV., L.P.       2,145       2,701          --          --     132,990     167,459     135,135     170,160
PARKER & PARSLEY 90-A, L.P.            12,362      15,527          --          --     381,738     479,494     394,100     495,021
PARKER & PARSLEY 90-B CONV., L.P.      12,549      16,252          --          --     740,794     959,455     753,343     975,707
PARKER & PARSLEY 90-B, L.P.            25,709      33,227          --          --   2,023,300   2,615,035   2,049,009   2,648,262
PARKER & PARSLEY 90-C CONV., L.P.       6,507       6,522          --          --     460,152     461,213     466,659     467,735
PARKER & PARSLEY 90-C, L.P.             9,158       9,179          --          --     741,036     742,738     750,194     751,917
PARKER & PARSLEY PRIVATE
  INVESTMENT 90, L.P.                  12,668      12,480          --          --     809,113     797,112     821,781     809,592
PARKER & PARSLEY 90
  SPRABERRY PRIVATE DEV., L.P           4,177       3,814          --          --     413,544     377,597     417,721     381,411
PARKER & PARSLEY 91-A, L.P.            13,541      19,696          --          --     965,302   1,404,059     978,843   1,423,755
PARKER & PARSLEY 91-B, L.P.            11,335      13,334          --          --   1,030,441   1,212,237   1,041,776   1,225,571
                                    ---------   ---------      ------      ------  ----------  ----------  ----------  ----------
                TOTAL (D)           1,732,968   2,702,523      56,101      91,730  25,548,668  34,823,531  27,337,737  37,617,784
                                    =========   =========      ======      ======  ==========  ==========  ==========  ==========




----------

(a)      Represents Pioneer USA's partnership interests in each partnership as:
         (1) the sole or managing general partner of the partnership; (2) a
         limited partner of the partnership; and (3) the sole general partner of
         each nonmanaging general partner. Pioneer USA will not receive any
         Pioneer common stock or cash payment for its partnership interests in
         any participating partnership. However, as a result of the merger of
         each participating partnership, Pioneer USA will acquire 100% of the
         properties of the partnership including properties attributable to its
         partnership interests in the partnerships.

(b)      Represents four unaffiliated individuals' partnership interests as
         limited partners of each nonmanaging general partner. Excludes Pioneer
         USA's partnership interests as general partner of each nonmanaging
         general partner.

(c)      Represents the partnership interests of unaffiliated limited partners
         of each partnership. Excludes Pioneer USA's partnership interests as a
         limited partner of any partnership.

(d)      Corresponds to amounts in the reserve report prepared by Williamson
         Petroleum Consultants, Inc. as of December 31, 2000.


                                      A-12
   114

                                    TABLE 12

           PARTNERSHIP ESTIMATED RESERVES ATTRIBUTABLE TO PIONEER USA,
                NONMANAGING GENERAL PARTNERS AND LIMITED PARTNERS
                              AS OF MARCH 31, 2001






                                                                 TOTAL PARTNERSHIP ESTIMATED RESERVES
                                                       ---------------------------------------------------
                                                                                     NON MANAGING
                                                            PIONEER USA (a)       GENERAL PARTNERS (b)
                                                       -----------------------   -----------------------
                                                         OIL &                     OIL &
                                                       NGL (BBLS)   GAS (MCF)    NGL (BBLS)   GAS (MCF)
                                                       ----------   ----------   ----------   ----------
                                                                                  
PARKER & PARSLEY 81-I, LTD.                                44,015       89,859        3,183        6,506
PARKER & PARSLEY 81-II, LTD.                               34,163       51,620        1,399        2,115
PARKER & PARSLEY 82-I, LTD.                                82,220      182,248        2,887        6,397
PARKER & PARSLEY 82-II, LTD.                               83,829      124,152        2,621        3,875
PARKER & PARSLEY 82-III, LTD.                              70,421       67,391        2,308        2,201
PARKER & PARSLEY 83-A, LTD.                               214,832      320,743        8,496       12,685
PARKER & PARSLEY 83-B, LTD.                               275,618      448,098       10,813       17,579
PARKER & PARSLEY 84-A, LTD.                               285,567      482,485       12,603       21,293
PARKER & PARSLEY 85-A, LTD.                                 8,498       11,656           --           --
PARKER & PARSLEY 85-B, LTD.                                 3,895        5,745           --           --
PARKER & PARSLEY PRIVATE INVESTMENT 85-A, LTD.              9,600       10,166           --           --
PARKER & PARSLEY SELECTED 85 PRIVATE INVESTMENT, LTD.       5,008        8,464           --           --
PARKER & PARSLEY 86-A, LTD.                                 4,687        8,889           --           --
PARKER & PARSLEY 86-B, LTD.                                13,080       17,075           --           --
PARKER & PARSLEY 86-C, LTD.                                 8,652       11,999           --           --
PARKER & PARSLEY PRIVATE INVESTMENT 86, LTD.                2,479        3,864           --           --
PARKER & PARSLEY 87-A CONV., LTD.                           2,683        4,348           --           --
PARKER & PARSLEY 87-A, LTD.                                16,718       27,103           --           --
PARKER & PARSLEY 87-B CONV., LTD.                           2,359        3,531           --           --
PARKER & PARSLEY 87-B, LTD.                                 9,798       14,667           --           --
PARKER & PARSLEY PRODUCING PROPERTIES 87-A, LTD.            7,415        7,413           --           --
PARKER & PARSLEY PRODUCING PROPERTIES 87-B, LTD.           11,686       18,860           --           --
PARKER & PARSLEY PRIVATE INVESTMENT 87, LTD.                6,337        8,010           --           --
PARKER & PARSLEY 88-A CONV., L.P.                           4,229        5,872           --           --
PARKER & PARSLEY 88-A, L.P.                                14,541       20,192           --           --
PARKER & PARSLEY 88-B CONV., L.P.                           3,480        4,558           --           --
PARKER & PARSLEY 88-B, L.P.                                11,314       14,819           --           --
PARKER & PARSLEY 88-C CONV., L.P.                           2,345        3,297           --           --
PARKER & PARSLEY 88-C, L.P.                                 1,559        2,192           --           --
PARKER & PARSLEY PRODUCING PROPERTIES 88-A, L.P.            6,055        7,923           --           --
PARKER & PARSLEY PRIVATE INVESTMENT 88, L.P.                6,543        7,829           --           --
PARKER & PARSLEY 89-A CONV., L.P.                           1,698        2,414           --           --
PARKER & PARSLEY 89-A, L.P.                                11,359       16,152           --           --
PARKER & PARSLEY 89-B CONV., L.P.                           4,604        6,368           --           --
PARKER & PARSLEY 89-B, L.P.                                 7,808       10,804           --           --
PARKER & PARSLEY PRIVATE INVESTMENT 89, L.P.                5,909        6,237           --           --
PARKER & PARSLEY 90-A CONV., L.P.                           1,744        2,199           --           --
PARKER & PARSLEY 90-A, L.P.                                 9,949       12,544           --           --
PARKER & PARSLEY 90-B CONV., L.P.                          10,224       13,186           --           --
PARKER & PARSLEY 90-B, L.P.                                20,923       26,947           --           --
PARKER & PARSLEY 90-C CONV., L.P.                           5,218        5,187           --           --
PARKER & PARSLEY 90-C, L.P.                                 7,344        7,301           --           --
PARKER & PARSLEY PRIVATE INVESTMENT 90, L.P.               10,449       10,006           --           --
PARKER & PARSLEY 90 SPRABERRY PRIVATE DEV., L.P.            3,482        3,172           --           --
PARKER & PARSLEY 91-A, L.P.                                11,647       16,716           --           --
PARKER & PARSLEY 91-B, L.P.                                 9,825       11,641           --           --
                                                       ----------   ----------   ----------   ----------
                  TOTAL                                 1,375,809    2,145,942       44,310       72,651
                                                       ==========   ==========   ==========   ==========



                                                                TOTAL PARTNERSHIP ESTIMATED RESERVES
                                                          -------------------------------------------------
                                                           LIMITED PARTNERS (c)             TOTAL
                                                          -----------------------   -----------------------
                                                            OIL &                    OIL &
                                                          NGL (BBLS)   GAS (MCF)    NGL (BBLS)    GAS (MCF)
                                                          ----------   ----------   ----------   ----------
                                                                                     
PARKER & PARSLEY 81-I, LTD.                                  119,464      242,599      166,662      338,964
PARKER & PARSLEY 81-II, LTD.                                 106,202      158,535      141,764      212,270
PARKER & PARSLEY 82-I, LTD.                                  174,292      386,652      259,399      575,297
PARKER & PARSLEY 82-II, LTD.                                 229,733      344,629      316,183      472,656
PARKER & PARSLEY 82-III, LTD.                                176,244      171,833      248,973      241,425
PARKER & PARSLEY 83-A, LTD.                                  585,852      874,674      809,180    1,208,102
PARKER & PARSLEY 83-B, LTD.                                  743,358    1,208,548    1,029,789    1,674,225
PARKER & PARSLEY 84-A, LTD.                                  822,057    1,388,920    1,120,227    1,892,698
PARKER & PARSLEY 85-A, LTD.                                  281,965      386,713      290,463      398,369
PARKER & PARSLEY 85-B, LTD.                                  222,731      328,479      226,626      334,224
PARKER & PARSLEY PRIVATE INVESTMENT 85-A, LTD.               274,765      290,970      284,365      301,136
PARKER & PARSLEY SELECTED 85 PRIVATE INVESTMENT, LTD.        181,256      306,332      186,264      314,796
PARKER & PARSLEY 86-A, LTD.                                  344,581      653,460      349,268      662,349
PARKER & PARSLEY 86-B, LTD.                                  740,201      966,261      753,281      983,336
PARKER & PARSLEY 86-C, LTD.                                  653,081      905,703      661,733      917,702
PARKER & PARSLEY PRIVATE INVESTMENT 86, LTD.                 245,444      382,576      247,923      386,440
PARKER & PARSLEY 87-A CONV., LTD.                            138,639      224,665      141,322      229,013
PARKER & PARSLEY 87-A, LTD.                                1,027,295    1,665,437    1,044,013    1,692,540
PARKER & PARSLEY 87-B CONV., LTD.                            193,991      290,404      196,350      293,935
PARKER & PARSLEY 87-B, LTD.                                  792,129    1,185,806      801,927    1,200,473
PARKER & PARSLEY PRODUCING PROPERTIES 87-A, LTD.             542,443      542,313      549,858      549,726
PARKER & PARSLEY PRODUCING PROPERTIES 87-B, LTD.             439,208      708,847      450,894      727,707
PARKER & PARSLEY PRIVATE INVESTMENT 87, LTD.                 627,335      792,961      633,672      800,971
PARKER & PARSLEY 88-A CONV., L.P.                            179,233      248,890      183,462      254,762
PARKER & PARSLEY 88-A, L.P.                                  611,107      848,608      625,648      868,800
PARKER & PARSLEY 88-B CONV., L.P.                            221,815      290,537      225,295      295,095
PARKER & PARSLEY 88-B, L.P.                                  543,481      711,836      554,795      726,655
PARKER & PARSLEY 88-C CONV., L.P.                            179,408      252,233      181,753      255,530
PARKER & PARSLEY 88-C, L.P.                                  127,978      179,932      129,537      182,124
PARKER & PARSLEY PRODUCING PROPERTIES 88-A, L.P.             352,641      461,401      358,696      469,324
PARKER & PARSLEY PRIVATE INVESTMENT 88, L.P.                 647,747      775,098      654,290      782,927
PARKER & PARSLEY 89-A CONV., L.P.                            168,085      239,019      169,783      241,433
PARKER & PARSLEY 89-A, L.P.                                  493,498      701,759      504,857      717,911
PARKER & PARSLEY 89-B CONV., L.P.                            345,765      478,251      350,369      484,619
PARKER & PARSLEY 89-B, L.P.                                  377,628      522,545      385,436      533,349
PARKER & PARSLEY PRIVATE INVESTMENT 89, L.P.                 372,674      393,332      378,583      399,569
PARKER & PARSLEY 90-A CONV., L.P.                            108,108      136,309      109,852      138,508
PARKER & PARSLEY 90-A, L.P.                                  307,219      387,363      317,168      399,907
PARKER & PARSLEY 90-B CONV., L.P.                            603,559      778,404      613,783      791,590
PARKER & PARSLEY 90-B, L.P.                                1,646,642    2,120,743    1,667,565    2,147,690
PARKER & PARSLEY 90-C CONV., L.P.                            369,034      366,832      374,252      372,019
PARKER & PARSLEY 90-C, L.P.                                  594,276      590,739      601,620      598,040
PARKER & PARSLEY PRIVATE INVESTMENT 90, L.P.                 667,438      639,137      677,887      649,143
PARKER & PARSLEY 90 SPRABERRY PRIVATE DEV., L.P.             344,669      314,060      348,151      317,232
PARKER & PARSLEY 91-A, L.P.                                  830,236    1,191,626      841,883    1,208,342
PARKER & PARSLEY 91-B, L.P.                                  893,203    1,058,325      903,028    1,069,966
                                                          ----------   ----------   ----------   ----------
                  TOTAL                                   20,647,710   28,094,296   22,067,829   30,312,889
                                                          ==========   ==========   ==========   ==========




----------


(a)  Represents Pioneer USA's partnership interests in each partnership as: (1)
     the sole or managing general partner of the partnership; (2) a limited
     partner of the partnership; and (3) the sole general partner of each
     nonmanaging general partner. Pioneer USA will not receive any Pioneer
     common stock or cash payment for its partnership interests in any
     participating partnership. However, as a result of the merger of each
     participating partnership, Pioneer USA will acquire 100% of the properties
     of the partnership including properties attributable to its partnership
     interests in the partnerships.

(b)  Represents four unaffiliated individuals' partnership interests as limited
     partners of each nonmanaging general partner. Excludes Pioneer USA's
     partnership interests as general partner of each nonmanaging general
     partner.

(c)  Represents the partnership interests of unaffiliated limited partners of
     each partnership. Excludes Pioneer USA's partnership interests as a limited
     partner of any partnership.





                                      A-13
   115



                                    TABLE 13

                   OIL, NATURAL GAS LIQUIDS AND GAS PRODUCTION
                  FOR THE THREE MONTHS ENDED MARCH 31, 2001 AND
           2000 AND THE YEARS ENDED DECEMBER 31, 2000, 1999 AND 1998





                                                                           OIL & NGL (BBLS)
                                                        --------------------------------------------------------------
                                                          FOR THE THREE MONTHS            FOR THE YEAR ENDED
                                                            ENDED MARCH 31,                   DECEMBER 31,
                                                        -----------------------   ------------------------------------
                                                           2001         2000         2000        1999          1998
                                                        ----------   ----------   ----------   ----------   ----------
                                                                                            
PARKER & PARSLEY 81-I, LTD.                                  2,927        3,619       13,976       14,970       13,937
PARKER & PARSLEY 81-II, LTD.                                 2,704        2,737       13,921       13,232       16,033
PARKER & PARSLEY 82-I, LTD.                                  5,318        6,243       24,158       23,886       25,898
PARKER & PARSLEY 82-II, LTD.                                 5,618        6,483       24,922       27,554       27,854
PARKER & PARSLEY 82-III, LTD.                                4,200        5,615       20,646       20,801       19,540
PARKER & PARSLEY 83-A, LTD.                                 13,844       16,424       66,679       69,238       67,612
PARKER & PARSLEY 83-B, LTD.                                 15,777       21,782       81,814       89,446       93,695
PARKER & PARSLEY 84-A, LTD.                                 20,020       21,791       85,485       85,868       88,702
PARKER & PARSLEY 85-A, LTD.                                  6,052        7,435       27,458       31,246       27,808
PARKER & PARSLEY 85-B, LTD.                                  4,994        4,993       20,809       21,410       24,803
PARKER & PARSLEY PRIVATE INVESTMENT 85-A, LTD.               3,847        4,692       17,619       20,664       21,200
PARKER & PARSLEY SELECTED 85 PRIVATE INVESTMENT, LTD.        3,732        3,625       15,698       14,598       15,439
PARKER & PARSLEY 86-A, LTD.                                  6,352        7,966       31,785       33,226       31,472
PARKER & PARSLEY 86-B, LTD.                                 11,736       15,880       62,337       63,132       70,399
PARKER & PARSLEY 86-C, LTD.                                 15,075       16,610       66,329       64,894       74,674
PARKER & PARSLEY PRIVATE INVESTMENT 86, LTD.                 4,163        5,424       20,938       20,843       22,245
PARKER & PARSLEY 87-A CONV., LTD.                            2,932        3,368       13,096       13,578       14,371
PARKER & PARSLEY 87-A, LTD.                                 21,902       25,185       97,824      101,441      107,375
PARKER & PARSLEY 87-B CONV., LTD.                            3,167        4,280       16,015       16,758       17,879
PARKER & PARSLEY 87-B, LTD.                                 12,941       17,478       65,401       68,433       73,036
PARKER & PARSLEY PRODUCING PROPERTIES 87-A, LTD.            12,860       13,873       53,656       53,101       64,367
PARKER & PARSLEY PRODUCING PROPERTIES 87-B, LTD.             7,142       10,018       33,115       35,770       40,796
PARKER & PARSLEY PRIVATE INVESTMENT 87, LTD.                 8,886        9,329       35,242       40,495       42,801
PARKER & PARSLEY 88-A CONV., L.P.                            3,883        3,496       14,604       17,052       16,899
PARKER & PARSLEY 88-A, L.P.                                 13,238       11,946       49,808       58,141       57,635
PARKER & PARSLEY 88-B CONV., L.P.                            3,683        4,667       18,572       16,986       17,610
PARKER & PARSLEY 88-B, L.P.                                  9,068       11,503       45,729       41,830       43,365
PARKER & PARSLEY 88-C CONV., L.P.                            3,111        3,815       15,453       14,136       14,859
PARKER & PARSLEY 88-C, L.P.                                  2,211        2,729       11,023       10,071       10,596
PARKER & PARSLEY PRODUCING PROPERTIES 88-A, L.P.             6,273        6,060       26,976       30,280       34,491
PARKER & PARSLEY PRIVATE INVESTMENT 88, L.P.                 9,637       10,892       46,284       48,802       48,933
PARKER & PARSLEY 89-A CONV., L.P.                            3,016        3,150       13,092       14,166       14,102
PARKER & PARSLEY 89-A, L.P.                                  8,974        9,366       38,923       42,129       41,931
PARKER & PARSLEY 89-B CONV., L.P.                            6,485        7,859       30,959       32,585       35,481
PARKER & PARSLEY 89-B, L.P.                                  7,140        8,656       34,089       35,879       39,063
PARKER & PARSLEY PRIVATE INVESTMENT 89, L.P.                 7,528        7,721       30,738       30,310       36,741
PARKER & PARSLEY 90-A CONV., L.P.                            2,168        2,527        9,876       10,130       11,399
PARKER & PARSLEY 90-A, L.P.                                  6,265        7,290       28,519       29,248       32,915
PARKER & PARSLEY 90-B CONV., L.P.                           11,994       12,969       53,388       53,864       58,543
PARKER & PARSLEY 90-B, L.P.                                 32,546       35,197      144,804      146,064      158,775
PARKER & PARSLEY 90-C CONV., L.P.                            6,670        7,745       32,773       32,618       33,187
PARKER & PARSLEY 90-C, L.P.                                 10,718       12,449       52,686       52,433       53,358
PARKER & PARSLEY PRIVATE INVESTMENT 90, L.P.                11,435       13,108       52,913       46,335       49,468
PARKER & PARSLEY 90 SPRABERRY PRIVATE DEV., L.P.             5,193        5,215       22,593       20,688       20,835
PARKER & PARSLEY 91-A, L.P.                                 13,120       16,199       64,129       64,820       70,623
PARKER & PARSLEY 91-B, L.P.                                 11,599       17,038       69,550       65,056       66,527
                                                        ----------    ---------  -----------   ----------   ----------
                  TOTAL                                    392,144      456,447    1,816,404    1,858,207    1,969,272
                                                        ==========    =========  ===========   ==========   ==========


                                                                               GAS (MCF)
                                                       -------------------------------------------------------------
                                                       FOR THE THREE MONTHS              FOR THE YEAR ENDED
                                                          ENDED MARCH 31,                   DECEMBER 31,
                                                       ----------------------   ------------------------------------
                                                         2001         2000          2000        1999          1998
                                                       ---------   ----------   ----------   ----------   ----------
                                                                                           
PARKER & PARSLEY 81-I, LTD.                                5,562        6,102       25,901       28,708       24,638
PARKER & PARSLEY 81-II, LTD.                               5,731        1,489       15,864       19,167       22,439
PARKER & PARSLEY 82-I, LTD.                               13,274       12,235       45,981       48,380       48,971
PARKER & PARSLEY 82-II, LTD.                              11,592        9,151       35,900       42,858       41,862
PARKER & PARSLEY 82-III, LTD.                              5,196        6,304       21,480       23,061       17,680
PARKER & PARSLEY 83-A, LTD.                               25,707       22,988       94,612      109,716       95,156
PARKER & PARSLEY 83-B, LTD.                               29,602       35,379      132,106      157,842      147,495
PARKER & PARSLEY 84-A, LTD.                               33,550       35,071      138,617      154,235      145,870
PARKER & PARSLEY 85-A, LTD.                               12,365       11,812       41,549       55,226       43,021
PARKER & PARSLEY 85-B, LTD.                                8,365        7,429       30,909       33,467       41,501
PARKER & PARSLEY PRIVATE INVESTMENT 85-A, LTD.             4,506        5,061       20,905       23,218       22,343
PARKER & PARSLEY SELECTED 85 PRIVATE INVESTMENT, LTD.      6,584        5,393       22,987       27,627       25,328
PARKER & PARSLEY 86-A, LTD.                               10,876       14,461       56,549       62,354       49,805
PARKER & PARSLEY 86-B, LTD.                               20,049       20,435       79,859       86,726       97,715
PARKER & PARSLEY 86-C, LTD.                               28,858       21,750       95,610      105,081      129,149
PARKER & PARSLEY PRIVATE INVESTMENT 86, LTD.               8,951        7,936       33,570       30,923       33,219
PARKER & PARSLEY 87-A CONV., LTD.                          5,718        5,425       20,355       24,503       24,025
PARKER & PARSLEY 87-A, LTD.                               42,755       40,626      152,075      183,099      179,494
PARKER & PARSLEY 87-B CONV., LTD.                          4,549        6,437       23,682       24,436       25,477
PARKER & PARSLEY 87-B, LTD.                               18,570       26,331       96,740       99,771      104,072
PARKER & PARSLEY PRODUCING PROPERTIES 87-A, LTD.          11,750        9,135       45,872       53,145       56,240
PARKER & PARSLEY PRODUCING PROPERTIES 87-B, LTD.           9,834       14,555       49,380       48,774       50,220
PARKER & PARSLEY PRIVATE INVESTMENT 87, LTD.              11,385       11,546       48,307       52,874       58,036
PARKER & PARSLEY 88-A CONV., L.P.                          8,645        4,685       21,399       27,417       25,367
PARKER & PARSLEY 88-A, L.P.                               29,495       15,987       72,965       93,498       86,501
PARKER & PARSLEY 88-B CONV., L.P.                          3,500        5,699       21,781       23,221       21,214
PARKER & PARSLEY 88-B, L.P.                                8,631       14,019       53,620       57,190       52,254
PARKER & PARSLEY 88-C CONV., L.P.                          3,530        4,769       19,618       21,119       19,764
PARKER & PARSLEY 88-C, L.P.                                2,517        3,392       13,979       15,049       14,091
PARKER & PARSLEY PRODUCING PROPERTIES 88-A, L.P.           8,730        9,789       37,939       44,467       51,099
PARKER & PARSLEY PRIVATE INVESTMENT 88, L.P.              14,638       15,649       59,532       66,701       61,718
PARKER & PARSLEY 89-A CONV., L.P.                          5,605        4,757       20,057       20,484       21,106
PARKER & PARSLEY 89-A, L.P.                               16,665       14,142       59,638       60,905       62,751
PARKER & PARSLEY 89-B CONV., L.P.                         12,480       11,218       42,179       46,681       52,345
PARKER & PARSLEY 89-B, L.P.                               13,738       12,352       46,454       51,400       57,643
PARKER & PARSLEY PRIVATE INVESTMENT 89, L.P.              11,008        6,473       30,037       32,985       44,624
PARKER & PARSLEY 90-A CONV., L.P.                          4,098        3,430       13,365       14,989       16,309
PARKER & PARSLEY 90-A, L.P.                               11,838        9,897       38,570       43,302       47,086
PARKER & PARSLEY 90-B CONV., L.P.                         18,996       15,621       64,786       70,803       73,460
PARKER & PARSLEY 90-B, L.P.                               51,504       42,382      175,696      192,016      199,215
PARKER & PARSLEY 90-C CONV., L.P.                          8,151        6,434       30,423       29,399       30,348
PARKER & PARSLEY 90-C, L.P.                               13,106       10,341       48,907       47,265       48,787
PARKER & PARSLEY PRIVATE INVESTMENT 90, L.P.              14,913       12,754       49,484       47,331       54,218
PARKER & PARSLEY 90 SPRABERRY PRIVATE DEV., L.P.           8,177        3,949       22,121       19,579       24,095
PARKER & PARSLEY 91-A, L.P.                               19,051       22,979       94,315      100,615      108,617
PARKER & PARSLEY 91-B, L.P.                               10,623       19,802       85,556       74,025       68,244
                                                      ----------    ---------  -----------   ----------   ----------
                  TOTAL                                  634,968      607,571    2,451,231    2,695,632    2,724,612
                                                      ==========    =========  ===========   ==========   ==========



                                                                             TOTAL (BOE) (A)
                                                      --------------------------------------------------------------
                                                        FOR THE THREE MONTHS            FOR THE YEAR ENDED
                                                          ENDED MARCH 31,                 DECEMBER 31,
                                                      -----------------------   ------------------------------------
                                                         2001         2000         2000         1999         1998
                                                      ----------   ----------   ----------   ----------   ----------
                                                                                          
PARKER & PARSLEY 81-I, LTD.                                3,854        4,636       18,293       19,755       18,043
PARKER & PARSLEY 81-II, LTD.                               3,659        2,985       16,565       16,427       19,773
PARKER & PARSLEY 82-I, LTD.                                7,530        8,282       31,822       31,949       34,060
PARKER & PARSLEY 82-II, LTD.                               7,550        8,008       30,905       34,697       34,831
PARKER & PARSLEY 82-III, LTD.                              5,066        6,666       24,226       24,645       22,487
PARKER & PARSLEY 83-A, LTD.                               18,129       20,255       82,448       87,524       83,471
PARKER & PARSLEY 83-B, LTD.                               20,711       27,679      103,832      115,753      118,278
PARKER & PARSLEY 84-A, LTD.                               25,612       27,636      108,588      111,574      113,014
PARKER & PARSLEY 85-A, LTD.                                8,113        9,404       34,383       40,450       34,978
PARKER & PARSLEY 85-B, LTD.                                6,388        6,231       25,961       26,988       31,720
PARKER & PARSLEY PRIVATE INVESTMENT 85-A, LTD.             4,598        5,536       21,103       24,534       24,924
PARKER & PARSLEY SELECTED 85 PRIVATE INVESTMENT, LTD.      4,829        4,524       19,529       19,203       19,660
PARKER & PARSLEY 86-A, LTD.                                8,165       10,376       41,210       43,618       39,773
PARKER & PARSLEY 86-B, LTD.                               15,078       19,286       75,647       77,586       86,685
PARKER & PARSLEY 86-C, LTD.                               19,885       20,235       82,264       82,408       96,199
PARKER & PARSLEY PRIVATE INVESTMENT 86, LTD.               5,655        6,747       26,533       25,997       27,782
PARKER & PARSLEY 87-A CONV., LTD.                          3,885        4,272       16,489       17,662       18,375
PARKER & PARSLEY 87-A, LTD.                               29,028       31,956      123,170      131,958      137,291
PARKER & PARSLEY 87-B CONV., LTD.                          3,925        5,353       19,962       20,831       22,125
PARKER & PARSLEY 87-B, LTD.                               16,036       21,867       81,524       85,062       90,381
PARKER & PARSLEY PRODUCING PROPERTIES 87-A, LTD.          14,818       15,396       61,301       61,959       73,740
PARKER & PARSLEY PRODUCING PROPERTIES 87-B, LTD.           8,781       12,444       41,345       43,899       49,166
PARKER & PARSLEY PRIVATE INVESTMENT 87, LTD.              10,784       11,253       43,293       49,307       52,474
PARKER & PARSLEY 88-A CONV., L.P.                          5,324        4,277       18,171       21,622       21,127
PARKER & PARSLEY 88-A, L.P.                               18,154       14,611       61,969       73,724       72,052
PARKER & PARSLEY 88-B CONV., L.P.                          4,266        5,617       22,202       20,856       21,146
PARKER & PARSLEY 88-B, L.P.                               10,507       13,840       54,666       51,362       52,074
PARKER & PARSLEY 88-C CONV., L.P.                          3,699        4,610       18,723       17,656       18,153
PARKER & PARSLEY 88-C, L.P.                                2,631        3,294       13,353       12,579       12,945
PARKER & PARSLEY PRODUCING PROPERTIES 88-A, L.P.           7,728        7,692       33,299       37,691       43,008
PARKER & PARSLEY PRIVATE INVESTMENT 88, L.P.              12,077       13,500       56,206       59,919       59,219
PARKER & PARSLEY 89-A CONV., L.P.                          3,950        3,943       16,435       17,580       17,620
PARKER & PARSLEY 89-A, L.P.                               11,752       11,723       48,863       52,280       52,390
PARKER & PARSLEY 89-B CONV., L.P.                          8,565        9,729       37,989       40,365       44,205
PARKER & PARSLEY 89-B, L.P.                                9,430       10,715       41,831       44,446       48,670
PARKER & PARSLEY PRIVATE INVESTMENT 89, L.P.               9,363        8,800       35,744       35,808       44,178
PARKER & PARSLEY 90-A CONV., L.P.                          2,851        3,099       12,104       12,628       14,117
PARKER & PARSLEY 90-A, L.P.                                8,238        8,940       34,947       36,465       40,763
PARKER & PARSLEY 90-B CONV., L.P.                         15,160       15,573       64,186       65,665       70,786
PARKER & PARSLEY 90-B, L.P.                               41,130       42,261      174,087      178,067      191,978
PARKER & PARSLEY 90-C CONV., L.P.                          8,029        8,817       37,844       37,518       38,245
PARKER & PARSLEY 90-C, L.P.                               12,902       14,173       60,837       60,311       61,489
PARKER & PARSLEY PRIVATE INVESTMENT 90, L.P.              13,921       15,234       61,160       54,224       58,504
PARKER & PARSLEY 90 SPRABERRY PRIVATE DEV., L.P.           6,556        5,873       26,280       23,951       24,851
PARKER & PARSLEY 91-A, L.P.                               16,295       20,029       79,848       81,589       88,726
PARKER & PARSLEY 91-B, L.P.                               13,370       20,338       83,809       77,394       77,901
                                                      ----------    ---------  -----------   ----------   ----------
                  TOTAL                                  497,977      557,715    2,224,946    2,307,486    2,423,377
                                                      ==========    =========  ===========   ==========   ==========





----------

(a) Gas production is converted to oil equivalents at the rate of six mcf per
barrel, representing the relative energy content of natural gas and oil.




                                      A-14
   116



                                    TABLE 14

                     PRODUCTIVE WELLS AND DEVELOPED ACREAGE
                              AS OF MARCH 31, 2001






                                                               PRODUCTIVE OIL AND
                                                                    GAS WELLS                  DEVELOPED ACRES
                                                            -------------------------     -------------------------
                                                             GROSS (a)       NET (b)      GROSS (a)       NET (b)
                                                            ----------     ----------     ----------     ----------
                                                                                             
PARKER & PARSLEY 81-I, LTD.                                         16           9.13          2,328          1,250
PARKER & PARSLEY 81-II, LTD.                                        12           8.40          1,563          1,050
PARKER & PARSLEY 82-I, LTD.                                         17          16.19          1,702          1,557
PARKER & PARSLEY 82-II, LTD.                                        16          15.38          1,882          1,489
PARKER & PARSLEY 82-III, LTD.                                       13          11.63          2,013          1,381
PARKER & PARSLEY 83-A, LTD.                                         42          36.59          5,154          3,602
PARKER & PARSLEY 83-B, LTD.                                         41          40.66          5,227          4,190
PARKER & PARSLEY 84-A, LTD.                                         38          37.55          4,929          4,019
PARKER & PARSLEY 85-A, LTD.                                         21          17.05          2,083          1,315
PARKER & PARSLEY 85-B, LTD.                                         17          13.05          2,536          1,215
PARKER & PARSLEY PRIVATE INVESTMENT 85-A, LTD.                      11           7.78          1,204            658
PARKER & PARSLEY SELECTED 85 PRIVATE INVESTMENT, LTD.               12           9.23          1,282            738
PARKER & PARSLEY 86-A, LTD.                                         26          21.86          1,689          1,108
PARKER & PARSLEY 86-B, LTD.                                         43          35.65          2,709          1,694
PARKER & PARSLEY 86-C, LTD.                                         53          44.36          4,432          2,786
PARKER & PARSLEY PRIVATE INVESTMENT 86, LTD.                        14          12.37          1,685          1,131
PARKER & PARSLEY 87-A CONV., LTD.                                   73           7.06          6,498            659
PARKER & PARSLEY 87-A, LTD.                                         73          52.76          6,498          4,926
PARKER & PARSLEY 87-B CONV., LTD.                                   48           8.13          4,465            796
PARKER & PARSLEY 87-B, LTD.                                         48          33.21          4,465          3,251
PARKER & PARSLEY PRODUCING PROPERTIES 87-A, LTD.                    84          39.42         10,576          3,615
PARKER & PARSLEY PRODUCING PROPERTIES 87-B, LTD.                    34          20.52          4,302          1,609
PARKER & PARSLEY PRIVATE INVESTMENT 87, LTD.                        24          19.65          1,685          1,130
PARKER & PARSLEY 88-A CONV., L.P.                                   39           8.01          3,286            592
PARKER & PARSLEY 88-A, L.P.                                         39          25.98          3,286          1,628
PARKER & PARSLEY 88-B CONV., L.P.                                   41           7.65          2,766            956
PARKER & PARSLEY 88-B, L.P.                                         41          18.82          2,766            412
PARKER & PARSLEY 88-C CONV., L.P.                                   41           6.97          2,757            343
PARKER & PARSLEY 88-C, L.P.                                         41           4.97          2,757            244
PARKER & PARSLEY PRODUCING PROPERTIES 88-A, L.P.                    23          18.69          1,689          1,193
PARKER & PARSLEY PRIVATE INVESTMENT 88, L.P.                        22          19.18          1,873          1,211
PARKER & PARSLEY 89-A CONV., L.P.                                   31           5.73          2,811            553
PARKER & PARSLEY 89-A, L.P.                                         31          17.04          2,811          1,645
PARKER & PARSLEY 89-B CONV., L.P.                                   33          13.72          2,992          1,150
PARKER & PARSLEY 89-B, L.P.                                         33          15.12          2,992          1,267
PARKER & PARSLEY PRIVATE INVESTMENT 89, L.P.                        19          13.87          1,913          1,253
PARKER & PARSLEY 90-A CONV., L.P.                                   25           4.56          2,045            395
PARKER & PARSLEY 90-A, L.P.                                         25          13.17          2,045          1,141
PARKER & PARSLEY 90-B CONV., L.P.                                  103          23.18          9,729          2,086
PARKER & PARSLEY 90-B, L.P.                                        103          62.92          9,729          5,658
PARKER & PARSLEY 90-C CONV., L.P.                                   42          13.68          1,021            316
PARKER & PARSLEY 90-C, L.P.                                         42          21.99          1,021            509
PARKER & PARSLEY PRIVATE INVESTMENT 90, L.P.                        27          20.65          2,333          1,556
PARKER & PARSLEY 90 SPRABERRY PRIVATE DEV., L.P.                    12           9.00          1,017            658
PARKER & PARSLEY 91-A, L.P.                                         47          24.71          4,389          1,891
PARKER & PARSLEY 91-B, L.P.                                         29          21.97          1,922          1,301
                                                              --------       --------       --------       --------
                               TOTAL                             1,665         909.21        150,857         73,127
                                                              ========       ========       ========       ========




----------

(a)      A "gross well" or "gross acre" is a well or an acre in which a working
         interest is owned. The number of gross wells or acres represents the
         sum of the wells or acres in which a working interest is owned.

(b)      A "net well" or "net acre" is deemed to exist when the sum of the
         fractional working interests in gross wells or acres equals one. The
         number of net wells or acres is the sum of the fractional working
         interests in gross wells or acres.





                                      A-15
   117



                                    TABLE 15

                   RECENT TRADES OF PARTNERSHIP INTERESTS (a)
                              PER $1,000 INVESTMENT
                  FOR THE THREE MONTHS ENDED MARCH 31, 2001 AND
                   THE YEARS ENDED DECEMBER 31, 2000 AND 1999







                                                                   PER $1,000 INVESTMENT
                                                   ------------------------------------------------------
                                                         FOR THE THREE MONTHS ENDED MARCH 31, 2001
                                                   -----------------------------------------------------
                                                           SALES PRICE
                                                   -------------------------     NUMBER         NUMBER
                                                      HIGH           LOW        OF SALES        SOLD
                                                   -----------   -----------   -----------   -----------
                                                                                 
PARKER & PARSLEY 82-1, LTD.                        $        --   $        --            --            --
PARKER & PARSLEY 82-11, LTD.                             75.00         75.00             2            20
PARKER & PARSLEY 83-A, LTD.                             120.00        110.00             3            55
PARKER & PARSLEY 83-B, LTD.                             137.00        117.50             2            20
PARKER & PARSLEY 84-A, LTD.                             152.00        143.56             3            70
PARKER & PARSLEY 85-A, LTD.                                 --            --            --            --
PARKER & PARSLEY 85-B, LTD.                             145.00        145.00             1            10
PARKER & PARSLEY 86-A, LTD.                             140.00        140.00             1            10
PARKER & PARSLEY 86-B, LTD.                             165.00        165.00             1             5
PARKER & PARSLEY 86-C, LTD.                             147.66        130.00             2            15
PARKER & PARSLEY 87-A, LTD.                             163.75        145.00             3           155
PARKER & PARSLEY 87-B, LTD.                             157.20        157.20             1             5
PARKER & PARSLEY PRODUCING PROPERTIES 87-A, LTD.        280.00        280.00             1            20
PARKER & PARSLEY PRODUCING PROPERTIES 87-B, LTD.        138.00        138.00             1             4
PARKER & PARSLEY 88-A, L.P.                             210.00        186.00             3            35
PARKER & PARSLEY 88-B, L.P.                                 --            --            --            --
PARKER & PARSLEY 88-C, L.P.                             250.00        250.00             2            90
PARKER & PARSLEY PRODUCING PROPERTIES 88-A, L.P.            --            --            --            --
PARKER & PARSLEY 89-A, L.P.                             215.00        215.00             2            30
PARKER & PARSLEY 89-B, L.P.                                 --            --            --            --
PARKER & PARSLEY 90-A, L.P.                                 --            --            --            --
PARKER & PARSLEY 90-B, L.P.                             260.00        211.12             4            50
PARKER & PARSLEY 90-C, L.P.                             225.00        112.30             2            35
PARKER & PARSLEY 91-A, L.P.                             275.00        275.00             1            10
PARKER & PARSLEY 91-B, L.P.                                 --            --            --            --



                                                                 PER $1,000 INVESTMENT
                                                  -------------------------------------------------------
                                                           FOR THE YEAR ENDED DECEMBER 31, 2000
                                                  -----------------------------------------------------
                                                        SALES PRICE
                                                  -------------------------    NUMBER         NUMBER
                                                     HIGH          LOW         OF SALES        SOLD
                                                  -----------   -----------   -----------   -----------
                                                                                
PARKER & PARSLEY 82-1, LTD.                       $     47.75   $     37.50             5            61
PARKER & PARSLEY 82-11, LTD.                            89.00         45.00             6            60
PARKER & PARSLEY 83-A, LTD.                            112.50         94.00             6            60
PARKER & PARSLEY 83-B, LTD.                            135.00         96.11             5           105
PARKER & PARSLEY 84-A, LTD.                            165.00        101.11             8           175
PARKER & PARSLEY 85-A, LTD.                                --            --            --            --
PARKER & PARSLEY 85-B, LTD.                            135.00        100.00             4            35
PARKER & PARSLEY 86-A, LTD.                            160.00         65.00             4            45
PARKER & PARSLEY 86-B, LTD.                            160.00         97.00             8           120
PARKER & PARSLEY 86-C, LTD.                            135.00         95.45             4            40
PARKER & PARSLEY 87-A, LTD.                            163.75         78.00            12           128
PARKER & PARSLEY 87-B, LTD.                            179.25        105.66            14           255
PARKER & PARSLEY PRODUCING PROPERTIES 87-A, LTD.       280.00        184.00             2            12
PARKER & PARSLEY PRODUCING PROPERTIES 87-B, LTD.       310.00        146.00             3            47
PARKER & PARSLEY 88-A, L.P.                            205.00        135.00             6            43
PARKER & PARSLEY 88-B, L.P.                            188.12        128.00             3           230
PARKER & PARSLEY 88-C, L.P.                            175.00        138.20             4            17
PARKER & PARSLEY PRODUCING PROPERTIES 88-A, L.P.           --            --            --            --
PARKER & PARSLEY 89-A, L.P.                            221.00        140.00             7           100
PARKER & PARSLEY 89-B, L.P.                            215.00        215.00             1             5
PARKER & PARSLEY 90-A, L.P.                            230.00        126.11             3            35
PARKER & PARSLEY 90-B, L.P.                            211.12        100.00            19           275
PARKER & PARSLEY 90-C, L.P.                            210.00        112.30            12           251
PARKER & PARSLEY 91-A, L.P.                            259.00        212.00             2            22
PARKER & PARSLEY 91-B, L.P.                            235.11        235.11             1            10



                                                                 PER $1,000 INVESTMENT
                                                  -------------------------------------------------------
                                                         FOR THE YEAR ENDED DECEMBER 31, 1999
                                                  -----------------------------------------------------
                                                         SALES PRICE
                                                  -------------------------     NUMBER        NUMBER
                                                      HIGH           LOW        OF SALES       SOLD
                                                  -----------   -----------   -----------   -----------
                                                                                
PARKER & PARSLEY 82-1, LTD.                       $     15.00   $      4.17             2            24
PARKER & PARSLEY 82-11, LTD.                            30.83         10.50             3            41
PARKER & PARSLEY 83-A, LTD.                             54.00         36.75            10           151
PARKER & PARSLEY 83-B, LTD.                             63.11         43.00             2            35
PARKER & PARSLEY 84-A, LTD.                             72.00         44.00             8           104
PARKER & PARSLEY 85-A, LTD.                             61.00         10.00             5            50
PARKER & PARSLEY 85-B, LTD.                             75.00         75.00             2            30
PARKER & PARSLEY 86-A, LTD.                             55.00         10.00             2            40
PARKER & PARSLEY 86-B, LTD.                            111.00         62.34             9           108
PARKER & PARSLEY 86-C, LTD.                             80.00         45.00             5            32
PARKER & PARSLEY 87-A, LTD.                            112.00         65.00            10           155
PARKER & PARSLEY 87-B, LTD.                            101.67         10.00            12           205
PARKER & PARSLEY PRODUCING PROPERTIES 87-A, LTD.       175.00        112.00             4            79
PARKER & PARSLEY PRODUCING PROPERTIES 87-B, LTD.       170.00        128.00             3            30
PARKER & PARSLEY 88-A, L.P.                            105.11         57.00             3            25
PARKER & PARSLEY 88-B, L.P.                            111.00         62.00             4            50
PARKER & PARSLEY 88-C, L.P.                             56.00         56.00             1            25
PARKER & PARSLEY PRODUCING PROPERTIES 88-A, L.P.       225.00        225.00             1             4
PARKER & PARSLEY 89-A, L.P.                            138.00         86.00             5            70
PARKER & PARSLEY 89-B, L.P.                            146.11        105.00             5            85
PARKER & PARSLEY 90-A, L.P.                             92.00         84.33             2            25
PARKER & PARSLEY 90-B, L.P.                            175.00         90.00            12           115
PARKER & PARSLEY 90-C, L.P.                            136.33         60.51             8           125
PARKER & PARSLEY 91-A, L.P.                            121.00         88.00             2            13
PARKER & PARSLEY 91-B, L.P.                            135.00        135.00             1            10





----------

(a)      This table contains historical information about recent trades of
         partnership interests on a per $1,000 investment as determined from
         "The Partnership Spectrum." The price information represents the prices
         reported to have been paid to the sellers net of commissions paid by
         buyers. This information should not be relied upon as any indication of
         the price at which the partnership interests may trade. There may have
         been other secondary sale transactions in the partnership interests,
         although no information regarding any such transactions is available to
         Pioneer USA. Because the information regarding sale transactions in the
         partnership interests in this table is provided without verification by
         Pioneer USA and because the information provided does not reflect
         sufficient activity to cause the prices shown to be representative of
         the market values of the partnership interests, the information should
         not be relied upon as indicative of the ability of limited partners to
         sell their partnership interests in secondary sale transactions or as
         to the prices at which the partnership interests may be sold.




                                      A-16
   118



                                    TABLE 16

     RESERVE VALUE ATTRIBUTABLE TO PIONEER USA, NONMANAGING GENERAL PARTNERS
                              AND LIMITED PARTNERS
                              AS OF MARCH 31, 2001





                                                                                    TOTAL RESERVE VALUE
                                                           ---------------------------------------------------------------------
                                                                              NONMANAGING           LIMITED
                                                           PIONEER USA (b) GENERAL PARTNERS (c)   PARTNERS (d)        TOTAL
                                                           --------------  -------------------   --------------   --------------
                                                                                                      
PARKER & PARSLEY 81-I, LTD.                                $      233,228     $       16,900     $      627,135   $      877,263
PARKER & PARSLEY 81-II, LTD.                                      146,961              6,020            453,478          606,459
PARKER & PARSLEY 82-I, LTD.                                       393,196             13,799            834,595        1,241,590
PARKER & PARSLEY 82-II, LTD.                                      424,071             13,255          1,163,695        1,601,021
PARKER & PARSLEY 82-III, LTD.                                     313,019             10,254            785,449        1,108,722
PARKER & PARSLEY 83-A, LTD.                                       948,058             37,495          2,585,378        3,570,931
PARKER & PARSLEY 83-B, LTD.                                     1,236,570             48,512          3,335,105        4,620,187
PARKER & PARSLEY 84-A, LTD.                                     1,298,417             57,301          3,737,727        5,093,445
PARKER & PARSLEY 85-A, LTD.                                        39,856                 --          1,322,363        1,362,219
PARKER & PARSLEY 85-B, LTD.                                        19,449                 --          1,112,104        1,131,553
PARKER & PARSLEY PRIVATE INVESTMENT 85-A, LTD.                     49,589                 --          1,419,276        1,468,865
PARKER & PARSLEY SELECTED 85 PRIVATE INVESTMENT, LTD.              24,427                 --            884,085          908,512
PARKER & PARSLEY 86-A, LTD.                                        23,434                 --          1,722,717        1,746,151
PARKER & PARSLEY 86-B, LTD.                                        65,922                 --          3,730,534        3,796,456
PARKER & PARSLEY 86-C, LTD.                                        40,095                 --          3,026,477        3,066,572
PARKER & PARSLEY PRIVATE INVESTMENT 86, LTD.                       12,491                 --          1,236,632        1,249,123
PARKER & PARSLEY 87-A CONV., LTD.                                  13,737                 --            709,821          723,558
PARKER & PARSLEY 87-A, LTD.                                        86,204                 --          5,297,076        5,383,280
PARKER & PARSLEY 87-B CONV., LTD.                                  11,562                 --            950,922          962,484
PARKER & PARSLEY 87-B, LTD.                                        48,024                 --          3,882,724        3,930,748
PARKER & PARSLEY PRODUCING PROPERTIES 87-A, LTD.                   33,772                 --          2,470,550        2,504,322
PARKER & PARSLEY PRODUCING PROPERTIES 87-B, LTD.                   62,095                 --          2,333,847        2,395,942
PARKER & PARSLEY PRIVATE INVESTMENT 87, LTD.                       29,690                 --          2,939,297        2,968,987
PARKER & PARSLEY 88-A CONV., L.P.                                  21,059                 --            892,537          913,596
PARKER & PARSLEY 88-A, L.P.                                        72,408                 --          3,043,164        3,115,572
PARKER & PARSLEY 88-B CONV., L.P.                                  17,830                 --          1,136,555        1,154,385
PARKER & PARSLEY 88-B, L.P.                                        57,973                 --          2,784,810        2,842,783
PARKER & PARSLEY 88-C CONV., L.P.                                  11,955                 --            914,613          926,568
PARKER & PARSLEY 88-C, L.P.                                         7,948                 --            652,411          660,359
PARKER & PARSLEY PRODUCING PROPERTIES 88-A, L.P.                   31,168                 --          1,815,156        1,846,324
PARKER & PARSLEY PRIVATE INVESTMENT 88, L.P.                       33,947                 --          3,360,773        3,394,720
PARKER & PARSLEY 89-A CONV., L.P.                                   9,130                 --            903,870          913,000
PARKER & PARSLEY 89-A, L.P.                                        61,080                 --          2,653,766        2,714,846
PARKER & PARSLEY 89-B CONV., L.P.                                  23,101                 --          1,735,034        1,758,135
PARKER & PARSLEY 89-B, L.P.                                        39,166                 --          1,894,254        1,933,420
PARKER & PARSLEY PRIVATE INVESTMENT 89, L.P.                       29,689                 --          1,872,378        1,902,067
PARKER & PARSLEY 90-A CONV., L.P.                                   8,840                 --            548,022          556,862
PARKER & PARSLEY 90-A, L.P.                                        50,432                 --          1,557,365        1,607,797
PARKER & PARSLEY 90-B CONV., L.P.                                  52,858                 --          3,120,422        3,173,280
PARKER & PARSLEY 90-B, L.P.                                       108,063                 --          8,504,751        8,612,814
PARKER & PARSLEY 90-C CONV., L.P.                                  25,475                 --          1,801,539        1,827,014
PARKER & PARSLEY 90-C, L.P.                                        35,856                 --          2,901,292        2,937,148
PARKER & PARSLEY PRIVATE INVESTMENT 90, L.P.                       52,622                 --          3,361,143        3,413,765
PARKER & PARSLEY 90 SPRABERRY PRIVATE DEV., L.P.                   15,168                 --          1,501,657        1,516,825
PARKER & PARSLEY 91-A, L.P.                                        65,170                 --          4,645,707        4,710,877
PARKER & PARSLEY 91-B, L.P.                                        54,289                 --          4,935,469        4,989,758
                                                           --------------     --------------     --------------   --------------
                                TOTAL                      $    6,439,094     $      203,536     $  103,097,675   $  109,740,305
                                                           ==============     ==============     ==============   ==============





----------

(a)  The reserve value is one of the components of the merger value for each
     partnership and represents the present value of estimated future net
     revenues from the partnership's estimated oil and gas reserves as of March
     31, 2001. The present value was calculated using: (1) a five-year New York
     Mercantile Exchange, or NYMEX, futures price for oil and gas as of March
     31, 2001 with prices held constant after year five at the year five price,
     less standard industry adjustments, (2) historical operating costs adjusted
     only for those items affected by commodity prices, such as production taxes
     and ad valorem taxes, and (3) a 10.0% discount rate. For 2001, the oil and
     gas prices were based on the average NYMEX futures price for the nine-month
     period beginning on April 1, 2001 and ending December 31, 2001.

(b)  Represents Pioneer USA's partnership interests in each partnership as: (1)
     the sole or managing general partner of the partnership; (2) a limited
     partner of the partnership; and (3) the sole general partner of each
     nonmanaging general partner. Pioneer USA will not receive any Pioneer
     common stock or cash payment for its partnership interests in any
     participating partnership. However, as a result of the merger of each
     participating partnership, Pioneer USA will acquire 100% of the properties
     of the partnership including properties attributable to its partnership
     interests in the partnerships.

(c)  Represents four unaffiliated individuals' partnership interests as limited
     partners of each nonmanaging general partner. Excludes Pioneer USA's
     partnership interests as general partner of each nonmanaging general
     partner.

(d)  Represents the partnership interests of unaffiliated limited partners of
     each partnership. Excludes Pioneer USA's partnership interests as a limited
     partner of any partnership.



                                      A-17
   119

                                   APPENDIX B
                                       TO
                           PROXY STATEMENT/PROSPECTUS

                         [TO BE PROVIDED BY AMENDMENT]




                                      B-1
   120

                                   APPENDIX C
                                       TO
                           PROXY STATEMENT/PROSPECTUS

                            SUMMARY RESERVE REPORT OF
                     WILLIAMSON PETROLEUM CONSULTANTS, INC.
                              FOR THE PARTNERSHIPS
                             AS OF DECEMBER 31, 2000



April 10, 2001


Pioneer Natural Resources USA, Inc.
5205 North O'Connor Boulevard, Suite 1400
Irving, Texas  75039

Attention Board of Directors

Gentlemen:

Subject: Letter Report Including 46 Reports Prepared
         by Williamson Petroleum Consultants, Inc.
         for Pioneer Natural Resources USA, Inc.
         to the Interests of Limited Partners
         or the Converted Limited Partners
         in Various Parker & Parsley Partnerships
         Managed by Pioneer Natural Resources USA, Inc.
         Effective December 31, 2000
         for Disclosure to the
         Securities and Exchange Commission
         Williamson Project 0.8839

In accordance with your request, Williamson Petroleum Consultants, Inc.
(Williamson) has prepared this summary letter for inclusion in the proxy
statement to be distributed to the limited partners of the referenced
partnerships by Pioneer Natural Resources USA, Inc. (Pioneer USA). This letter
includes 46 Williamson reports prepared for Pioneer USA to the interests of the
limited partners or the converted limited partners in various Parker & Parsley
partnerships managed by Pioneer USA effective December 31, 2000 for disclosure
to the Securities and Exchange Commission (SEC). A listing of the 46 Williamson
reports is included as Exhibit I.


I. ESTIMATED RESERVES AND ESTIMATED FUTURE NET REVENUES

The total Williamson estimated net proved reserves that are attributable to the
evaluated interests of the 46 partnership reports are shown in Exhibit II and
were based on economic parameters and operating condition considered applicable
as of December 31, 2000 and may be used in disclosure to the SEC.

The present values of the estimated future net revenues from proved reserves
were calculated using a discount rate of 10.00 percent per annum and were
computed in accordance with the financial reporting requirements of the SEC and
are presented in Exhibit II.



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Pioneer Natural Resources USA, Inc.
Board of Directors
April 10, 2001
Page 2



At the request of Pioneer USA, Williamson used the Landmark graphics and
reserves and economics evaluation software, Aries, to prepare this summary
report. In evaluations of these properties prior to December 31, 1991,
Williamson utilized its proprietary software programs. No comparative tests have
been performed to determine the difference in evaluation results of either
reserves or revenue quantities that may occur solely as a result of the
differences in the programs nor has Williamson performed tests to determine the
accuracy of Aries. However, in accordance with the request made by Pioneer USA
and the general acceptance of Aries by the oil and gas industry, Williamson has
used Aries to prepare this report.


II.  DEFINITIONS OF SEC RESERVES(1)

The estimated reserves presented in this summary letter are net proved reserves,
including proved developed producing, proved developed nonproducing, and proved
undeveloped reserves, and were computed in accordance with the financial
reporting requirements of the SEC. In preparing these evaluations, no attempt
has been made to quantify the element of uncertainty associated with any
category. Reserves were assigned to each category as warranted. The definitions
of oil and gas reserves pursuant to the requirements of the Securities Exchange
Act are:

Proved Reserves(2)

Proved reserves are the estimated quantities of crude oil, natural gas, and
natural gas liquids which geological and engineering data demonstrate with
reasonable certainty to be recoverable in future years from known reservoirs
under the economic criteria employed and existing operating conditions, i.e.,
prices and costs as of the date the estimate is made. Prices and costs include
consideration of changes provided only by contractual arrangements but not on
escalations based upon an estimate of future conditions.

----------

(1)  For evaluations prepared for disclosure to the Securities and Exchange
     Commission, see SEC Accounting Rules. Commerce Clearing House, Inc. October
     1981, Paragraph 290, Regulation 210.4-10, p. 329.

(2)  Any variations to these definitions will be clearly stated in the report.




                                      C-2
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Pioneer Natural Resources USA, Inc.
Board of Directors
April 10, 2001
Page 3



A.   Reservoirs are considered proved if economic producibility is supported by
     either actual production or conclusive formation test. The area of a
     reservoir considered proved includes:

     1.   that portion delineated by drilling and defined by gas-oil and/or
          oil-water contacts, if any; and

     2.   the immediately adjoining portions not yet drilled, but which can be
          reasonably judged as economically productive on the basis of available
          geological and engineering data. In the absence of information on
          fluid contacts, the lowest known structural occurrence of hydrocarbons
          controls the lower proved limit of the reservoir.

B.   Reserves which can be produced economically through application of improved
     recovery techniques (such as fluid injection) are included in the "proved"
     classification when successful testing by a pilot project, or the operation
     of an installed program in the reservoir, provides support for the
     engineering analysis on which the project or program was based.

C.   Estimates of proved reserves do not include the following:

     1.   oil that may become available from known reservoirs but is classified
          separately as "indicated additional reserves";

     2.   crude oil, natural gas, and natural gas liquids, the recovery of which
          is subject to reasonable doubt because of uncertainty as to geology,
          reservoir characteristics, or economic factors;

     3.   crude oil, natural gas, and natural gas liquids, that may occur in
          undrilled prospects; and

     4.   crude oil, natural gas, and natural gas liquids, that may be recovered
          from oil shales, coal(3), gilsonite, and other such sources.

----------

(3)  According to Staff Accounting Bulletin 85, excluding certain coalbed
     methane gas.



                                      C-3
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Pioneer Natural Resources USA, Inc.
Board of Directors
April 10, 2001
Page 4



Proved Developed Reserves(4)

Proved developed reserves are reserves that can be expected to be recovered
through existing wells with existing equipment and operating methods. Additional
oil and gas expected to be obtained through the application of fluid injection
or other improved recovery techniques for supplementing the natural forces and
mechanisms of primary recovery should be included as "proved developed reserves"
only after testing by a pilot project or after the operation of an installed
program has confirmed through production response that increased recovery will
be achieved.

Proved Undeveloped Reserves

Proved undeveloped reserves are reserves that are expected to be recovered from
new wells on undrilled acreage, or from existing wells where a relatively major
expenditure is required for recompletion. Reserves on undrilled acreage shall be
limited to those drilling units offsetting productive units that are reasonably
certain of production when drilled. Proved reserves for other undrilled units
can be claimed only where it can be demonstrated with certainty that there is
continuity of production from the existing productive formation. Under no
circumstances should estimates for proved undeveloped reserves be attributable
to any acreage for which an application of fluid injection or other improved
recovery technique is contemplated, unless such techniques have been proved
effective by actual tests in the area and in the same reservoir.

----------

(4)  Williamson Petroleum Consultants, Inc. separates proved developed reserves
     into proved developed producing and proved developed nonproducing reserves.
     This is to identify proved developed producing reserves as those to be
     recovered from actively producing wells; proved developed nonproducing
     reserves as those to be recovered from wells or intervals within wells,
     which are completed but shut in waiting on equipment or pipeline
     connections, or wells where a relatively minor expenditure is required for
     recompletion to another zone.



                                      C-4
   124

Pioneer Natural Resources USA, Inc.
Board of Directors
April 10, 2001
Page 5



III.  DISCUSSION OF SEC RESERVES

The properties evaluated in this report are located in the states of Oklahoma
and Texas with the majority of the value in the Spraberry (Trend Area) field,
Texas.

The individual projections of lease reserves and economics prepared to produce
this summary report include data that describe the production forecasts and
associated evaluation parameters such as interests, taxes, product prices,
operating costs, investments, salvage values, abandonment costs, and net profit
interests.

Net income to the evaluated interests is the future net revenue after
consideration of royalty revenue payable to others, taxes, operating expenses,
investments, salvage values, abandonment costs, and net profit interests, as
applicable. The future net revenue is before federal income tax and excludes
consideration of any encumbrances against the properties if such exist.

The future net revenue values presented in this report were based on projections
of oil and gas production. It was assumed there would be no significant delay
between the date of oil and gas production and the receipt of the associated
revenue for this production. No opinion is expressed by Williamson in this
report as to a fair market value of the evaluated properties.

Unless specifically identified and documented by Pioneer USA as having
curtailment problems, gas production trends have been assumed to be a function
of well productivity and not of market conditions. The effect of "take or pay"
clauses in gas contracts was not considered.

Oil and natural gas liquids (NGL) reserves are expressed in thousands of United
States (U.S.) barrels (MBBL) of 42 U.S. gallons. Gas volumes are expressed in
millions of cubic feet (MMCF) at 60 degrees Fahrenheit and at the legal pressure
base that prevails in the state which the reserves are located. No adjustment of
the individual gas volumes to a common pressure base has been made.

This report includes only those costs and revenues which are considered by
Pioneer USA to be directly attributable to individual leases and areas. There
could exist other revenues, overhead costs, or other costs associated with
Pioneer USA or the Limited Partners/Converted Limited Partners which are not
included in this report. Such additional costs and revenues are outside the
scope of this report. This report is not a financial statement for Pioneer USA
or the Limited Partners/Converted Limited Partners and should not be used as the
sole basis for any transaction concerning Pioneer USA, the Limited
Partners/Converted Limited Partners, or the evaluated properties.




                                      C-5
   125

Pioneer Natural Resources USA, Inc.
Board of Directors
April 10, 2001
Page 6



The reserves projections in this report are based on the use of the available
data and accepted industry engineering methods. Future changes in any
operational or economic parameters or production characteristics of the
evaluated properties could increase or decrease their reserves. Unforeseen
changes in market demand or allowables set by various regulatory agencies could
also cause actual production rates to vary from those projected. Williamson
reserves the right to alter any of the reserves projections and the associated
economics included in this evaluation in any future evaluations based on
additional data that may be acquired.

All data utilized in the preparation of this report with respect to interests,
reversionary status, oil and gas prices, gas categories, gas contract terms,
operating expenses, investments, salvage values, abandonment costs, net profit
interests, well information, and current operating conditions, as applicable,
were provided by Pioneer USA. Production data provided by Pioneer USA were
utilized. The production data was generally through October 2000. All data have
been reviewed for reasonableness and, unless obvious errors were detected, have
been accepted as correct. It should be emphasized that revisions to the
projections of reserves and economics included in this report may be required if
the provided data are revised for any reason. No inspection of the properties
was made as this was not considered within the scope of this evaluation. No
investigation was made of any environmental liabilities that might apply to the
evaluated properties, and no costs are included for any possible related
expenses.

Since sufficient production history and other data were available, the estimates
of reserves contained in this report were determined by extrapolation of
historical production trends and in accordance with the Definitions of SEC
Reserves included in this summary letter report.

Prices for oil sold as of December 31, 2000 were provided by Pioneer USA to be
used at the effective date. These prices include adjustments for API gravity,
transportation, and any bonus paid. These adjustments were made by Pioneer USA.
After the effective date, prices were held constant for the life of the
properties. No attempt has been made to account for oil price fluctuations which
have occurred in the market subsequent to the effective date of this report.

Prices for gas sold as of December 31, 2000 were provided by Pioneer USA to be
used at the effective date. These prices include adjustments for British thermal
unit content, shrinkage due to NGL removal, transportation and handling charges,
and any other known differences between sales and produced volumes. These
adjustments were made by Pioneer USA. After the effective date, prices were held
constant for the life of the properties unless Pioneer USA indicated



                                      C-6
   126

Pioneer Natural Resources USA, Inc.
Board of Directors
April 10, 2001
Page 7




that changes were provided for by contract. All gas prices were applied to
projected wellhead volumes.

Prices for NGL sold as of December 31, 2000 were provided by Pioneer USA to be
used at the effective date. NGL reserves were projected as a separate stream
using a constant ratio (barrels of NGL/thousand cubic feet of gas) based on
historical yields. After the effective date, prices were held constant for the
life of the properties. No attempt has been made to account for price
fluctuations which have occurred in the market subsequent to the effective date
of this report.

It should be emphasized that with the current economic uncertainties,
fluctuation in market conditions could significantly change the economics of the
properties included in this report.

Operating expenses were provided by Pioneer USA and represented, when possible,
the latest available 12-month average of all recurring expenses which are
billable to the working interest owners. These expenses included, but were not
limited to, all direct operating expenses, field overhead costs, and any ad
valorem taxes not deducted separately. Expenses for workovers, well
stimulations, and other maintenance were not included in the operating expenses
unless such work was expected on a recurring basis. Judgments for the exclusion
of the nonrecurring expenses were made by Pioneer USA. Operating costs were held
constant for the life of the properties.

State production and county ad valorem taxes have been deducted at the published
rates as provided by Pioneer USA. A 7.5 percent severance tax exemption was
applied until September 2001 for qualifying wells.

IV.  CONSENT AND DECLARATION OF INDEPENDENT STATUS

We understand that our estimates are to be included in a Schedule 13e-3 under
the Securities Exchange Act of 1934 to be filed by you with the SEC and in the
proxy statement included as an exhibit to such Schedule 13e-3. We understand
further that the estimates may be used by you to establish merger values for the
Partnerships. With this understanding in mind, we have consistently applied the
generally accepted petroleum engineering and evaluation principles in estimating
the proved oil and gas reserves and in computing the future net revenues derived
from such reserves for each property attributable to the interests held by the
Partnerships.

Based on information supplied by Pioneer USA, neither capital costs nor salvage
values were included in the projections of reserves and economics in this
report.

Williamson is an independent consulting firm and does not own any interests in
the oil and gas properties covered by this report. No employee, officer, or
director of Williamson is an employee, officer, or director of Pioneer USA or
any of the



                                      C-7
   127

Pioneer Natural Resources USA, Inc.
Board of Directors
April 10, 2001
Page 8



subject partnerships. Neither the employment of nor the compensation received by
Williamson is contingent upon the values assigned to the properties covered by
this report.

Yours very truly,

/s/ Williamson Petroleum Consultants, Inc.

WILLIAMSON PETROLEUM CONSULTANTS, INC.

JDS/chk

Enclosures




                                      C-8
   128

                                    EXHIBIT I

                   LETTER REPORT INCLUDING 46 REPORTS PREPARED
                    BY WILLIAMSON PETROLEUM CONSULTANTS, INC.
                     FOR PIONEER NATURAL RESOURCES USA, INC.
                      TO THE INTERESTS OF LIMITED PARTNERS
                        OR THE CONVERTED LIMITED PARTNERS
                    IN VARIOUS PARKER & PARSLEY PARTNERSHIPS
                 MANAGED BY PIONEER NATURAL RESOURCES USA, INC.
                           EFFECTIVE DECEMBER 31, 2000
                              FOR DISCLOSURE TO THE
                       SECURITIES AND EXCHANGE COMMISSION
                            WILLIAMSON PROJECT 0.8839

             LIST OF WILLIAMSON PETROLEUM CONSULTANTS, INC. REPORTS
                           EFFECTIVE DECEMBER 31, 2000

"Evaluation of Oil and Gas Reserves to the Interests of the Limited Partners in
Parker & Parsley 81-I, Ltd. Managed by Pioneer Natural Resources USA, Inc.
Effective December 31, 2000 for Disclosure to the Securities and Exchange
Commission Summary Report Utilizing Aries Software Williamson Project 0.8839"

"Evaluation of Oil and Gas Reserves to the Interests of the Limited Partners in
Parker & Parsley 81-II, Ltd. Managed by Pioneer Natural Resources USA, Inc.
Effective December 31, 2000 for Disclosure to the Securities and Exchange
Commission Summary Report Utilizing Aries Software Williamson Project 0.8839"

"Evaluation of Oil and Gas Reserves to the Interests of the Limited Partners in
Parker & Parsley 82-I, Ltd. Managed by Pioneer Natural Resources USA, Inc.
Effective December 31, 2000 for Disclosure to the Securities and Exchange
Commission Summary Report Utilizing Aries Software Williamson Project 0.8839"

"Evaluation of Oil and Gas Reserves to the Interests of the Limited Partners in
Parker & Parsley 82-II, Ltd. Managed by Pioneer Natural Resources USA, Inc.
Effective December 31, 2000 for Disclosure to the Securities and Exchange
Commission Summary Report Utilizing Aries Software Williamson Project 0.8839"

"Evaluation of Oil and Gas Reserves to the Interests of the Limited Partners in
Parker & Parsley 82-III, Ltd. Managed by Pioneer Natural Resources USA, Inc.
Effective December 31, 2000 for Disclosure to the Securities and Exchange
Commission Summary Report Utilizing Aries Software Williamson Project 0.8839"

"Evaluation of Oil and Gas Reserves to the Interests of the Limited Partners in
Parker & Parsley 83-A, Ltd. Managed by Pioneer Natural Resources USA, Inc.
Effective December 31, 2000 for Disclosure to the Securities and Exchange
Commission Summary Report Utilizing Aries Software Williamson Project 0.8839"

"Evaluation of Oil and Gas Reserves to the Interests of the Limited Partners in
Parker & Parsley 83-B, Ltd. Managed by Pioneer Natural Resources USA, Inc.
Effective December 31, 2000 for Disclosure to the Securities and Exchange
Commission Summary Report Utilizing Aries Software Williamson Project 0.8839"

"Evaluation of Oil and Gas Reserves to the Interests of the Limited Partners in
Parker & Parsley 84-A, Ltd. Managed by Pioneer Natural Resources USA, Inc.
Effective December 31, 2000 for Disclosure to the Securities and Exchange
Commission Summary Report Utilizing Aries Software Williamson Project 0.8839"

"Evaluation of Oil and Gas Reserves to the Interests of the Limited Partners in
Parker & Parsley 85-A, Ltd. Managed by Pioneer Natural Resources USA, Inc.
Effective December 31, 2000 for Disclosure to the Securities and Exchange
Commission Summary Report Utilizing Aries Software Williamson Project 0.8839"

"Evaluation of Oil and Gas Reserves to the Interests of the Limited Partners in
Parker & Parsley 85-B, Ltd. Managed by Pioneer Natural Resources USA, Inc.
Effective December 31, 2000 for Disclosure to the Securities and Exchange
Commission Summary Report Utilizing Aries Software Williamson Project 0.8839"



                                      C-9
   129
                                    EXHIBIT I

                   LETTER REPORT INCLUDING 46 REPORTS PREPARED
                    BY WILLIAMSON PETROLEUM CONSULTANTS, INC.
                     FOR PIONEER NATURAL RESOURCES USA, INC.
                      TO THE INTERESTS OF LIMITED PARTNERS
                        OR THE CONVERTED LIMITED PARTNERS
                    IN VARIOUS PARKER & PARSLEY PARTNERSHIPS
                 MANAGED BY PIONEER NATURAL RESOURCES USA, INC.
                           EFFECTIVE DECEMBER 31, 2000
                              FOR DISCLOSURE TO THE
                       SECURITIES AND EXCHANGE COMMISSION
                            WILLIAMSON PROJECT 0.8839

             LIST OF WILLIAMSON PETROLEUM CONSULTANTS, INC. REPORTS
                           EFFECTIVE DECEMBER 31, 2000


"Evaluation of Oil and Gas Reserves to the Interests of the Limited Partners in
Parker & Parsley Private Investment 85-A, Ltd. Managed by Pioneer Natural
Resources USA, Inc. Effective December 31, 2000 for Disclosure to the Securities
and Exchange Commission Summary Report Utilizing Aries Software Williamson
Project 0.8839"

"Evaluation of Oil and Gas Reserves to the Interests of the Limited Partners in
Parker & Parsley Selected 85 Private Investment, Ltd. Managed by Pioneer Natural
Resources USA, Inc. Effective December 31, 2000 for Disclosure to the Securities
and Exchange Commission Summary Report Utilizing Aries Software Williamson
Project 0.8839"

"Evaluation of Oil and Gas Reserves to the Interests of the Limited Partners in
Parker & Parsley 86-A, Ltd. Managed by Pioneer Natural Resources USA, Inc.
Effective December 31, 2000 for Disclosure to the Securities and Exchange
Commission Summary Report Utilizing Aries Software Williamson Project 0.8839"

"Evaluation of Oil and Gas Reserves to the Interests of the Limited Partners in
Parker & Parsley 86-B, Ltd. Managed by Pioneer Natural Resources USA, Inc.
Effective December 31, 2000 for Disclosure to the Securities and Exchange
Commission Summary Report Utilizing Aries Software Williamson Project 0.8839"

"Evaluation of Oil and Gas Reserves to the Interests of the Limited Partners in
Parker & Parsley 86-C, Ltd. Managed by Pioneer Natural Resources USA, Inc.
Effective December 31, 2000 for Disclosure to the Securities and Exchange
Commission Summary Report Utilizing Aries Software Williamson Project 0.8839"

"Evaluation of Oil and Gas Reserves to the Interests of the Limited Partners in
Parker & Parsley Private Investment 86, Ltd. Managed by Pioneer Natural
Resources USA, Inc. Effective December 31, 2000 for Disclosure to the Securities
and Exchange Commission Summary Report Utilizing Aries Software Williamson
Project 0.8839"

"Evaluation of Oil and Gas Reserves to the Interests of the Converted Limited
Partners in Parker & Parsley 87-A Converted, Ltd. Managed by Pioneer Natural
Resources USA, Inc. Effective December 31, 2000 for Disclosure to the Securities
and Exchange Commission Summary Report Utilizing Aries Software Williamson
Project 0.8839"

"Evaluation of Oil and Gas Reserves to the Interests of the Limited Partners in
Parker & Parsley 87-A, Ltd. Managed by Pioneer Natural Resources USA, Inc.
Effective December 31, 2000 for Disclosure to the Securities and Exchange
Commission Summary Report Utilizing Aries Software Williamson Project 0.8839"

"Evaluation of Oil and Gas Reserves to the Interests of the Converted Limited
Partners in Parker & Parsley 87-B Converted, Ltd. Managed by Pioneer Natural
Resources USA, Inc. Effective December 31, 2000 for Disclosure to the Securities
and Exchange Commission Summary Report Utilizing Aries Software Williamson
Project 0.8839"

"Evaluation of Oil and Gas Reserves to the Interests of the Limited Partners in
Parker & Parsley 87-B, Ltd. Managed by Pioneer Natural Resources USA, Inc.
Effective December 31, 2000 for Disclosure to the Securities and Exchange
Commission Summary Report Utilizing Aries Software Williamson Project 0.8839"



                                      C-10
   130
                                    EXHIBIT I

                   LETTER REPORT INCLUDING 46 REPORTS PREPARED
                    BY WILLIAMSON PETROLEUM CONSULTANTS, INC.
                     FOR PIONEER NATURAL RESOURCES USA, INC.
                      TO THE INTERESTS OF LIMITED PARTNERS
                        OR THE CONVERTED LIMITED PARTNERS
                    IN VARIOUS PARKER & PARSLEY PARTNERSHIPS
                 MANAGED BY PIONEER NATURAL RESOURCES USA, INC.
                           EFFECTIVE DECEMBER 31, 2000
                              FOR DISCLOSURE TO THE
                       SECURITIES AND EXCHANGE COMMISSION
                            WILLIAMSON PROJECT 0.8839

             LIST OF WILLIAMSON PETROLEUM CONSULTANTS, INC. REPORTS
                           EFFECTIVE DECEMBER 31, 2000


"Evaluation of Oil and Gas Reserves to the Interests of the Limited Partners in
Parker & Parsley Producing Properties 87-A, Ltd. Managed by Pioneer Natural
Resources USA, Inc. Effective December 31, 2000 for Disclosure to the Securities
and Exchange Commission Summary Report Utilizing Aries Software Williamson
Project 0.8839"

"Evaluation of Oil and Gas Reserves to the Interests of the Limited Partners in
Parker & Parsley Producing Properties 87-B, Ltd. Managed by Pioneer Natural
Resources USA, Inc. Effective December 31, 2000 for Disclosure to the Securities
and Exchange Commission Summary Report Utilizing Aries Software Williamson
Project 0.8839"

"Evaluation of Oil and Gas Reserves to the Interests of the Limited Partners in
Parker & Parsley Private Investment 87, Ltd. Managed by Pioneer Natural
Resources USA, Inc. Effective December 31, 2000 for Disclosure to the Securities
and Exchange Commission Summary Report Utilizing Aries Software Williamson
Project 0.8839"

"Evaluation of Oil and Gas Reserves to the Interests of the Converted Limited
Partners in Parker & Parsley 88-A Converted, L.P. Managed by Pioneer Natural
Resources USA, Inc. Effective December 31, 2000 for Disclosure to the Securities
and Exchange Commission Summary Report Utilizing Aries Software Williamson
Project 0.8839"

"Evaluation of Oil and Gas Reserves to the Interests of the Limited Partners in
Parker & Parsley 88-A, L.P. Managed by Pioneer Natural Resources USA, Inc.
Effective December 31, 2000 for Disclosure to the Securities and Exchange
Commission Summary Report Utilizing Aries Software Williamson Project 0.8839"

"Evaluation of Oil and Gas Reserves to the Interests of the Converted Limited
Partners in Parker & Parsley 88-B Converted, L.P. Managed by Pioneer Natural
Resources USA, Inc. Effective December 31, 2000 for Disclosure to the Securities
and Exchange Commission Summary Report Utilizing Aries Software Williamson
Project 0.8839"

"Evaluation of Oil and Gas Reserves to the Interests of the Limited Partners in
Parker & Parsley 88-B, L.P. Managed by Pioneer Natural Resources USA, Inc.
Effective December 31, 2000 for Disclosure to the Securities and Exchange
Commission Summary Report Utilizing Aries Software Williamson Project 0.8839"

"Evaluation of Oil and Gas Reserves to the Interests of the Converted Limited
Partners in Parker & Parsley 88-C Converted, L.P. Managed by Pioneer Natural
Resources USA, Inc. Effective December 31, 2000 for Disclosure to the Securities
and Exchange Commission Summary Report Utilizing Aries Software Williamson
Project 0.8839"

"Evaluation of Oil and Gas Reserves to the Interests of the Limited Partners in
Parker & Parsley 88-C, L.P. Managed by Pioneer Natural Resources USA, Inc.
Effective December 31, 2000 for Disclosure to the Securities and Exchange
Commission Summary Report Utilizing Aries Software Williamson Project 0.8839"



                                      C-11
   131
                                    EXHIBIT I

                   LETTER REPORT INCLUDING 46 REPORTS PREPARED
                    BY WILLIAMSON PETROLEUM CONSULTANTS, INC.
                     FOR PIONEER NATURAL RESOURCES USA, INC.
                      TO THE INTERESTS OF LIMITED PARTNERS
                        OR THE CONVERTED LIMITED PARTNERS
                    IN VARIOUS PARKER & PARSLEY PARTNERSHIPS
                 MANAGED BY PIONEER NATURAL RESOURCES USA, INC.
                           EFFECTIVE DECEMBER 31, 2000
                              FOR DISCLOSURE TO THE
                       SECURITIES AND EXCHANGE COMMISSION
                            WILLIAMSON PROJECT 0.8839

             LIST OF WILLIAMSON PETROLEUM CONSULTANTS, INC. REPORTS
                           EFFECTIVE DECEMBER 31, 2000


"Evaluation of Oil and Gas Reserves to the Interests of the Limited Partners in
Parker & Parsley Producing Properties 88-A, L.P. Managed by Pioneer Natural
Resources USA, Inc. Effective December 31, 2000 for Disclosure to the Securities
and Exchange Commission Summary Report Utilizing Aries Software Williamson
Project 0.8839"

"Evaluation of Oil and Gas Reserves to the Interests of the Limited Partners in
Parker & Parsley Private Investment 88, L.P. Managed by Pioneer Natural
Resources USA, Inc. Effective December 31, 2000 for Disclosure to the Securities
and Exchange Commission Summary Report Utilizing Aries Software Williamson
Project 0.8839"

"Evaluation of Oil and Gas Reserves to the Interests of the Converted Limited
Partners in Parker & Parsley 89-A Converted, L.P. Managed by Pioneer Natural
Resources USA, Inc. Effective December 31, 2000 for Disclosure to the Securities
and Exchange Commission Summary Report Utilizing Aries Software Williamson
Project 0.8839"

"Evaluation of Oil and Gas Reserves to the Interests of the Limited Partners in
Parker & Parsley 89-A, L.P. Managed by Pioneer Natural Resources USA, Inc.
Effective December 31, 2000 for Disclosure to the Securities and Exchange
Commission Summary Report Utilizing Aries Software Williamson Project 0.8839"

"Evaluation of Oil and Gas Reserves to the Interests of the Converted Limited
Partners in Parker & Parsley 89-B Converted, L.P. Managed by Pioneer Natural
Resources USA, Inc. Effective December 31, 2000 for Disclosure to the Securities
and Exchange Commission Summary Report Utilizing Aries Software Williamson
Project 0.8839"

"Evaluation of Oil and Gas Reserves to the Interests of the Limited Partners in
Parker & Parsley 89-B, L.P. Managed by Pioneer Natural Resources USA, Inc.
Effective December 31, 2000 for Disclosure to the Securities and Exchange
Commission Summary Report Utilizing Aries Software Williamson Project 0.8839"

"Evaluation of Oil and Gas Reserves to the Interests of the Limited Partners in
Parker & Parsley Private Investment 89, L.P. Managed by Pioneer Natural
Resources USA, Inc. Effective December 31, 2000 for Disclosure to the Securities
and Exchange Commission Summary Report Utilizing Aries Software Williamson
Project 0.8839"

"Evaluation of Oil and Gas Reserves to the Interests of the Converted Limited
Partners in Parker & Parsley 90-A Converted, L.P. Managed by Pioneer Natural
Resources USA, Inc. Effective December 31, 2000 for Disclosure to the Securities
and Exchange Commission Summary Report Utilizing Aries Software Williamson
Project 0.8839"

"Evaluation of Oil and Gas Reserves to the Interests of the Limited Partners in
Parker & Parsley 90-A, L.P. Managed by Pioneer Natural Resources USA, Inc.
Effective December 31, 2000 for Disclosure to the Securities and Exchange
Commission Summary Report Utilizing Aries Software Williamson Project 0.8839"




                                      C-12
   132
                                    EXHIBIT I

                   LETTER REPORT INCLUDING 46 REPORTS PREPARED
                    BY WILLIAMSON PETROLEUM CONSULTANTS, INC.
                     FOR PIONEER NATURAL RESOURCES USA, INC.
                      TO THE INTERESTS OF LIMITED PARTNERS
                        OR THE CONVERTED LIMITED PARTNERS
                    IN VARIOUS PARKER & PARSLEY PARTNERSHIPS
                 MANAGED BY PIONEER NATURAL RESOURCES USA, INC.
                           EFFECTIVE DECEMBER 31, 2000
                              FOR DISCLOSURE TO THE
                       SECURITIES AND EXCHANGE COMMISSION
                            WILLIAMSON PROJECT 0.8839

             LIST OF WILLIAMSON PETROLEUM CONSULTANTS, INC. REPORTS
                           EFFECTIVE DECEMBER 31, 2000


"Evaluation of Oil and Gas Reserves to the Interests of the Converted Limited
Partners in Parker & Parsley 90-B Converted, L.P. Managed by Pioneer Natural
Resources USA, Inc. Effective December 31, 2000 for Disclosure to the Securities
and Exchange Commission Summary Report Utilizing Aries Software Williamson
Project 0.8839"

"Evaluation of Oil and Gas Reserves to the Interests of the Limited Partners in
Parker & Parsley 90-B, L.P. Managed by Pioneer Natural Resources USA, Inc.
Effective December 31, 2000 for Disclosure to the Securities and Exchange
Commission Summary Report Utilizing Aries Software Williamson Project 0.8839"

"Evaluation of Oil and Gas Reserves to the Interests of the Converted Limited
Partners in Parker & Parsley 90-C Converted, L.P. Managed by Pioneer Natural
Resources USA, Inc. Effective December 31, 2000 for Disclosure to the Securities
and Exchange Commission Summary Report Utilizing Aries Software Williamson
Project 0.8839"

"Evaluation of Oil and Gas Reserves to the Interests of the Limited Partners in
Parker & Parsley 90-C, L.P. Managed by Pioneer Natural Resources USA, Inc.
Effective December 31, 2000 for Disclosure to the Securities and Exchange
Commission Summary Report Utilizing Aries Software Williamson Project 0.8839"

"Evaluation of Oil and Gas Reserves to the Interests of the Limited Partners in
Parker & Parsley Private Investment 90, L.P. Managed by Pioneer Natural
Resources USA, Inc. Effective December 31, 2000 for Disclosure to the Securities
and Exchange Commission Summary Report Utilizing Aries Software Williamson
Project 0.8839"

"Evaluation of Oil and Gas Reserves to the Interests of the Limited Partners in
Parker & Parsley 90 Spraberry Private Development, L.P. Managed by Pioneer
Natural Resources USA, Inc. Effective December 31, 2000 for Disclosure to the
Securities and Exchange Commission Summary Report Utilizing Aries Software
Williamson Project 0.8839"

"Evaluation of Oil and Gas Reserves to the Interests of the Limited Partners in
Parker & Parsley 91-A, L.P. Managed by Pioneer Natural Resources USA, Inc.
Effective December 31, 2000 for Disclosure to the Securities and Exchange
Commission Summary Report Utilizing Aries Software Williamson Project 0.8839"

"Evaluation of Oil and Gas Reserves to the Interests of the Limited Partners in
Parker & Parsley 91-B, L.P. Managed by Pioneer Natural Resources USA, Inc.
Effective December 31, 2000 for Disclosure to the Securities and Exchange
Commission Summary Report Utilizing Aries Software Williamson Project 0.8839"




                                      C-13
   133

                                   EXHIBIT II

                   LETTER REPORT INCLUDING 46 REPORTS PREPARED
                    BY WILLIAMSON PETROLEUM CONSULTANTS, INC.
                     FOR PIONEER NATURAL RESOURCES USA, INC.
                      TO THE INTERESTS OF LIMITED PARTNERS
                        OR THE CONVERTED LIMITED PARTNERS
                    IN VARIOUS PARKER & PARSLEY PARTNERSHIPS
                 MANAGED BY PIONEER NATURAL RESOURCES USA, INC.
                           EFFECTIVE DECEMBER 31, 2000
                              FOR DISCLOSURE TO THE
                       SECURITIES AND EXCHANGE COMMISSION
                            WILLIAMSON PROJECT 0.8839

                       NET RESERVES AND FUTURE NET REVENUE
         FROM REPORTS PREPARED BY WILLIAMSON PETROLEUM CONSULTANTS, INC.
                           EFFECTIVE DECEMBER 31, 2000




                                                                      TOTAL PROVED DEVELOPED PRODUCING
                                            ---------------------------------------------------------------------------------
                                                                                                  FUTURE NET REVENUE, M$
                                                        NET RESERVES TO                       -------------------------------
                                                     THE EVALUATED INTERESTS                                    DISCOUNTED
                                            --------------------------------------------                            PER
                                            OIL/CONDENSATE       LIQUID           GAS                            ANNUM AT
PIONEER FUNDS                                   (MBBL)           (MBBL)          (MMCF)       UNDISCOUNTED     10.00 PERCENT
-------------                               --------------      -------         --------      -------------    --------------
                                                                                                
Parker & Parsley 81-I, Ltd                      99.997           58.388          320.081        2,810.911        1,436.523
Parker & Parsley 81-II, Ltd.                    84.731           67.440          222.749        1,977.257        1,062.283
Parker & Parsley 82-I, Ltd.                    194.780           73.613          603.859        4,656.049        2,419.619
Parker & Parsley 82-II, Ltd.                   211.725           94.426          467.740        4,879.008        2,416.761
Parker & Parsley 82-III, Ltd.                  164.851           68.468          223.717        2,916.207        1,539.389
Parker & Parsley 83-A, Ltd.                    497.915          281.533        1,156.089       11,168.739        5,649.205
Parker & Parsley 83-B, Ltd.                    608.901          345.775        1,553.450       14,112.492        7,165.928
Parker & Parsley 84-A, Ltd.                    608.956          403.376        1,678.388       15,623.823        7,676.646
Parker & Parsley 85-A, Ltd.                    243.615          134.904          512.744        5,195.717        2,783.387
Parker & Parsley 85-B, Ltd.                    201.444           99.966          455.062        4,490.151        2,308.454
Parker & Parsley Private
  Investment  85-A, Ltd.                       228.363           96.999          353.440        5,194.664        2,383.495
Parker & Parsley Selected
  85 Private Investment, Ltd.                  130.193           99.486          381.116        3,650.520        1,810.634
Parker & Parsley 86-A, Ltd.                    250.327          197.841          859.633        7,179.394        3,574.162
Parker & Parsley 86-B, Ltd.                    618.084          308.191        1,200.966       14,120.080        7,029.228
Parker & Parsley 86-C, Ltd.                    563.752          325.531        1,246.684       11,898.910        6,501.998
Parker & Parsley Private
  Investment 86, Ltd.                          208.138          106.060          491.002        4,920.619        2,468.192
Parker  & Parsley 87-A Conv., Ltd.             113.696           66.277          287.292        2,873.802        1,450.827
Parker & Parsley 87-A, Ltd                     834.588          487.044        2,112.270       21,154.029       10,747.196
Parker & Parsley 87-B Conv., Ltd.              157.541           88.713          365.167        3,907.545        1,832.825
Parker & Parsley 87-B, Ltd.                    643.391          362.299        1,491.327       15,958.265        7,485.189
Parker & Parsley Producing
  Properties 87-A, Ltd.                        553.134          153.947          705.887        9,228.521        4,636.341
Parker & Parsley Producing
  Properties 87-B, Ltd.                        348.562          183.827          852.462        9,400.038        4,368.675
Parker & Parsley Private
  Investment 87, Ltd.                          525.646          229.811          959.391       12,336.452        5,141.312
Parker & Parsley 88-A Conv., L.P.              144.189           81.404          314.160        3,480.240        1,705.478
Parker & Parsley 88-A, L.P.                    491.675          277.590        1,071.291       11,868.418        5,816.075
Parker & Parsley 88-B Conv., L.P.              185.600           84.916          353.516        4,354.398        2,077.136
Parker & Parsley 88-B, L.P.                    457.018          209.116          870.573       10,723.127        5,115.146
Parker & Parsley 88-C Conv., L.P.              145.815           74.419          309.894        3,561.005        1,706.767



                                      C-14
   134
                                   EXHIBIT II

                   LETTER REPORT INCLUDING 46 REPORTS PREPARED
                    BY WILLIAMSON PETROLEUM CONSULTANTS, INC.
                     FOR PIONEER NATURAL RESOURCES USA, INC.
                      TO THE INTERESTS OF LIMITED PARTNERS
                        OR THE CONVERTED LIMITED PARTNERS
                    IN VARIOUS PARKER & PARSLEY PARTNERSHIPS
                 MANAGED BY PIONEER NATURAL RESOURCES USA, INC.
                           EFFECTIVE DECEMBER 31, 2000
                              FOR DISCLOSURE TO THE
                       SECURITIES AND EXCHANGE COMMISSION
                            WILLIAMSON PROJECT 0.8839

                       NET RESERVES AND FUTURE NET REVENUE
         FROM REPORTS PREPARED BY WILLIAMSON PETROLEUM CONSULTANTS, INC.
                           EFFECTIVE DECEMBER 31, 2000




                                                                      TOTAL PROVED DEVELOPED PRODUCING
                                            ---------------------------------------------------------------------------------
                                                                                                  FUTURE NET REVENUE, M$
                                                        NET RESERVES TO                       -------------------------------
                                                     THE EVALUATED INTERESTS                                    DISCOUNTED
                                            --------------------------------------------                            PER
                                            OIL/CONDENSATE       LIQUID           GAS                            ANNUM AT
PIONEER FUNDS                                   (MBBL)           (MBBL)          (MMCF)       UNDISCOUNTED     10.00 PERCENT
-------------                               --------------      -------         --------      -------------    --------------
                                                                                                
Parker & Parsley 88-C, L.P.                    103.921           53.036          220.852        2,537.908        1,216.403
Parker & Parsley Producing
  Properties 88-A, L.P.                        273.838          149.368          558.886        6,727.211        3,225.257
Parker & Parsley Private
  Investment 88, L.P.                          509.333          253.748          928.143       12,668.293        5,826.092
Parker & Parker  89-A Conv., L.P.              136.107           64.524          282.306        3,433.908        1,667.718
Parker & Parsley 89-A, L.P.                    404.668          191.841          839.377       10,210.849        4,959.027
Parker & Parsley 89-B Conv., L.P.              276.640          159.018          597.289        6,717.103        3,379.724
Parker & Parsley 89-B, L.P.                    304.369          175.038          657.490        7,386.746        3,718.741
Parker & Parsley Private
  Investment 89, L.P.                          324.948          138.741          489.327        6,929.194        3,302.639
Parker & Parsley 90-A Conv., L.P.               86.964           46.820          168.458        2,004.818        1,042.228
Parker & Parsley 90-A, L.P.                    253.836          136.323          490.071        5,806.774        3,011.223
Parker & Parsley 90-B Conv., L.P.              503.298          242.511          965.950       11,527.923        5,694.202
Parker & Parsley 90-B, L.P.                  1,370.202          658.317        2,621.779       31,316.135       15,461.210
Parker & Parsley 90-C Conv., L.P.              323.794          138.198          463.058        6,302.167        3,212.933
Parker & Parsley 90-C, L.P.                    520.528          222.164          744.398       10,131.499        5,165.181
Parker  & Parsley Private
  Investment 90, L.P.                          584.599          228.964          801.496       12,370.155        5,691.401
Parker & Parsley 90
  Spraberry Private Development, L.P.          313.028          100.516          377.597        5,906.691        2,549.362
Parker & Parsley 91-A, L.P.                    662.796          306.258        1,409.517       17,786.756        8,134.929
Parker & Parsley 91-B, L.P.                    719.664          311.695        1,213.315       17,109.740        8,280.085
                                            ----------        ---------       ----------      -----------      -----------
Total All Partnerships                      17,189.160        8,638.440       35,249.259      400,514.251      195,847.226






                                      C-15
   135

                                   APPENDIX D
                                       TO
                           PROXY STATEMENT/PROSPECTUS

                                     FORM OF
                FAIRNESS OPINION OF ROBERT A. STANGER & CO., INC.
                               (SUBJECT TO CHANGE)

                                                         , 2001


Board of Directors of
Pioneer Natural Resources USA, Inc.,
As the Sole or Managing General Partner of
The Partnerships Identified on Exhibit I
1400 Williams Square West
5205 North O'Connor Boulevard
Irving, Texas 75039

Gentlemen:


         Pioneer Natural Resources USA, Inc. ("Pioneer USA"), the sole or
managing general partner of the partnerships identified in Exhibit I attached
hereto ("the Partnerships"), has advised us that the Partnerships are
contemplating a transaction (the "Transaction") pursuant to an agreement (the
"Merger Agreement") in which the Partnerships will merge with and into Pioneer
USA and the interests of the limited partners (the "Limited Partners") in each
Partnership will be converted into the right to receive shares of common stock
(the "Pioneer Parent Shares") of Pioneer Natural Resources Company ("Pioneer
Parent") equal to the estimated value of such Partnership's oil and gas reserves
(the "Reserve Value") and net working capital (the "Working Capital Balance") as
of March 31, 2001 (collectively, the Reserve Value and the Working Capital
Balance are referred to herein as the "Merger Value"). We have been advised that
the Merger Value will be allocated and paid to holders of limited partnership
interests (the "Limited Partner Interests") of each Partnership in accordance
with the provisions of the Partnership agreement of each Partnership relating to
a liquidation of the Partnership.

         We have been further advised that the Reserve Value has been
established by Pioneer USA and its parent company, Pioneer Parent, based upon
the present value of estimated future net revenues (after certain expenses and
charges) from each Partnership's proved oil and gas reserves as of March 31,
2001 utilizing prices for 2001, 2002, 2003, 2004 and thereafter of $26.17,
$24.36, $22.83, $22.31 and $21.97 per barrel of oil and $5.18, $4.61, $4.16,
$4.09 and $4.12 per thousand cubic feet of gas, and a discount rate of 10.0%.
[We have been further advised that the Reserve Value is based upon the reserve
report of Pioneer USA and Pioneer Parent, as reviewed by Williamson Petroleum
Consultants, Inc. ("Williamson"), an independent petroleum engineering firm, as
of March 31, 2001, and to which Pioneer USA and Pioneer Parent applied the
prices previously stated (the "Reserve Analysis").]

         We have been advised that the Limited Partners in each Partnership will
have the opportunity to approve or reject the participation by their Partnership
in the Transaction pursuant to a proxy statement/prospectus (the "Proxy
Statement/Prospectus") and a Limited Partners meeting which will be prepared and
held, respectively, in connection with the Transaction, and further that Limited
Partners in each Partnership, in exchange for Limited Partner Interests, will




                                      D-1
   136

receive the allocated Merger Value in Pioneer Parent Shares. We have been
advised that the value to be ascribed to each share of Pioneer Parent, which is
listed on the New York Stock Exchange ("NYSE"), shall be equal to the average
closing price for such shares on the NYSE for the ten trading day period ending
three business days prior to the initial meeting of the Limited Partners
contemplated herein.


         You have requested that Robert A. Stanger & Co., Inc. ("Stanger")
provide an opinion as to the fairness from a financial point of view to the
unaffiliated Limited Partners of each Partnership and the unaffiliated limited
partners of the non-managing general partner of each applicable Partnership of
the Merger Value ascribed to each Partnership and the allocation thereof to: (i)
the Limited Partners of each Partnership, as a group; (ii) the general partners
of each Partnership as a group; (iii) Pioneer USA, as the managing or sole
general partner of each partnership; (iv) the unaffiliated Limited Partners of
each Partnership, as a group; and (v) the unaffiliated limited partners of the
non-managing general partner of each applicable Partnership as a group.

         Stanger, founded in 1978, has provided research, investment banking and
consulting services to clients located throughout the United States, including
major New York Stock Exchange member firms and insurance companies and over
seventy companies engaged in the management and operations of partnerships. The
investment banking activities of Stanger include financial advisory services,
asset and securities valuations, industry and company research and analysis,
litigation support and expert witness services, and due diligence investigations
in connection with both publicly registered and privately placed securities
transactions.

         Stanger, as part of its investment banking business, is regularly
engaged in the valuation of securities in connection with mergers, acquisitions,
and reorganizations and for estate, tax, corporate and other purposes. In
particular, Stanger's valuation practice principally involves partnerships,
partnership securities and assets typically owned through partnerships
including, but not limited to, oil and gas reserves, real estate, mortgages
secured by real estate, cable television systems, and equipment leasing assets.

         In arriving at the opinion set forth below, we have:

         o    Reviewed the Preliminary Proxy Statement/Prospectus;

         o    Reviewed a draft of the Merger Agreement which Pioneer USA has
              indicated to be in substantially the form which will be executed
              in connection with the Transaction;

         o    Reviewed the financial statements and forms 10K and 10Q, as
              applicable, of the Partnerships for the years ended December 31,
              1998, 1999 and 2000, and the three months ended March 31, 2001;


         o    [Reviewed the Reserve Report for each Partnership reviewed by
              Williamson Petroleum Consultants, Inc. as of March 31, 2001;]



                                      D-2
   137


         o    Reviewed the calculations prepared by Pioneer USA and Pioneer
              Parent of the Merger Value per $1,000 original investment in each
              Partnership;


         o    Reviewed Pioneer USA's analysis of other alternatives to the
              Transaction including going concern value, liquidation value,
              royalty trust and production payment;


         o    Reviewed estimates prepared by Pioneer USA and Pioneer Parent of
              the going-concern value and liquidation value per $1,000 original
              investment in each Partnership;


         o    Interviewed key management personnel of Pioneer USA regarding the
              oil and gas reserves, the financial condition of each Partnership
              and the terms of the Transaction;


         o    Reviewed the financial statements of Pioneer Parent for the years
              ended December 31, 1999 and 2000 and the three months ended March
              31, 2001;

         o    Reviewed pro forma financial data for Pioneer Parent assuming the
              completion of the transaction;


         o    Reviewed recent secondary market trading activity for interests in
              the Partnerships, as available;


         o    Reviewed recent trading activity in Pioneer Parent Shares; and


         o    Conducted such other studies, analyses, inquiries and
              investigations as we deemed appropriate.


         In rendering this opinion, we have relied, without independent
verification, on the accuracy and completeness in all material respects of all
financial and other information that was furnished or otherwise communicated to
us by Pioneer USA, Pioneer Parent and the Partnerships. We have been advised by
Pioneer USA and Pioneer Parent that the oil and gas properties owned by the
Partnerships are subject to operating agreements (the "Operating Agreements")
with Pioneer USA and that: (i) such Operating Agreements provide for the payment
of overhead charges and that such charges are reasonable compared to amounts
charged for similar services by third-party operators; and (ii) except for
cause, such Operating Agreements do not provide for the termination of Pioneer
USA as operator, and (iii) such Operating Agreements do not provide for the
revision of overhead charges, except as escalated under the terms of such
Operating Agreements. Furthermore, we have been advised by Pioneer USA and
Pioneer Parent that if each Partnership's reserves were offered for sale to a
third party, a condition of such sale would be that the oil and gas reserves
would continue to be subject to the Operating Agreements with Pioneer USA which
provide for the payment of overhead charges, and that it would be appropriate to
assume, when estimating the value of such reserves, that such charges would
continue. We have also been advised that the Reserve Value and Working Capital
Balance of each Partnership has been properly allocated between Pioneer USA, the
other general partners, if any, and Limited Partners of each Partnership in
accordance with the Partnership Agreement with respect to a liquidation of such
Partnership.




                                      D-3
   138


         We have not performed an independent appraisal of the oil and gas
reserves or other assets and liabilities of the Partnerships. [We have not
conducted any engineering studies and have relied on estimates of Pioneer USA
and Pioneer Parent, which were reviewed by Williamson Petroleum Consultants,
Inc., with respect to oil and gas reserve volumes, prices, operating costs, and
overhead charges.]

         We have relied on the assurance of Pioneer USA, Pioneer Parent and the
Partnerships that: (i) the Reserve Analysis provided to us was in the judgment
of Pioneer USA and the Partnerships reasonably prepared on bases consistent with
actual historical experience and reflect their best currently available
estimates and good faith judgments; (ii) any estimates of costs to remediate
environmental conditions included in the Reserve Analysis are based on detailed
analyses and reflect the best currently available estimates and good faith
judgments; (iii) any historical financial data, balance sheet data, transaction
cost estimates, Merger Value analyses, going-concern value analyses and
liquidation value analyses are accurate and complete in all material respects;
(iv) all allocations included within the calculations of Merger Values,
going-concern values and liquidation values have been made in accordance with
the Partnership Agreement for each Partnership; (v) no material changes have
occurred in the information reviewed or in the value of the oil and gas reserves
or Working Capital Balances of each Partnership between the date the information
was provided to us and the date of this letter; (vi) the relative ownership
interest of the Limited Partners, unaffiliated Limited Partners, general
partners, unaffiliated limited partners of the non-managing general partner of
each applicable Partnership and Pioneer USA, as manager or sole general partner,
is accurately included in accordance with the Partnership Agreements on the
analyses provided to us by Pioneer USA; (vii) neither Pioneer Parent or any of
its affiliates has during the thirty days prior to the date hereof commenced or
continued a share repurchase program or similar transaction which could affect
the Pioneer Parent Share price to be used in the Transaction; and (viii) Pioneer
USA, Pioneer Parent and the Partnerships are not aware of any information or
facts regarding the Partnerships, the oil and gas properties, the Reserve
Analysis or the Working Capital Balances of each Partnership that would cause
the information supplied to us to be incomplete or misleading in any material
respect.

         We have not been requested to, and therefore did not: (i) make any
recommendation to Pioneer USA, the Partnerships or the Limited Partners with
respect to whether to approve or reject the Transaction; (ii) determine or
negotiate the amount or form of the Merger Value to be paid for Limited Partner
Interests in the Transaction; (iii) offer the assets of the Partnerships for
sale to any third party; (iv) express any opinion as to: (a) the impact of the
Transaction with respect to Pioneer USA or the Limited Partners of any
Partnerships that do not participate in the Transaction; (b) the tax
consequences of the Transaction for Pioneer USA, other general partners or the
Limited Partners of any Partnership; (c) Pioneer USA's or Pioneer Parent's
ability to finance their obligations pursuant to the Merger Agreement or the
impact of a failure to obtain financing on the financial performance of Pioneer
USA, Pioneer Parent or the Partnerships; (d) Pioneer USA's decision to estimate
the Reserve Value of the oil and gas reserves of each Partnership based upon the
continued operation of the properties by Pioneer USA and the payment of overhead
charges in accordance with existing Operating Agreements or the impact, if any,
on the estimated values of the Partnerships' oil and gas reserves if Pioneer USA
and Pioneer Parent determined to offer or operate the assets subject to revised
Operating Agreements; (e) whether or not alternative methods of determining the
Merger Value would have also provided fair results or results substantially
similar to the methodology used; (f) alternatives to the





                                      D-4
   139


Transaction, including the offering of such assets for sale to third-party
buyers; (g) the trading price of Pioneer Parent Shares immediately following the
closing of the Transaction and the distribution of Pioneer Parent Shares in
connection therewith; (h) the fairness of the termination of the repurchase
obligations of Pioneer USA with respect to those partnerships wherein Pioneer
USA is obligated to offer to repurchase limited partnership interests annually
based upon a formula which, in certain circumstances including the repurchase
offers based upon December 31, 2000 oil and gas prices, result in repurchase
offer prices above the market value for the reserves of such Partnerships; or
(i) any other terms of the Transaction.


         This letter does not purport to be a complete description of the
analyses performed or the matters considered in rendering this opinion. The
analyses and the summary set forth herein must be considered as a whole, and
selecting portions of such summary or analyses without considering all factors
and analyses would create an incomplete view of the process underlying this
opinion. In rendering this opinion, judgment was applied to a variety of complex
analyses and assumptions. The assumptions made and the judgments applied in
rendering the opinion are not readily susceptible to partial analysis or summary
description. The fact that any specific analysis is referred to herein is not
meant to indicate that such analysis was given greater weight than any other
analyses.

         Our opinion is based on business, economic, oil and gas market, and
other conditions as of the date of our analysis and addresses the Merger Value
in the context of information available as of the date of our analysis. Events
occurring after that date could affect the value of the assets of the
Partnerships or the assumptions used in preparing this opinion.

         Based upon and subject to the foregoing, it is our opinion that, as of
the date of this letter and subject to the assumptions, limitations and
qualifications contained herein, the Merger Value ascribed to each Partnership
in connection with the Transaction and the allocation thereof to: (i) the
Limited Partners of each Partnership, as a group; (ii) the general partners of
each Partnership, as a group; (iii) Pioneer USA, as the managing or sole general
partner of each Partnership; (iv) the unaffiliated Limited Partners of each
Partnership, as a group; and (v) the unaffiliated limited partners of the
non-managing general partner of each applicable Partnership, as a group; is fair
to the unaffiliated Limited Partners of each Partnership and the unaffiliated
limited partners of the non-managing general partner of each applicable
Partnership, from a financial point of view.


Yours truly,


Robert A. Stanger & Co., Inc.
Shrewsbury, New Jersey
       , 2001



                                      D-5
   140

                                                                       EXHIBIT I

                                  PARTNERSHIPS


Parker & Parsley 81-I, Ltd.
Parker & Parsley 81-II, Ltd.
Parker & Parsley 82-I, Ltd.
Parker & Parsley 82-II, Ltd.
Parker & Parsley 82-III, Ltd.
Parker & Parsley 83-A, Ltd.
Parker & Parsley 83-B, Ltd.
Parker & Parsley 84-A, Ltd.
Parker & Parsley 85-A, Ltd.
Parker & Parsley 85-B, Ltd.
Parker & Parsley Private Investment 85-A, Ltd.
Parker& Parsley Selected 85 Private Investment, Ltd.
Parker & Parsley 86-A, Ltd.
Parker & Parsley 86-B, Ltd.
Parker & Parsley 86-C, Ltd.
Parker & Parsley Private Investment 86, Ltd.
Parker & Parsley 87-A Conv., Ltd.
Parker & Parsley 87-A, Ltd.
Parker & Parsley 87-B Conv., Ltd.
Parker & Parsley 87-B, Ltd.
Parker & Parsley Producing Properties 87-A, Ltd.
Parker & Parsley Producing Properties 87-B, Ltd.
Parker & Parsley Private Investment 87, Ltd.
Parker & Parsley 88-A Conv., Ltd.
Parker & Parsley 88-A, L.P.
Parker & Parsley 88-B Conv., L.P.
Parker & Parsley 88-B, L.P.
Parker & Parsley 88-C Conv., L.P.
Parker & Parsley 88-C, L.P.
Parker & Parsley Producing Properties 88-A, L.P.
Parker & Parsley Private Investment 88, L.P.
Parker & Parsley 89-A Conv., L.P.
Parker & Parsley 89-A, L.P.
Parker & Parsley 89-B Conv., L.P.
Parker & Parsley 89-B, L.P.
Parker & Parsley Private Investment 89, L.P.
Parker & Parsley 90-A Conv., L.P.
Parker & Parsley 90-A, L.P.
Parker & Parsley 90-B Conv., L.P.
Parker & Parsley 90-B, L.P.
Parker & Parsley 90-C Conv., L.P.
Parker & Parsley 90-C, L.P.
Parker & Parsley Private Investment 90, L.P.
Parker & Parsley 90 Spraberry Private Development, L.P.
Parker & Parsley 91-A, L.P.
Parker & Parsley 91-B, L.P.




                                      D-6
   141

                                   APPENDIX E

                                       TO

                           PROXY STATEMENT/PROSPECTUS


                              THE MERGER PROPOSALS

     The merger proposals for each partnership, except as otherwise indicated,
are set forth below. For each partnership, the merger proposals include the
approval of:

     o   the merger agreement for that partnership, pursuant to which:

         --   the partnership will be merged with and into Pioneer USA, on the
              terms and subject to the conditions set forth in the merger
              agreement as described in the proxy statement/prospectus; and


         --   each partner, whether limited or general, but other than Pioneer
              USA, will receive Pioneer Parent common stock in an amount based
              on the merger value of that partnership in exchange for that
              partner's partnership interests;


     o   the merger amendment for that partnership authorizing:

         --   the merger of the partnership with and into Pioneer USA, with
              Pioneer USA being the surviving entity; and

         --   the elimination of any restrictions on the merger otherwise
              contained in the partnership's partnership agreement; and

     o   the opinion of special legal counsel for the limited partners and the
         selection of that counsel.


     For each partnership, approval of the merger proposals requires the
affirmative vote of limited partners who own or have the power to vote a
majority, or 66-2/3% for Parker & Parsley 91-A, L.P. and Parker & Parsley 91-B,
L.P., of the limited partnership interests in that partnership. The effect of an
abstention or a failure to vote is the same as a vote against the merger
proposals. See "The Special Meetings -- Record Date; Voting Rights and Proxies."
Subject to the terms and conditions of the merger of each partnership as
described in the proxy statement/prospectus under "The Merger Agreement," if the
merger proposals are approved by a partnership, that participating partnership
will merge with and into Pioneer USA, with Pioneer USA being the surviving
entity. From and after the closing of the merger of each participating
partnership, the partnership interests of the partners in that partnership will
represent the right to receive an amount of Pioneer Parent common stock as
described in the proxy statement/prospectus.


     Generally, the partnership agreement of each partnership requires that
special legal counsel for the limited partners, acceptable to the partnership,
deliver a legal opinion, acceptable to the partnership, that (1) neither the
grant nor the exercise of the right to approve the merger of the partnership by
its limited partners will adversely affect the federal income tax classification
of the partnership or any of its limited partners and (2) neither the grant nor
exercise of such right will result in the loss of any limited partner's limited
liability. of Dallas, Texas has delivered that opinion, subject to the approval
of the limited partners of that opinion and the selection of special legal
counsel for the limited partners. See "The Merger of Each Partnership -- Legal
Opinion for Limited Partners."

APPROVAL OF MERGER FOR EACH PARTNERSHIP FORMED IN TEXAS:


     RESOLVED: That, subject to receipt of a favorable opinion of special legal
counsel for the limited partners as described in the proxy statement/prospectus,
the partnership be merged with and into Pioneer USA, with Pioneer USA being the
surviving entity, and that an amount of Pioneer Parent common stock be issued to
each partner, other than Pioneer USA, in accordance with the terms set forth in
the merger agreement included as Appendix F to the proxy statement/prospectus
and subject to the conditions set forth therein.




                                       E-1
   142

     RESOLVED: That, subject to receipt of a favorable opinion of special legal
counsel for the limited partners as described in the proxy statement/prospectus,
the following new article shall be added to the partnership agreement of the
partnership:

                                     ARTICLE

                      Notwithstanding any provisions of this Agreement to the
                  contrary, it is hereby agreed as follows:


                      1. Definitions. For the purposes of this Article, "Proxy
                  Statement/Prospectus" means the proxy statement/prospectus
                  dated , 2001 of Pioneer Natural Resources Company, a Delaware
                  corporation ("Pioneer Parent"), and Pioneer Natural Resources
                  USA, Inc., a Delaware corporation ("Pioneer USA"), contained
                  in the Registration Statement on Form S-4 (File No. 333-59094)
                  of Pioneer Parent filed with the Securities and Exchange
                  Commission.


                      2. Elimination of Restrictions to Transaction.
                  Notwithstanding anything in this Agreement to the contrary,
                  upon the consent of limited partners holding a majority of the
                  outstanding limited partnership interests in the partnership,
                  which consent may or may not be the same consent to the
                  adoption of an amendment to this Agreement, no provision of
                  this Agreement shall prohibit, limit or prevent:

                           (a) the merger or consolidation of the partnership,
                      including the merger described in the Proxy
                      Statement/Prospectus, with any other domestic limited
                      partnership or other entity, as those terms are defined in
                      the Texas Revised Limited Partnership Act, and

                           (b) the consummation of the merger of the partnership
                      as described in the Proxy Statement/Prospectus.

                  In addition, no consent of the partnership, Pioneer USA or any
                  partner or other procedure, including the delivery of opinions
                  of counsel, shall be required in order to enable the
                  partnership, Pioneer USA or any partner to effect the merger.

                      3. Mergers. For purposes of this Agreement, each merger
                  described in the Proxy Statement/Prospectus shall be treated
                  as if the partnership has:


                           (a) disposed of all of its assets and liabilities to
                      Pioneer USA in exchange for an amount of Pioneer Parent
                      common stock representing the merger value of the
                      partnership, and


                           (b) liquidated in the manner provided in the
                      liquidation provisions of this Agreement.


                  Accordingly, upon the partnership's deemed liquidation
                  resulting from the merger, Pioneer Parent will issue an amount
                  of Pioneer Parent common stock to the partners, other than
                  Pioneer USA, in accordance with the liquidation provisions of
                  this Agreement. For purposes of Texas law, the merger shall be
                  a merger subject to the provisions of Section 2.11 of the
                  Texas Revised Limited Partnership Act.


                      4. Authority of Pioneer USA as General Partner. By
                  obtaining the approval of the limited partners described in
                  Section 2 of this Article, the partnership hereby extends the
                  power of attorney granted to Pioneer USA pursuant to this
                  Agreement to permit Pioneer USA to execute the merger
                  agreement described in the Proxy Statement/Prospectus and the
                  merger amendment contemplated by this Article on behalf of the
                  limited partners. Pioneer USA shall be authorized, at such
                  time in its full discretion as it deems appropriate, to
                  execute, acknowledge, verify, deliver, file and record, for
                  and in the name and on behalf of the partnership, Pioneer USA
                  and the limited partners, any and all documents, agreements,
                  certificates and instruments, and shall do and perform any and
                  all acts required by applicable law or which Pioneer USA deems
                  necessary or advisable in order to give effect to this Article
                  and the transactions contemplated herein, including, but not
                  limited to, the merger.


                                      E-2
   143
                      5. This Article Controlling. The provisions of this
                  Article shall control over all other provisions of this
                  Agreement.

                  Except as herein expressly amended, all other terms and
                  provisions of this Agreement shall remain in full force and
                  effect.


APPROVAL OF MERGER FOR EACH PARTNERSHIP FORMED IN DELAWARE:


     RESOLVED: That, subject to receipt of a favorable opinion of special legal
counsel for the limited partners as described in the proxy statement/prospectus,
the partnership be merged with and into Pioneer USA, with Pioneer USA being the
surviving entity, and that an amount of Pioneer Parent common stock be issued to
each partner, other than Pioneer USA, in accordance with the terms set forth in
the merger agreement included as Appendix F to the proxy statement/prospectus
and subject to the conditions set forth therein.


     RESOLVED: That, subject to receipt of a favorable opinion of special legal
counsel for the limited partners as described in the proxy statement/prospectus,
the following new article shall be added to the partnership agreement of the
partnership:

                                     ARTICLE

                      Notwithstanding any provisions of this Agreement to the
                  contrary, it is hereby agreed as follows:


                      1. Definitions. For the purposes of this Article, "Proxy
                  Statement/Prospectus" means the proxy statement/prospectus
                  dated , 2001 of Pioneer Natural Resources Company, a Delaware
                  corporation ("Pioneer Parent"), and Pioneer Natural Resources
                  USA, Inc., a Delaware corporation ("Pioneer USA"), contained
                  in the Registration Statement on Form S-4 (File No. 333-59094)
                  of Pioneer Parent filed with the Securities and Exchange
                  Commission.


                      2. Elimination of Restrictions to Transaction.
                  Notwithstanding anything in this Agreement to the contrary,
                  upon the consent of limited partners holding a majority of the
                  outstanding limited partnership interests in the partnership,
                  which consent may or may not be the same consent to the
                  adoption of an amendment to this Agreement, no provision of
                  this Agreement shall prohibit, limit or prevent:

                           (a) the merger or consolidation of the partnership,
                      including the merger described in the Proxy
                      Statement/Prospectus, with any other domestic limited
                      partnership or other business entity, as those terms are
                      defined in the Delaware Revised Uniform Limited
                      Partnership Act, and

                           (b) the consummation of the merger of the partnership
                      as described in the Proxy Statement/Prospectus.

                  In addition, no consent of the partnership, Pioneer USA or any
                  partner or other procedure, including the delivery of opinions
                  of counsel, shall be required in order to enable the
                  partnership, Pioneer USA or any partner to effect the merger.

                      3. Mergers. For purposes of this Agreement, each merger
                  described in the Proxy Statement/Prospectus shall be treated
                  as if the partnership has:


                           (a) disposed of all of its assets and liabilities to
                      Pioneer USA in exchange for an amount of Pioneer Parent
                      common stock representing the merger value of the
                      partnership, and


                           (b) liquidated in the manner provided in the
                      liquidation provisions of this Agreement.



                                      E-3
   144

                  Accordingly, upon the partnership's deemed liquidation
                  resulting from the merger, Pioneer Parent will issue an amount
                  of Pioneer Parent common stock to the partners, other than
                  Pioneer USA, in accordance with the liquidation provisions of
                  this Agreement. For purposes of Delaware law, the merger shall
                  be a merger subject to the provisions of Section 17.11 of the
                  Delaware Revised Uniform Limited Partnership Act.


                      4. Authority of Pioneer USA as General Partner. By
                  obtaining the approval of the limited partners described in
                  Section 2 of this Article, the partnership hereby extends the
                  power of attorney granted to Pioneer USA pursuant to this
                  Agreement to permit Pioneer USA to execute the merger
                  agreement described in the Proxy Statement/Prospectus and the
                  merger amendment contemplated by this Article on behalf of the
                  limited partners. Pioneer USA shall be authorized, at such
                  time in its full discretion as it deems appropriate, to
                  execute, acknowledge, verify, deliver, file and record, for
                  and in the name and on behalf of the partnership, Pioneer USA
                  and the limited partners, any and all documents, agreements,
                  certificates and instruments, and shall do and perform any and
                  all acts required by applicable law or which Pioneer USA deems
                  necessary or advisable in order to give effect to this Article
                  and the transactions contemplated herein, including, but not
                  limited to, the merger.

                      5. This Article Controlling. The provisions of this
                  Article shall control over all other provisions of this
                  Agreement.

                  Except as herein expressly amended, all other terms and
                  provisions of this Agreement shall remain in full force and
                  effect.

APPROVAL OF COUNSEL TO LIMITED PARTNERS FOR EACH PARTNERSHIP:

     RESOLVED: That the selection of of Dallas, Texas as special legal counsel
for the limited partners of the partnership for the purpose of rendering the
legal opinion described in the proxy statement/prospectus under "The Merger of
Each Partnership -- Legal Opinion for Limited Partners" be and hereby is
approved by Pioneer USA, on behalf of the partnership, and the limited partners
of such partnership.

     RESOLVED: That the legal opinion delivered pursuant to the partnership
agreement of the partnership as described in the proxy statement/prospectus
under "The Merger of Each Partnership -- Legal Opinion for Limited Partners," in
form and substance as set forth in Exhibit A to these merger proposals, be and
hereby is approved as in form and substance satisfactory to the limited partners
of such partnership in their reasonable judgment.




                                      E-4
   145
                                    EXHIBIT A


                                  TO APPENDIX E


                                       TO

                           PROXY STATEMENT/PROSPECTUS

                                   OPINION OF



Pioneer Natural Resources USA, Inc.,
As Sole or Managing General Partner of
46 Limited Partnerships Named in the
Proxy Statement/Prospectus dated             , 2001
1400 Williams Square West
5205 North O'Connor Blvd.
Irving, Texas 75039

     We are of the opinion that (1) neither the grant nor the exercise of the
right to approve the merger of each partnership with and into Pioneer Natural
Resources USA, Inc. by the partnership's limited partners will adversely affect
the federal income tax classification of the partnership or any of its limited
partners and (2) neither the grant nor exercise of such right will result in the
loss of any limited partner's limited liability.


     We hereby consent to the references to our firm and this opinion contained
in the proxy statement/prospectus forming a part of the registration statement
on Form S-4 (File No. 333-59094) filed with the Securities and Exchange
Commission by Pioneer Natural Resources Company, a Delaware corporation, in
connection with the merger of each of the limited partnerships with and into
Pioneer Natural Resources USA, Inc., a Delaware corporation.






                                      E-5
   146

                                   APPENDIX F

                                       TO

                           PROXY STATEMENT/PROSPECTUS


                                     FORM OF

                          AGREEMENT AND PLAN OF MERGER
                           (DRILLING AND INCOME FUNDS)


         THIS AGREEMENT AND PLAN OF MERGER dated as of      , 2001 (this "Merger
Agreement"), is entered into by and among Pioneer Natural Resources Company, a
Delaware corporation ("Pioneer Parent"), Pioneer Natural Resources USA, Inc., a
Delaware corporation and wholly-owned subsidiary of Pioneer Parent ("Pioneer
USA"), and each of the limited partnerships referred to below (each, a
"Partnership" and collectively, the "Partnerships").


                                    RECITALS

         A.   Pioneer USA is the sole or managing general partner of each of the
following Partnerships:



                                                                     STATE OF
                       PARTNERSHIP NAME                             FORMATION
---------------------------------------------------------------  -----------------
                                                              
Parker & Parsley 81-I, Ltd.                                           Texas
Parker & Parsley 81-II, Ltd.                                          Texas
Parker & Parsley 82-I, Ltd.                                           Texas
Parker & Parsley 82-II, Ltd.                                          Texas
Parker & Parsley 82-III, Ltd.                                         Texas
Parker & Parsley 83-A, Ltd.                                           Texas
Parker & Parsley 83-B, Ltd.                                           Texas
Parker & Parsley 84-A, Ltd.                                           Texas
Parker & Parsley 85-A, Ltd.                                           Texas
Parker & Parsley 85-B, Ltd.                                           Texas
Parker & Parsley Private Investment 85-A, Ltd.                        Texas
Parker & Parsley Selected 85 Private Investment, Ltd.                 Texas
Parker & Parsley 86-A, Ltd.                                           Texas
Parker & Parsley 86-B, Ltd.                                           Texas
Parker & Parsley 86-C, Ltd.                                           Texas
Parker & Parsley Private Investment 86, Ltd.                          Texas
Parker & Parsley 87-A Conv., Ltd.                                     Texas
Parker & Parsley 87-A , Ltd.                                          Texas
Parker & Parsley 87-B Conv., Ltd.                                     Texas
Parker & Parsley 87-B, Ltd.                                           Texas
Parker & Parsley Producing Properties 87-A, Ltd.                      Texas
Parker & Parsley Producing Properties 87-B, Ltd.                      Texas
Parker & Parsley Private Investment 87, Ltd.                          Texas
Parker & Parsley 88-A Conv., L.P.                                    Delaware
Parker & Parsley 88-A, L.P.                                          Delaware
Parker & Parsley 88-B Conv., L.P.                                    Delaware
Parker & Parsley 88-B, L.P.                                          Delaware
Parker & Parsley 88-C Conv., L.P.                                    Delaware
Parker & Parsley 88-C, L.P.                                          Delaware
Parker & Parsley Producing Properties 88-A, L.P.                     Delaware
Parker & Parsley Private Investment 88, L.P.                         Delaware
Parker & Parsley 89-A Conv., L.P.                                    Delaware
Parker & Parsley 89-A, L.P.                                          Delaware
Parker & Parsley 89-B Conv., L.P.                                    Delaware



                                      F-1
   147



                                                                     STATE OF
                       PARTNERSHIP NAME                             FORMATION
---------------------------------------------------------------  -----------------
                                                              
Parker & Parsley 89-B, L.P.                                          Delaware
Parker & Parsley Private Investment 89, L.P.                         Delaware
Parker & Parsley 90-A Conv., L.P.                                    Delaware
Parker & Parsley 90-A, L.P.                                          Delaware
Parker & Parsley 90-B Conv., L.P.                                    Delaware
Parker & Parsley 90-B, L.P.                                          Delaware
Parker & Parsley 90-C Conv., L.P.                                    Delaware
Parker & Parsley 90-C, L.P.                                          Delaware
Parker & Parsley Private Investment 90, L.P.                         Delaware
Parker & Parsley 90 Spraberry Private Development, L.P.              Delaware
Parker & Parsley 91-A, L.P.                                          Delaware
Parker & Parsley 91-B, L.P.                                          Delaware



         B. Each of P&P Employees 81-I, Ltd., a Texas limited partnership, P&P
Employees 81-II, Ltd., a Texas limited partnership, P&P Employees 82-I, Ltd., a
Texas limited partnership, P&P Employees 82-II, Ltd., a Texas limited
partnership, P&P Employees 82-III, Ltd., a Texas limited partnership, P&P
Employees 83-A, Ltd., a Texas limited partnership, P&P Employees 83-B, Ltd., a
Texas limited partnership, and P&P Employees 84-A, Ltd., a Texas limited
partnership (individually, the "Nonmanaging General Partner" and collectively,
the "Nonmanaging General Partners"), is the nonmanaging general partner of
Parker & Parsley 81-I, Ltd., Parker & Parsley 81-II, Ltd., Parker & Parsley
82-I, Ltd., Parker & Parsley 82-II, Ltd., Parker & Parsley 82-III, Ltd., Parker
& Parsley 83-A, Ltd. Parker & Parsley 83-B, Ltd. and Parker & Parsley 84-A,
Ltd., respectively.


         C. Pioneer USA is the sole general partner of each of the Nonmanaging
General Partners and in such capacity has authority (i) to cause the Nonmanaging
General Partner to perform its obligations under the partnership agreement of
the respective Partnership; and (ii) to exercise on behalf of the Nonmanaging
General Partner all of the rights and elections granted to such Nonmanaging
General Partner by the respective Partnership.

         D. The board of directors of each of Pioneer Parent and Pioneer USA has
determined that it is in the best interests of Pioneer Parent and Pioneer USA
(in its individual capacity, as the sole or managing general partner of each
Partnership and as the sole general partner of each Nonmanaging General Partner)
to merge each Partnership with and into Pioneer USA and each such board of
directors has approved the merger of each Partnership referred to below, upon
the terms and subject to the conditions contained herein.


         E. Pioneer USA intends to solicit the vote of the limited partners of
each Partnership holding at least a majority (or with respect to Parker &
Parsley 91-A, L.P. and Parker & Parsley 91-B, L.P. (each, a "Super-Majority
Partnership"), at least 66-2/3%) of the outstanding limited partnership
interests of the Partnership to approve the merger of the Partnership. Subject
to certain limitations, upon consummation of the merger of each Partnership, the
partners, other than Pioneer USA, will have the right to receive a number of
shares of common stock, par value $0.01 per share, of Pioneer Parent (the
"Pioneer Parent Common Stock").


                                   AGREEMENTS

         NOW, THEREFORE, in consideration of the premises and the mutual
agreements contained herein, the parties hereto agree as follows:

                                    ARTICLE 1
                         THE MERGER OF EACH PARTNERSHIP

         1.1 Merger of Each Partnership. At the Effective Time (as defined in
Section 1.4), each Partnership shall be merged with and into Pioneer USA, the
separate existence of the Partnership shall cease, and Pioneer USA, as the
surviving corporation, shall continue to exist by virtue of and shall be
governed by the laws of the State of Delaware.



                                      F-2
   148


         1.2  Merger Value for Each Partnership; Pioneer Parent Common Stock
Offered.

                  (a) At the Effective Time, by virtue of the merger of each
Partnership and without any action on the part of Pioneer USA or the other
partners of the Partnership, each partnership interest outstanding immediately
prior thereto shall be converted into the right to receive an amount of Pioneer
Parent Common Stock allocated to the Partnership, which amount shall be
determined in accordance with the merger value assigned to the Partnership
pursuant to the procedures set forth herein and in the Proxy
Statement/Prospectus (as defined in Section 4.3) and the procedures set forth in
the Partnership's partnership agreement for allocating liquidation distributions
as though the assets of the Partnership were sold for the merger value of the
Partnership. The merger value for each Partnership is equal to the sum of the
present value of estimated future net revenues from the Partnership's estimated
oil and gas reserves and its net working capital, in each case as of March 31,
2001 and determined as described in the Proxy Statement/Prospectus, less its pro
rata share, based on its reserve value, of the estimated expenses and fees of
the mergers of all of the Partnerships and less the cash distribution to be
mailed on or about July 12, 2001, by the Partnership to its partners. The merger
value for each Partnership will not be adjusted as of the Closing Date. The
number of shares of Pioneer Parent Common Stock to be issued for each
partnership interest of each Partnership will be based on (i) the Partnership's
merger value divided by (ii) the average closing price of the Pioneer Parent
Common Stock, as reported by the New York Stock Exchange, for the ten trading
days ending three business days before the initial date of the special meeting
for the Partnership. For purposes of illustration in the Proxy
Statement/Prospectus, Pioneer Parent and Pioneer USA calculated the aggregate
number of shares of Pioneer Parent Common Stock to be offered based on $18.00
per share of Pioneer Parent Common Stock. Pioneer Parent and Pioneer USA shall
update the aggregate number of shares of Pioneer Parent Common Stock to be
issued based on the average closing price as described in clause (ii) above
before the date of the special meeting for each Partnership. The merger value
assigned to each Partnership and the amount of Pioneer Parent Common Stock
offered with respect to each $1,000 investment by the limited partners in the
Partnership pursuant to the merger of the Partnership are set forth in the table
entitled "Summary Table - Merger Value and Amount of Initial Limited Partner
Investment Repaid" in the Proxy Statement/Prospectus.

                  (b) All partnership interests of each Partnership, when
converted into the right to receive Pioneer Parent Common Stock, shall no longer
be outstanding and shall automatically be cancelled and retired and shall cease
to exist, and each holder of a certificate representing any such partnership
interests shall cease to have any rights with respect thereto, except the right
to receive the amount of Pioneer Parent Common Stock to be delivered in
consideration therefor.


                  (c) The partnership interests, whether general or limited, in
each Partnership held directly or indirectly by Pioneer USA shall be cancelled
without any consideration being received therefor; provided, however, that as a
result of the merger of each Partnership, Pioneer USA will own 100% of the
properties of the Partnership, including properties attributable to its
partnership interests in the Partnership.


                  (d) No fractional shares of Pioneer Parent Common Stock will
be issued. Each fractional share of Pioneer Parent Common Stock to be issued to
a partner of a Partnership will be rounded up to the nearest whole share.

                  (e) When any person has partnership interests in more than one
Partnership that merges with Pioneer USA, Pioneer USA and Pioneer Parent may, at
their sole discretion, aggregate the number of shares of Pioneer Parent Common
Stock to be issued to that person before making the rounding and other
adjustments provided in the preceding clause (d).

                  (f) If any limited partner is indebted to Pioneer USA for any
portion of the limited partner's original investment in the Partnership, Pioneer
USA plans to apply the Pioneer Parent Common Stock that would otherwise be
distributed to the limited partner upon completion of the merger of the
Partnership against that limited partner's indebtedness. If a limited partner's
indebtedness to Pioneer USA is less than the merger value allocated to limited
partnership interests held by the limited partner, the limited partner shall
receive Pioneer Parent Common Stock equal to the amount by which such merger
value exceeds such indebtedness. If a limited partner's indebtedness to Pioneer
USA is greater than the merger value allocated to the limited partnership
interests held by the limited partner, Pioneer USA may collect the deficiency
from the limited partner.




                                      F-3
   149

                  (g) To the extent that Pioneer USA or a Partnership is
required to withhold and pay over, or otherwise pay, any withholding or other
tax (the "Required Withholding") with respect to a partner or former partner in
a Partnership (the "Withholding Partner") as a result of the Withholding
Partner's current or former participation in the Partnership, Pioneer USA or the
Partnership shall be entitled to deduct and withhold (or cause to be deducted
and withheld) the Required Holding from the merger consideration (including the
Pioneer Parent Common Stock) otherwise payable to the Withholding Partner. In
the event Pioneer USA or a Partnership withholds Pioneer Parent Common Stock in
order to satisfy the Required Withholding with respect to a Withholding Partner,
Pioneer USA or the Partnership, as appropriate, may, in its sole discretion, (i)
sell such Pioneer Parent Common Stock and use the proceeds therefrom to satisfy
the Required Withholding, (ii) hold such Pioneer Parent Common Stock as security
for the satisfaction of the Required Withholding by the Withholding Partner, in
which case the Pioneer Parent Common Stock shall be released to the Withholding
Partner upon the full satisfaction of the Required Withholding by the
Withholding Partner, or (iii) take such other reasonable action as is required
or appropriate to satisfy the Required Withholding at the sole expense of the
Withholding Partner. To the extent that amounts are so withheld or deducted (or
caused to be withheld or deducted) by Pioneer USA or a Partnership, such amounts
shall be treated for all purposes of this Merger Agreement as having been paid
to the Withholding Partner.


         1.3 Closing. The closing of the merger of each Partnership (the
"Closing") shall take place at the offices of Vinson & Elkins L.L.P., 3700
Trammell Crow Center, 2001 Ross Avenue, Dallas, Texas 75201, as soon as
practicable after the fulfillment of the conditions referred to in Article 4, or
at such other time and place as the parties shall agree (the date of such
Closing being the "Closing Date").

         1.4 Effective Time of Merger of Each Partnership. Upon satisfaction of
the conditions set forth in Article 4 hereof and as soon as practicable after
the Closing, this Merger Agreement, or a certificate of merger setting forth the
information required by, and otherwise in compliance with, Section 263 of the
General Corporation Law of the State of Delaware (the "DGCL") and, if
applicable, Section 17-211 of the Revised Uniform Limited Partnership Act of the
State of Delaware (the "DRULPA") with respect to the merger of each Partnership,
shall be delivered for filing with the Secretary of State of the State of
Delaware. At such time, if applicable, a certificate of merger with respect to
the merger of each Partnership setting forth the information required by, and
otherwise in compliance with, Section 2.11 the Revised Limited Partnership Act
of the State of Texas (the "TRLPA") shall be delivered for filing with the
Secretary of State of the State of Texas. The merger of each Partnership shall
become effective upon the later of (a) the day and at the time the Secretary of
State of the State of Delaware files this Merger Agreement or such certificate
of merger in compliance with Section 263 of the DGCL and, if applicable, Section
17-211 of the DRULPA, and (b) if applicable, the day and at the time the
Secretary of State of the State of Texas files such certificate of merger in
compliance with Section 2.11 of the TRLPA (the time of such effectiveness is
herein called the "Effective Time"). Notwithstanding the foregoing, by action of
its board of directors, either Pioneer Parent or Pioneer USA, in its individual
capacity or as the sole general partner of each Partnership, may terminate this
Merger Agreement at any time prior to the earlier of (a) the filing of this
Merger Agreement or the certificate of merger with respect to the merger of the
Partnership in compliance with Section 263 of the DGCL and, if applicable,
Section 17-211 of the DRULPA with the Secretary of State of the State of
Delaware and (b) if applicable, the filing of the certificate of merger with
respect to the merger of the Partnership in compliance with Section 2.11 of the
TRLPA with Secretary of State of the State of Texas.

         1.5 Effect of Merger of Each Partnership. At the Effective Time of the
merger of each Partnership, Pioneer USA, without further action, as provided by
the laws of the State of Delaware and the State of Texas, as the case may be,
shall succeed to and possess all the rights, privileges, powers, and franchises,
of a public as well as of a private nature, of the Partnership; and all
property, real, personal and mixed, and all debts due on whatsoever account,
including subscriptions to shares, and all other choses in action, and all and
every other interest, of or belonging to or due to the Partnership shall be
deemed to be vested in Pioneer USA without further act or deed; and the title to
any real estate, or any interest therein, vested in Pioneer USA or the
Partnership shall not revert or be in any way impaired by reason of the merger
of the Partnership. Such transfer to and vesting in Pioneer USA shall be deemed
to occur by operation of law, and no consent or approval of any other person
shall be required in connection with any such transfer or vesting unless such
consent or approval is specifically required in the event of merger or
consolidation by law or express provision in any contract, agreement, decree,
order, or other instrument to which Pioneer USA or the Partnership is a party or
by which either of them is bound. At and after the Effective Time, Pioneer USA
shall be responsible and liable for all debts, liabilities, and duties of each
Partnership, including franchise taxes, if any, which may be enforced against
Pioneer USA to the same extent as if said debts, liabilities,




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and duties had been incurred or contracted by it. Neither the rights of
creditors nor any liens upon the property of any Partnership or Pioneer USA
shall be impaired by the merger of any Partnership.

         1.6 Certificate of Incorporation and Bylaws. The certificate of
incorporation of Pioneer USA before the merger of each Partnership shall be and
remain the certificate of incorporation of Pioneer USA after the Effective Time,
until the same shall thereafter be altered, amended, or repealed in accordance
with law and Pioneer USA's certificate of incorporation. The bylaws of Pioneer
USA as in effect at the Effective Time shall be and remain the bylaws of Pioneer
USA, as the surviving corporation, until the same shall thereafter be altered,
amended, or repealed in accordance with law, Pioneer USA's certificate of
incorporation or such bylaws.

         1.7 Pioneer USA Common Stock. At the Effective Time, each outstanding
share of common stock of Pioneer USA shall remain outstanding and shall continue
to represent one share of common stock of Pioneer USA.

         1.8 Officers and Directors. At the Effective Time, each of the persons
who was serving as an officer of Pioneer USA immediately prior to the Effective
Time shall continue to be an officer of Pioneer USA and shall continue to serve
in such capacity at the pleasure of the board of directors of Pioneer USA or, if
earlier, until their respective death or resignation. At the Effective Time,
each of the persons who was serving as a director of Pioneer USA immediately
prior to the Effective Time shall continue to be a director of Pioneer USA, and
each shall serve in such capacity until the next annual meeting of stockholders
of Pioneer USA and until his or her successor is elected and qualified or, if
earlier, until his death, resignation, or removal from office.

         1.9  Exchange of Partnership Interests for Pioneer Parent Common Stock.


                  (a) Continental Stock Transfer & Trust Company shall act as
the transfer and exchange agent (in such capacity, the "Transfer Agent") in
connection with the issuance of certificates representing shares of Pioneer
Parent Common Stock pursuant to Section 1.2.

                  (b) The Transfer Agent shall mail certificates representing
shares of Pioneer Parent Common Stock to the partners of record, other than
Pioneer USA, of each Partnership promptly following the Closing Date in payment
of the merger consideration. Limited partners and Nonmanaging General Partners
of each Partnership will not be required to surrender partnership interest
certificates to receive the Pioneer Parent Common Stock.

                  (c) If any certificate representing shares of Pioneer Parent
Common Stock is to be issued in a name other than that in which the limited
partnership interests cancelled in exchange therefor are registered, it shall be
a condition of the issuance thereof that the person requesting such exchange
shall pay to the Transfer Agent any transfer or other taxes required by reason
of the issuance of a certificate representing shares of Pioneer Parent Common
Stock in any name other than that of the registered holder of the cancelled
limited partnership interests, or otherwise required, or shall establish to the
satisfaction of the Transfer Agent that such tax has been paid or is not
payable.

                  (d) After the Closing Date, there shall not be any further
registration of transfers on the transfer books of any Partnership of the
partnership interests that were issued and outstanding immediately before the
Closing Date and were converted into the right to receive Pioneer Parent Common
Stock. If, after the Closing Date, certificates representing partnership
interests of a Partnership are presented, they shall be exchanged for Pioneer
Parent Common Stock, all as provided in this Article.


                                    ARTICLE 2
                         REPRESENTATIONS AND WARRANTIES


         2.1 Representations and Warranties of Each Partnership. Each
Partnership hereby represents and warrants to Pioneer Parent and Pioneer USA as
follows:


                  (a) Formation; Qualification. The Partnership is a limited
partnership duly formed under the DRULPA or TRLPA, as applicable, and is validly
existing and in good standing under the laws of the State of Delaware or the
State of Texas, as applicable. The Partnership has all requisite partnership
power and authority to own, operate or lease its properties and to carry on its
business as now being conducted. The Partnership is duly qualified to do
business as a foreign limited partnership and is in good standing in each
jurisdiction where the



                                      F-5
   151

character of its properties owned, operated or leased, or the nature of its
activities, makes such qualifications necessary.

                  (b) Capitalization. All of the outstanding partnership
interests of the Partnership are free of all liens, encumbrances, defects and
preemptive rights and are fully paid. Except as described in the Proxy
Statement/Prospectus, there are no outstanding subscriptions, options or other
arrangements or commitments obligating the Partnership to issue any additional
partnership interests.

                  (c) No Conflicts. Assuming this Merger Agreement is approved
by the requisite vote of the limited partners of the Partnership (with respect
to Parker & Parsley 85-A, Ltd., Parker & Parsley 85-B, Ltd., Parker & Parsley
Private Investment 85-A, Ltd., Parker & Parsley Selected 85 Private Investment,
Ltd., Parker & Parsley Private Investment 86, Ltd., Parker & Parsley 91-A, L.P.
and Parker & Parsley 91-B, L.P. (each, a "Special Vote Partnership"), excluding
Pioneer USA and its affiliates), consummation of the transactions contemplated
hereby and compliance with the terms and provisions of this Merger Agreement
will not conflict with, result in a breach of, require notice under or
constitute a default under (i) its certificate of limited partnership or
partnership agreement, (ii) any material judgment, order, injunction, decree or
ruling of any court or governmental authority or (iii) any material agreement,
indenture or instrument to which the Partnership is a party.

                  (d) Authority, Authorization and Enforceability. The
Partnership has all requisite power and authority to enter into and perform the
provisions of this Merger Agreement. The execution and delivery of this Merger
Agreement and the consummation of the transactions contemplated hereby have been
duly authorized by all necessary partnership action on the part of the
Partnership other than the approval of its limited partners (with respect to
each Special Vote Partnership, excluding Pioneer USA and its affiliates).
Subject to such approval, this Merger Agreement has been duly executed and
delivered by the Partnership and constitutes a valid and binding obligation of
the Partnership enforceable in accordance with its terms.

                  (e) SEC Reports; Financial Statements.

                           (i) With respect to each of Reporting Partnership (as
         defined below), the Partnership's (A) Annual Report on Form 10-K for
         the year ended December 31, 2000, (B) Quarterly Report on Form 10-Q for
         the quarter ended March 31, 2001, and (C) all other reports or
         registration statements filed with the Securities and Exchange
         Commission (the "SEC") since December 31, 2000 (collectively, the
         "Partnership's SEC Reports") (1) were prepared in accordance with the
         applicable requirements of the Securities Act of 1933 (the "Securities
         Act") and the Securities Exchange Act of 1934 (the "Exchange Act"), and
         (2) as of their respective dates, did not contain any untrue statement
         of a material fact or omit to state a material fact required to be
         stated therein or necessary in order to make the statements therein, in
         the light of the circumstances under which they are made, not
         misleading.

                           (ii) Each of the financial statements of the
         Partnership for the year ended December 31, 2000 and for the three
         months ended March 31, 2001 contained in the Partnership's supplement
         to the Proxy Statement/Prospectus and, with respect to each Reporting
         Partnership, in the Partnership's SEC Reports has been prepared in
         accordance with generally accepted accounting principles applied on a
         consistent basis throughout the periods involved (except as may be
         indicated in the notes thereto) and each fairly presents the financial
         position of the Partnership as of the respective dates thereof and the
         results of operations and cash flows of the Partnership for the periods
         indicated, except that the unaudited interim financial statements are
         subject to normal and recurring year-end adjustments that are not
         expected to be material in amount.

                           (iii) For purposes hereof, the term "Reporting
         Partnership" means: Parker & Parsley 82-I, Ltd., Parker & Parsley
         82-II, Ltd., Parker & Parsley 83-A, Ltd., Parker & Parsley 83-B, Ltd.,
         Parker & Parsley 84-A, Ltd., Parker & Parsley 85-A, Ltd., Parker &
         Parsley 85-B, Ltd., Parker & Parsley 86-A, Ltd., Parker & Parsley 86-B,
         Ltd., Parker & Parsley 86-C, Ltd., Parker & Parsley 87-A, Ltd., Parker
         & Parsley 87-B, Ltd., Parker & Parsley Producing Properties 87-A, Ltd.,
         Parker & Parsley Producing Properties 87-B, Ltd., Parker & Parsley
         88-A, L.P., Parker & Parsley 88-B, L.P., Parker & Parsley Producing
         Properties 88-A, L.P., Parker & Parsley 89-A, L.P., Parker & Parsley
         90-A L.P., Parker & Parsley 90-B Conv., L.P., Parker & Parsley 90-B,
         L.P., Parker & Parsley 90-C Conv., L.P., Parker & Parsley 90-C, L.P.,
         Parker & Parsley 91-A, L.P. and Parker & Parsley 91-B, L.P.


                                      F-6
   152

                  (f) No Material Adverse Change. Since March 31, 2001, the
Partnership has conducted its operations in the ordinary and usual course of
business and has paid all of its obligations as they have become due; and the
business of the Partnership has not undergone any material adverse change since
such date.

                  (g) Accuracy of Information. None of the information supplied
or to be supplied by the Partnership for inclusion in the Proxy
Statement/Prospectus, as amended or supplemented, will, at the time of the
mailing of the Proxy Statement/Prospectus, the time of the special meeting of
the limited partners of the Partnership (each, a "Special Meeting") or the
Closing Date, be false or misleading with respect to any material fact, contain
any untrue statement of material fact or omit to state any material fact
required to be stated therein or necessary in order to make the statements
therein, in the light of the circumstances under which they were made, not
misleading.


         2.2 Representations and Warranties of Pioneer USA. Pioneer USA hereby
represents and warrants to Pioneer Parent and each Partnership as follows:


                  (a) Organization; Qualification. Pioneer USA is a corporation
duly formed under the DGCL and is validly existing and in good standing under
the laws of the State of Delaware. Pioneer USA has all requisite corporate power
and authority to own, operate or lease its properties and to carry on its
business as now being conducted. Pioneer USA is duly qualified to do business as
a foreign corporation and is in good standing in each jurisdiction where the
character of its properties owned, operated or leased, or the nature of its
activities, makes such qualifications necessary.

                  (b) No Conflicts. Consummation of the transactions
contemplated hereby and compliance with the terms and provisions of this Merger
Agreement will not conflict with, result in a breach of, require notice under or
constitute a default under (i) its certificate of incorporation or bylaws, (ii)
any material judgment, order, injunction, decree or ruling of any court or
governmental authority or (iii) any material agreement, indenture or instrument
to which Pioneer USA is a party.

                  (c) Authority, Authorization and Enforceability. Pioneer USA
has all requisite corporate power and authority to execute and deliver this
Merger Agreement and to perform the provisions of this Merger Agreement. The
execution and delivery of this Merger Agreement and the consummation of the
transactions contemplated hereby have been duly authorized by all necessary
corporate action on the part of Pioneer USA. This Merger Agreement has been duly
executed and delivered by Pioneer USA and constitutes a valid and binding
obligation of Pioneer USA enforceable in accordance with its terms.

                  (d) No Material Adverse Change. Since March 31, 2001, Pioneer
USA has conducted its operations in the ordinary and usual course of business
and has paid all of its obligations as they have become due; and the business of
Pioneer USA has not undergone any material adverse change since such date.

                  (e) Accuracy of Information. None of the information supplied
or to be supplied by Pioneer USA for inclusion in the Proxy
Statement/Prospectus, as amended or supplemented, will, at the time of the
mailing of the Proxy Statement/Prospectus, the time of the Special Meeting of
each Partnership or the Closing Date, be false or misleading with respect to any
material fact, contain any untrue statement of material fact or omit to state
any material fact required to be stated therein or necessary in order to make
the statements therein, in the light of the circumstances under which they were
made, not misleading.

                  (f) Capacity as General Partner. Pioneer USA is the sole or
managing general partner of each Partnership and is the sole general partner of
each Nonmanaging General Partner.


         2.3 Representations and Warranties of Pioneer Parent. Pioneer Parent
hereby represents and warrants to Pioneer USA and each Partnership as follows:

                  (a) Organization; Qualification. Pioneer Parent is a
corporation duly formed under the DGCL and is validly existing and in good
standing under the laws of the State of Delaware. Pioneer Parent has all
requisite corporate power and authority to own, operate or lease its properties
and to carry on its business as now being conducted. Pioneer Parent is duly
qualified to do business as a foreign corporation and is in good standing in
each jurisdiction where the character of its properties owned, operated or
leased, or the nature of its activities, makes such qualifications necessary.




                                      F-7
   153


                  (b) No Conflicts. Consummation of the transactions
contemplated hereby and compliance with the terms and provisions of this Merger
Agreement will not conflict with, result in a breach of, require notice under or
constitute a default under (i) its certificate of incorporation or bylaws, (ii)
any material judgment, order, injunction, decree or ruling of any court or
governmental authority or (iii) any material agreement, indenture or instrument
to which Pioneer Parent is a party.

                  (c) Authority, Authorization and Enforceability. Pioneer
Parent has all requisite corporate power and authority to execute and deliver
this Merger Agreement and to perform the provisions of this Merger Agreement.
The execution and delivery of this Merger Agreement and the consummation of the
transactions contemplated hereby have been duly authorized by all necessary
corporate action on the part of Pioneer Parent. This Merger Agreement has been
duly executed and delivered by Pioneer Parent and constitutes a valid and
binding obligation of Pioneer Parent enforceable in accordance with its terms.
When issued in accordance with this Merger Agreement, the shares of Pioneer
Parent Common Stock will be validly issued, fully paid and nonassessable and not
subject to preemptive rights.


                  (d) SEC Reports; Financial Statements.


                           (i) Pioneer Parent's (A) Annual Report on Form 10-K
         for the year ended December 31, 2000, (B) Quarterly Report on Form 10-Q
         for the quarter ended March 31, 2001, and (C) all other reports or
         registration statements filed with the SEC since December 31, 2000
         (collectively, "Pioneer Parent's SEC Reports") (1) were prepared in
         accordance with the applicable requirements of the Securities Act and
         the Exchange Act, and (2) as of their respective dates, did not contain
         any untrue statement of a material fact or omit to state a material
         fact required to be stated therein or necessary in order to make the
         statements therein, in the light of the circumstances under which they
         are made, not misleading.

                           (ii)Each of the financial statements of Pioneer
         Parent for the year ended December 31, 2000 and for the three months
         ended March 31, 2001 contained in Pioneer Parent's SEC Reports has been
         prepared in accordance with generally accepted accounting principles
         applied on a consistent basis throughout the periods involved (except
         as may be indicated in the notes thereto) and each fairly presents the
         financial position of Pioneer Parent as of the respective dates thereof
         and the results of operations and cash flows of Pioneer Parent for the
         periods indicated, except that the unaudited interim financial
         statements are subject to normal and recurring year-end adjustments
         that are not expected to be material in amount.

                  (e) No Material Adverse Change. Since March 31, 2001, Pioneer
Parent has conducted its operations in the ordinary and usual course of business
and has paid all of its obligations as they have become due; and the business of
Pioneer Parent has not undergone any material adverse change since such date.


                  (f) Accuracy of Information. None of the information supplied
or to be supplied by Pioneer Parent for inclusion in the Proxy
Statement/Prospectus, as amended or supplemented, will, at the time of the
mailing of the Proxy Statement/Prospectus, the time of the Special Meeting of
each Partnership or the Closing Date, be false or misleading with respect to any
material fact, contain any untrue statement of material fact or omit to state
any material fact required to be stated therein or necessary in order to make
the statements therein, in the light of the circumstances under which they were
made, not misleading.

                                    ARTICLE 3
             CONDITIONS PRECEDENT TO THE MERGER OF EACH PARTNERSHIP

         3.1 Conditions to Each Party's Obligations to Effect the Merger of Each
Partnership. The respective obligations of each party to effect the merger of
each Partnership shall be subject to the fulfillment (or waiver in whole or in
part by the intended beneficiary thereof in its sole discretion) at or prior to
the Closing Date of the following conditions:

                  (a) This Merger Agreement, an amendment to the partnership
agreement of each Partnership to permit the merger of such Partnership (the
"Merger Amendment"), the selection of special counsel for the limited partners
and that counsel's legal opinion referred to in Section 3.1(c) shall have been
approved by the limited partners (with respect to each Special Vote Partnership,
excluding Pioneer USA and its affiliates) holding at least a



                                      F-8
   154
 majority (or, with respect to each Super-Majority Partnership, at least
66-2/3%) of the outstanding limited partnership interests voting in person or by
proxy at the Special Meetings at which a quorum is present, with respect to each
merger.

                  (b) Pioneer USA shall have received from Robert A. Stanger &
Co., Inc. a written opinion for inclusion in the Proxy Statement/Prospectus
satisfactory in form and substance to Pioneer USA and substantially to the
effect that, as of the date of that opinion, the merger value for each
Partnership and the allocation of the merger value of the Partnership (1) to the
limited partners of the Partnership as a group, (2) to the general partners of
the Partnership as a group, (3) to Pioneer USA as the managing or sole general
partner of the Partnership, (4) to the unaffiliated limited partners of the
Partnership as a group and (5) to the unaffiliated limited partners of the
Nonmanaging General Partner, if any, of the Partnership as a group, is fair to
the unaffiliated limited partners of the Partnership and the unaffiliated
limited partners of the Nonmanaging General Partner, if any, of the Partnership,
from a financial point of view. Such opinion shall not have been withdrawn prior
to the Closing Date, unless a replacement opinion or opinions of an investment
banking firm or firms satisfactory to Pioneer USA to a similar effect has been
received by Pioneer USA and has not been withdrawn.

                  (c) The receipt, on or prior to the Closing Date, by Pioneer
USA of the opinion of special legal counsel for the limited partners pursuant to
the partnership agreement of each Partnership.

                  (d) No provision of any applicable law or regulation and no
judgment, injunction, order or decree shall prohibit the consummation of the
merger of any Partnership and the transactions related thereto.


                  (e) No suit, action or proceeding shall have been filed or
otherwise be pending against Pioneer Parent, Pioneer USA or any officer,
director or affiliate of Pioneer Parent or Pioneer USA challenging the legality
or any aspect of the merger of any Partnership or the transactions related
thereto.

                  (f) The shares of Pioneer Parent Common Stock issuable upon
the merger of each Partnership pursuant to this Merger Agreement shall have been
authorized for listing on the New York Stock Exchange and the Toronto Stock
Exchange upon official notice of issuance.

                  (g) The parties to the merger of each Partnership having made
all filings and registrations with, and notifications to, all third parties,
including, without limitation, lenders and all appropriate regulatory
authorities, required for consummation of the transactions contemplated by this
Merger Agreement (other than the filing and recordation of appropriate merger
documents required by the DGCL, the DRULPA and the TRLPA, as applicable), and
all approvals and authorizations and consents of all third parties, including,
without limitation, lenders and all regulatory authorities, required for
consummation of the transactions contemplated by this Merger Agreement shall
have been received and shall be in full force and effect, except for such
filings, registrations, notifications, approvals, authorizations and consents,
the failure of which to make or obtain would not have a material adverse effect
on the business or financial condition of Pioneer Parent, Pioneer USA or any
Partnership.


                  (h) The absence of any opinion of counsel that the exercise by
the limited partners of any Partnership of the right to approve the merger of
such Partnership is not permitted under applicable state law.


         3.2 Conditions to Obligations of Pioneer Parent to Effect the Merger of
Each Partnership. The obligations of Pioneer Parent to effect the merger of each
Partnership shall be subject to the fulfillment (or waiver in whole or in part
by the intended beneficiary thereof in its sole discretion), at or prior to the
Closing Date, of the following additional conditions:


                  (a) Pioneer USA and each Partnership shall have performed in
all material respects their respective agreements contained in this Merger
Agreement required to be performed at or prior to the Closing Date.

                  (b) The representations and warranties of Pioneer USA and each
Partnership contained in this Merger Agreement shall be true and correct in all
material respects at and as of the Closing Date as if made at and as of such
time unless they relate to another specified time.

         3.3 Conditions to Obligations of Pioneer USA and Each Partnership to
Effect the Merger of Such Partnership. The obligations of Pioneer USA and each
Partnership to effect the merger of such Partnership shall be




                                      F-9
   155

subject to the fulfillment (or waiver in whole or in part by the intended
beneficiary thereof in its sole discretion) at or prior to the Closing Date of
the following additional conditions:


                  (a) Pioneer Parent shall have performed in all material
respects its agreements contained in this Merger Agreement required to be
performed at or prior to the Closing Date.

                  (b) The representations and warranties of Pioneer Parent
contained in this Merger Agreement shall be true and correct in all material
respects at and as of the Closing Date as if made at and as of such time unless
they relate to another specific time.


                                    ARTICLE 4
                              ADDITIONAL AGREEMENTS

         4.1 Conduct of Business Pending the Merger of Each Partnership. Each
Partnership covenants and agrees that, between the date of this Merger Agreement
and the Closing Date, unless the other parties shall otherwise agree in writing
or as otherwise contemplated in this Merger Agreement, it shall conduct its
businesses only in the ordinary course of business and in a manner consistent
with past practice, and it shall not take any action except for actions
consistent with such practice. Each Partnership shall use its reasonable best
efforts to preserve intact its business organization, to keep available the
services of its present officers, employees and consultants, and to preserve its
relationships with customers, suppliers and other persons with which it has
significant business dealings.

         4.2 Special Meetings; Proxies. As soon as reasonably practicable after
the execution of this Merger Agreement, Pioneer USA will take all action
necessary to duly call, give notice of, convene and hold the Special Meetings to
consider and vote upon approval of this Merger Agreement, the Merger Amendment,
the selection of special legal counsel for the limited partners, that counsel's
legal opinion referred to in Section 3.1(c) and the transactions contemplated
hereby and thereby. Pioneer USA will use its reasonable best efforts to solicit
from the limited partners proxies in favor of this Merger Agreement, the Merger
Amendment, the selection of special legal counsel for the limited partners, that
counsel's legal opinion referred to in Section 3.1(c) and the transactions
contemplated hereby and thereby, and to take all other action necessary or
advisable to secure any vote or consent of the limited partners of each
Partnership required by the partnership agreement of the Partnership or this
Merger Agreement or applicable law to effect the merger of the Partnership.


         4.3 Proxy Statement/Prospectus. Pioneer Parent and Pioneer USA shall
file with the SEC a registration statement that includes a preliminary proxy
statement/prospectus for each Special Meeting (the definitive form of such proxy
statement/prospectus is referred to as the "Proxy Statement/Prospectus").
Pioneer Parent and Pioneer USA shall use all reasonable commercial efforts to
have the registration statement declared effective by the SEC as promptly as
practicable. Pioneer Parent and Pioneer USA shall cause the Proxy
Statement/Prospectus to be mailed to the limited partners of each Partnership as
soon as practicable thereafter in accordance with applicable federal and state
law.

         4.4 Authorization for Shares and Stock Exchange Listing. Prior to the
Effective Time, Pioneer Parent and Pioneer USA shall have taken all action
necessary to permit Pioneer Parent to issue the number of shares of Pioneer
Parent Common Stock required to be issued pursuant to this Merger Agreement.
Each of Pioneer Parent and Pioneer USA shall use its commercially reasonable
efforts to cause the shares of Pioneer Parent Common Stock to be issued in the
merger of each Partnership to be approved for listing on the New York Stock
Exchange and the Toronto Stock Exchange, subject to official notice of issuance,
prior to the Closing Date.


         4.5 Additional Agreements. Subject to the terms and conditions herein
provided, each of the parties hereto agrees to use all reasonable commercial
efforts to obtain in a timely manner all necessary waivers, consents and
approvals and to effect all necessary registrations and filings, and to use all
reasonable commercial efforts to take, or cause to be taken, all other actions
and to do, or cause to be done, all other things necessary, proper or advisable
under applicable laws and regulations to consummate and make effective as
promptly as practicable the transactions contemplated by this Merger Agreement.



                                      F-10
   156

                                    ARTICLE 5
                                   TERMINATION

         5.1 Termination. This Merger Agreement may be terminated and the merger
of any Partnership contemplated hereby may be abandoned, in whole or in part, at
any time prior to the Effective Time, whether before or after approval of the
merger of the Partnership by its limited partners (with respect to each Special
Vote Partnership, excluding Pioneer USA and its affiliates):

                  (a) By mutual written consent of the parties;

                  (b) By any party, if:

                           (i) there shall be any applicable law, rule or
         regulation that makes consummation of the merger of any Partnership
         illegal or otherwise prohibited or if any judgment, injunction, order
         or decree enjoining any party from consummating the merger of any
         Partnership is entered and such judgment, injunction, order or decree
         shall have become final and non-appealable;

                           (ii)at the Special Meeting of each Partnership or at
         any adjournment or postponement thereof, the approval of the limited
         partners of the Partnership referred to in Section 3.1(a) shall not
         have been obtained by reason of the failure to obtain the requisite
         vote; or


                           (iii) there shall be any pending suit, action or
         proceeding filed against Pioneer Parent, Pioneer USA, any Partnership
         or any officer, director or affiliate of Pioneer Parent or Pioneer USA
         challenging the legality or any aspect of the merger of any Partnership
         or the transactions related thereto;

                  (c) By Pioneer Parent, if either Pioneer USA or any
Partnership shall have failed to perform its agreements and covenants contained
herein, which failure has a material adverse effect on Pioneer USA or such
Partnership, as the case may be, or materially and adversely affects the
transactions contemplated by this Merger Agreement;


                  (d) By Pioneer USA or any Partnership with respect to the
Partnership's merger, if Pioneer Parent shall have failed to perform its
agreements and covenants contained herein, which failure has a material adverse
effect on Pioneer USA or such Partnership, as the case may be, or materially and
adversely affects the transactions contemplated by this Merger Agreement;


                  (e) By Pioneer Parent or Pioneer USA, pursuant to Section 1.4
hereof;


                  (f) By Pioneer USA, if Pioneer USA, after considering the
written advice of outside legal counsel, determines in good faith that
termination of this Merger Agreement is required for Pioneer USA's board of
directors to comply with its fiduciary duties to its sole stockholder or to any
Partnership imposed by applicable law; or


                  (g) By Pioneer Parent, if there shall have occurred any event,
circumstance, condition, development or occurrence causing, resulting in or
having, or reasonably expected to cause, result in or have, a material adverse
effect (i) on any Partnership's business, operations, properties (taken as a
whole), condition (financial or otherwise), results of operations, assets (taken
as a whole), liabilities, cash flows or prospects, (ii) on market prices for oil
and gas prevailing generally in the oil and gas industry since the date of
determination of the oil and gas commodity prices used in the determination of
the merger value for each Partnership, (iii) on the price of Pioneer Parent
Common Stock or (iv) on the oil and gas industry generally.


         5.2 Effect of Termination. In the event of termination of this Merger
Agreement by a party as provided in Section 5.1, written notice thereof shall
promptly be given to the other parties and this Merger Agreement shall forthwith
terminate without further action by any of the parties hereto. If this Merger
Agreement is terminated as so provided, there shall be no liabilities or
obligations hereunder on the part of any party hereto except as provided in
Section 6.13 and except that nothing herein shall relieve any party hereto from
liability for any breach of this Merger Agreement.



                                      F-11
   157

                                    ARTICLE 6
                                  MISCELLANEOUS

         6.1 Headings. The headings contained in this Merger Agreement are for
reference purposes only and shall not affect in any way the meaning or
interpretation of this Merger Agreement.


         6.2 Amendment. This Merger Agreement may be supplemented, amended or
modified by an instrument in writing signed by Pioneer Parent and Pioneer USA
(on behalf of itself and as (a) the sole or managing general partner of each
Partnership, (b) the sole general partner of each Nonmanaging General Partner
and (c) attorney-in-fact for the limited partners of each Partnership) at any
time prior to the Closing Date; provided, however, that after approval by the
limited partners of each Partnership (with respect to each Special Vote
Partnership, excluding Pioneer USA and its affiliates) of this Merger Agreement,
the Merger Amendment, the selection of special legal counsel for the limited
partners and that counsel's legal opinion referred to in Section 3.1(c), no
amendment may be made which would adversely change the type or amount of, or the
method for determining, the consideration to be received upon consummation of
the merger of each Partnership or which would in any other way materially and
adversely affect the rights of such limited partners (other than a termination
of this Merger Agreement or abandonment of the merger of any Partnership).


         6.3 Waiver. At any time prior to the Closing Date, the parties hereto
may (a) extend the time for the performance of any of the obligations or other
acts of the other parties hereto, (b) waive any inaccuracies in the
representations and warranties contained herein or in any document delivered
pursuant hereto, and (c) waive compliance with any of the agreements or
conditions contained herein. Any such extension or waiver shall not operate as
an extension or waiver of, or estoppel with respect to, any subsequent failure
of compliance or other failure. Any agreement on the part of a party hereto to
any such extension or waiver shall be valid against such party if set forth in
an instrument in writing signed by such party.

         6.4 Expiration of Representations and Warranties. All representations
and warranties made pursuant to this Merger Agreement shall expire with, and be
terminated and extinguished by, the merger of each Partnership on the Closing
Date.


         6.5 Notices. All notices and other communications to be given or made
hereunder by any party shall be delivered by first class mail, or by personal
delivery, postage or fees prepaid, (a) to Pioneer Parent at 1400 Williams Square
West, 5205 North O'Connor Boulevard, Irving, Texas 75039, Attn: Scott D.
Sheffield, with a copy to Vinson & Elkins L.L.P., 3700 Trammell Crow Center,
2001 Ross Avenue, Dallas, Texas 75201, Attn: Robert L. Kimball, and (b) to the
other parties at Pioneer Natural Resources USA, Inc., 1400 Williams Square West,
5205 North O'Connor Boulevard, Irving, Texas 75039, Attn: Mark L. Withrow, with
a copy to Sayles, Lidji & Werbner, 4400 Renaissance Tower, 1201 Elm Street,
Dallas, Texas 75270, Attn: Brian M. Lidji.


         6.6 Counterparts. This Merger Agreement may be executed in one or more
counterparts, each of which shall be deemed an original, but all of which
together shall constitute one and the same agreement.

         6.7 Severability. If any term or other provision of this Merger
Agreement is invalid, illegal or incapable of being enforced by any rule of law
or public policy, all other conditions and provisions of this Merger Agreement
shall nevertheless remain in full force and effect so long as the economic or
legal substance of the transactions contemplated hereby is not affected in any
manner materially adverse to any party.

         6.8 Entire Agreement. This Merger Agreement, including the documents
and instruments referred to herein, constitutes the entire agreement and
supersedes all other prior agreements and undertakings, both written and oral,
between the parties, or any of them, with respect to the subject matter hereof.

         6.9 Remedies. Except as otherwise expressly provided herein, this
Merger Agreement is not intended to confer upon any other person any rights or
remedies hereunder.

         6.10 Assignment. This Merger Agreement shall not be assigned by
operation of law or otherwise without the consent of all parties hereto.


                                      F-12
   158
         6.11 No Implied Waiver. Except as expressly provided in this Merger
Agreement, no course of dealing among the parties hereto and no delay by any of
them in exercising any right, power or remedy conferred herein or now or
hereafter existing at law or in equity, by statute or otherwise, shall operate
as a waiver of, or otherwise prejudice, any such right, power or remedy.

         6.12 Governing Law. Except to the extent that TRLPA is mandatorily
applicable, this Merger Agreement shall be governed by, and construed in
accordance with, the laws of the State of Delaware (regardless of the laws that
might otherwise govern under applicable principles of conflicts of law) as to
all matters.


         6.13 Expenses. Except as otherwise provided herein, to the extent the
merger of a Partnership is completed, that participating Partnership shall pay
its pro rata share, based on its reserve value, of the aggregate estimated
expenses and fees to be incurred in connection with the merger of each
Partnership with and into Pioneer USA. Except as otherwise provided herein, to
the extent the merger of a Partnership is not completed, that nonparticipating
Partnership shall pay a portion of the estimated expenses and fees of the
mergers otherwise allocable to the Partnership based on a fraction, the
numerator of which is the percentage of the Partnership's limited partnership
interests that are voted in favor of the merger proposals and the denominator of
which is the percentage of the Partnership's limited partnership interests for
which votes are cast. Pioneer Parent shall pay (a) the remainder of the
estimated expenses and fees otherwise allocable to any such nonparticipating
Partnership and (2) any expenses and fees actually incurred in excess of $2.0
million. In addition, if Pioneer Parent terminates this Merger Agreement or
abandons the merger of any Partnership pursuant to Section 5.1, Pioneer Parent
shall pay all estimated expenses and fees of such Partnership incurred in
connection with the merger of such Partnership before such termination or
abandonment.

         6.14 Liquidation. Each Partnership, Pioneer Parent and Pioneer USA
intend and agree that the merger of each Partnership shall be treated as a
liquidation of the Partnership into Pioneer USA pursuant to Section 332 of the
Internal Revenue Code of 1986, as amended, and shall make all declarations and
filings necessary to accomplish such intent and liquidation.


                            [Signature pages follow.]




                                      F-13
   159
         IN WITNESS WHEREOF, each of the parties hereto has executed this Merger
Agreement as of the date first written above.


                           
                              PIONEER NATURAL RESOURCES COMPANY


                              By:
                                 ---------------------------------------------------------
                              Name:
                                   -------------------------------------------------------
                              Title:
                                    ------------------------------------------------------


                              PIONEER NATURAL RESOURCES USA, INC.


                              By:
                                   -------------------------------------------------------
                                   Mark L. Withrow
                                   Executive Vice President, General Counsel and Secretary


                              PARTNERSHIPS:

                              Parker & Parsley 81-I, Ltd.
                              Parker & Parsley 81-II, Ltd.
                              Parker & Parsley 82-I, Ltd.
                              Parker & Parsley 82-II, Ltd.
                              Parker & Parsley 82-III, Ltd.
                              Parker & Parsley 83-A, Ltd.
                              Parker & Parsley 83-B, Ltd.
                              Parker & Parsley 84-A, Ltd.
                              Parker & Parsley 85-A, Ltd.
                              Parker & Parsley 85-B, Ltd.
                              Parker & Parsley Private Investment 85-A, Ltd.
                              Parker & Parsley Selected 85 Private Investment, Ltd.
                              Parker & Parsley 86-A, Ltd.
                              Parker & Parsley 86-B, Ltd.
                              Parker & Parsley 86-C, Ltd.
                              Parker & Parsley Private Investment 86, Ltd.
                              Parker & Parsley 87-A Conv., Ltd.
                              Parker & Parsley 87-A , Ltd.
                              Parker & Parsley 87-B Conv., Ltd.
                              Parker & Parsley 87-B, Ltd.
                              Parker & Parsley Producing Properties 87-A, Ltd.
                              Parker & Parsley Producing Properties 87-B, Ltd.
                              Parker & Parsley Private Investment 87, Ltd.
                              Parker & Parsley 88-A Conv., L.P.
                              Parker & Parsley 88-A, L.P.
                              Parker & Parsley 88-B Conv., L.P.
                              Parker & Parsley 88-B, L.P.
                              Parker & Parsley 88-C Conv., L.P.
                              Parker & Parsley 88-C, L.P.
                              Parker & Parsley Producing Properties 88-A, L.P.
                              Parker & Parsley Private Investment 88, L.P.
                              Parker & Parsley 89-A Conv., L.P.
                              Parker & Parsley 89-A, L.P.
                              Parker & Parsley 89-B Conv., L.P.
                              Parker & Parsley 89-B, L.P.
                              Parker & Parsley Private Investment 89, L.P.




                                      F-14
   160


                           
                              Parker & Parsley 90-A Conv., L.P.
                              Parker & Parsley 90-A, L.P.
                              Parker & Parsley 90-B Conv., L.P.
                              Parker & Parsley 90-B, L.P.
                              Parker & Parsley 90-C Conv., L.P.
                              Parker & Parsley 90-C, L.P.
                              Parker & Parsley Private Investment 90, L.P.
                              Parker & Parsley 90 Spraberry Private Development, L.P.
                              Parker & Parsley 91-A, L.P.
                              Parker & Parsley 91-B, L.P.

                              By:  Pioneer  Natural  Resources  USA,  Inc.,  as the sole or
                                   managing  general partner of each Partnership


                              By:
                                   -------------------------------------------------------
                                   Mark L. Withrow
                                   Executive Vice President, General Counsel and Secretary


                              By:  Pioneer  Natural  Resources USA, Inc., as the sole general
                                   partner of each Nonmanaging General Partner


                              By:
                                   -------------------------------------------------------
                                   Mark L. Withrow
                                   Executive Vice President, General Counsel and Secretary


                              By:  Pioneer Natural  Resources USA, Inc., as  attorney-in-fact
                                   for the limited partners of each Partnership


                              By:
                                   -------------------------------------------------------
                                   Mark L. Withrow
                                   Executive Vice President, General Counsel and Secretary





                                      F-15
   161

                        PIONEER NATURAL RESOURCES COMPANY
                       PIONEER NATURAL RESOURCES USA, INC.
                            1400 WILLIAMS SQUARE WEST
                            5205 NORTH O'CONNOR BLVD.
                               IRVING, TEXAS 75039

                            SUPPLEMENTAL INFORMATION

                                       OF

            PARKER & PARSLEY 81-I, LTD., A TEXAS LIMITED PARTNERSHIP

                                       TO

              PROXY STATEMENT/PROSPECTUS DATED            , 2001

                                   ----------

                THE DATE OF THIS SUPPLEMENT IS         , 2001

                                   ----------


         This document contains important information specific to Parker &
Parsley 81-I, Ltd. and supplements the proxy statement/prospectus dated        ,
2001, of Pioneer Natural Resources Company and Pioneer Natural Resources USA,
Inc., by which Pioneer USA is soliciting proxies to be voted at a special
meeting of limited partners of the partnership. The purpose of the special
meeting is for you to vote upon the merger of the partnership with and into
Pioneer USA that, if completed, will result in your receiving common stock of
Pioneer Natural Resources Company for your partnership interests.


         This document contains the following information concerning Parker &
Parsley 81-I, Ltd.:

         o A table containing:

           - the aggregate initial investment by the limited partners


           - the aggregate historical limited partner distributions through July
             31, 2001

           - the merger value attributable to partnership interests of limited
             partners, excluding Pioneer USA

           - the merger value per $1,000 limited partner investment

           - the merger value per $1,000 limited partner investment as a
             multiple of distributions for the past four quarterly distributions
             including the distribution in July 2001


           - the book value per $1,000 limited partner investment as of
             March 31, 2001 and as of December 31, 2000


           - the going concern value per $1,000 limited partner investment

           - the liquidation value per $1,000 limited partner investment


           - the ordinary tax loss per $1,000 limited partner investment in year
             of initial investment

         o Information about:


           - the legal opinion for the limited partners

           - the term of the partnership


         o The partnership's financial statements, including management's
           discussion and analysis of financial condition and results of
           operations, for the three months ended March 31, 2001

         o The partnership's financial statements, including management's
           discussion and analysis of financial condition and results of
           operations, for the year ended December 31, 2000

         o Selected historical financial data for the partnership for the three
           months ended March 31, 2001 and 2000 and the five years ended
           December 31, 2000


                                      -1-
   162


                           PARKER & PARSLEY 81-I, LTD.

                         SUPPLEMENTAL INFORMATION TABLE


                                                                                                         
Aggregate Initial Investment by the Limited Partners(a)                                                      $      7,410

Aggregate Historical Limited Partner Distributions through July 31, 2001(a)                                  $      4,869

Merger Value Attributable to Partnership Interests of Limited Partners, Excluding Pioneer USA(a), (b)        $        629

Merger Value per $1,000 Limited Partner Investment(b), (c)                                                   $      90.13

Merger Value per $1,000 Limited Partner Investment as a Multiple of Distributions for                                3.50 times
the past four quarterly distributions including the distribution in July 2001(b), (c)

Book Value per $1,000 Limited Partner Investment:

      --    as of March 31, 2001(c)                                                                          $      19.17

      --    as of December 31, 2000(c)                                                                       $      20.30

Going Concern Value per $1,000 Limited Partner Investment(c), (d)                                            $      81.97

Liquidation Value per $1,000 Limited Partner Investment(c), (e)                                              $      87.44

Ordinary Tax Loss per $1,000 Limited Partner Investment in Year of Initial Investment(c), (f)                $        320



----------

(a)      Stated in thousands.


(b)      The merger value for the partnership is equal to the sum of the present
         value of estimated future net revenues from the partnership's estimated
         oil and gas reserves and its net working capital, in each case as of
         March 31, 2001, less its pro rata share, based on its reserve value, of
         the estimated expenses and fees of the mergers of all of the
         partnerships and less the cash distribution on or about July 9, 2001,
         by the partnership to its partners.

(c)      Interests in some partnerships were sold in units at prices other than
         $1,000. We have presented this information based on a $1,000 initial
         investment for ease of use and comparison among partnerships. You
         should not assume that the amount shown per $1,000 investment is the
         same as the value or amount attributable to a single unit investment.

(d)      The going concern value for the partnership is based upon: (1) the sum
         of (A) the estimated net cash flow from the sale of the partnership's
         reserves during a 10-year operating period and (B) the estimated
         residual value from the sale of the partnership's remaining reserves at
         the end of the operating period, in each case using the same pricing
         and discount rate as in the merger value calculation, less (2)
         partnership level general and administrative expenses.

(e)      The liquidation value for the partnership is based upon the sale of the
         partnership's reserves at the reserve value, less liquidation expenses
         which are estimated to be the sum of (1) the partnership's pro rata
         share of the merger expenses and fees described in footnote (b) above
         and (2) 3% of the partnership's reserve value. The liquidation expenses
         represent the estimated costs to retain an investment banker or broker
         to sell the assets of the partnership and the legal and other closing
         costs associated with such transaction, including the wind-down costs
         of the partnership.

(f)      Your ability to use your distributive share of the partnership's loss
         to offset your other income may have been subject to certain
         limitations at your level as a partner, and you may therefore wish to
         consult your tax advisor to determine the additional value, if any,
         actually realized by you in your particular circumstances.


          INFORMATION ABOUT THE LEGAL OPINION FOR THE LIMITED PARTNERS

         The partnership agreement for the partnership requires that special
legal counsel render an opinion on behalf of the limited partners to Pioneer USA
that (1) neither the grant nor the exercise of the right to approve the merger
of the partnership by its limited partners will adversely affect the federal
income tax classification of the partnership or any of its limited partners; and
(2) neither the grant nor exercise of such right will result in the loss of any
limited partner's limited liability. In addition, the counsel designated to
render the opinion must be counsel other than counsel to Pioneer USA or the
partnership. Both the designated counsel and the legal opinion must be approved
by the limited partners. Pioneer USA has retained __________ of Dallas, Texas
for the purpose of rendering this legal opinion on behalf of the limited
partners to Pioneer USA. The merger proposals include an approval of that
counsel and the form of its opinion. A copy of the opinion is attached as an
exhibit to the merger proposals.


                  INFORMATION ABOUT THE TERM OF THE PARTNERSHIP

         The term of the partnership shall continue until terminated in
accordance with the applicable provisions of its partnership agreement.






                                      -2-

   163


                           PARKER & PARSLEY 81-I, LTD.

                          (A Texas Limited Partnership)


                              FINANCIAL STATEMENTS

                                 March 31, 2001


   164



                           PARKER & PARSLEY 81-I, LTD.
                          (A Texas Limited Partnership)

                                 BALANCE SHEETS





                                                      March 31,     December 31,
                                                        2001           2000
                                                    ------------    ------------
                                                    (Unaudited)
                                                              
                   ASSETS

Current assets:
  Cash                                              $     37,628    $     38,546
  Accounts receivable - oil and gas sales                 55,070          63,269
                                                    ------------    ------------
        Total current assets                              92,698         101,815
                                                    ------------    ------------
Oil and gas properties - at cost, based on the
  successful efforts accounting method                 5,245,898       5,245,144
Accumulated depletion                                 (5,144,081)     (5,142,190)
                                                    ------------    ------------
        Net oil and gas properties                       101,817         102,954
                                                    ------------    ------------
                                                    $    194,515    $    204,769
                                                    ============    ============

LIABILITIES AND PARTNERS' CAPITAL

Current liabilities:
  Accounts payable - affiliate                      $      9,796    $      8,817

Partners' capital:
  General partners                                        42,670          45,564
  Limited partners (1,482 interests)                     142,049         150,388
                                                    ------------    ------------
                                                         184,719         195,952
                                                    ------------    ------------
                                                    $    194,515    $    204,769
                                                    ============    ============


  The financial information included as of March 31, 2001 has been prepared by
  the managing general partner without audit by independent public accountants.

   The accompanying notes are an integral part of these financial statements.



                                        2

   165



                           PARKER & PARSLEY 81-I, LTD.
                          (A Texas Limited Partnership)

                            STATEMENTS OF OPERATIONS
                                   (Unaudited)





                                                     Three months ended
                                                          March 31,
                                                   -----------------------
                                                      2001         2000
                                                   ----------   ----------
                                                          
Revenues:
  Oil and gas                                      $  108,191   $   94,181
  Interest                                                719          563
                                                   ----------   ----------
                                                      108,910       94,744
                                                   ----------   ----------
Costs and expenses:
  Oil and gas production                               44,964       40,666
  General and administrative                            4,857        2,921
  Depletion                                             1,891        1,618
                                                   ----------   ----------
                                                       51,712       45,205
                                                   ----------   ----------
Net income                                         $   57,198   $   49,539
                                                   ==========   ==========
Allocation of net income:
  General partners                                 $   14,328   $   12,628
                                                   ==========   ==========
  Limited partners                                 $   42,870   $   36,911
                                                   ==========   ==========
Net income per limited partnership interest        $    28.93   $    24.91
                                                   ==========   ==========




         The financial information included herein has been prepared by the
managing general partner without audit by independent public accountants.

   The accompanying notes are an integral part of these financial statements.



                                        3
   166



                           PARKER & PARSLEY 81-I, LTD.
                          (A Texas Limited Partnership)

                         STATEMENT OF PARTNERS' CAPITAL
                                   (Unaudited)




                                   General         Limited
                                   partners        partners         Total
                                 ------------    ------------    ------------
                                                        

Balance at January 1, 2001       $     45,564    $    150,388    $    195,952

    Distributions                     (17,222)        (51,209)        (68,431)

    Net income                         14,328          42,870          57,198
                                 ------------    ------------    ------------

Balance at March 31, 2001        $     42,670    $    142,049    $    184,719
                                 ============    ============    ============





         The financial information included herein has been prepared by the
managing general partner without audit by independent public accountants.

   The accompanying notes are an integral part of these financial statements.



                                        4

   167



                           PARKER & PARSLEY 81-I, LTD.
                          (A Texas Limited Partnership)

                            STATEMENTS OF CASH FLOWS
                                   (Unaudited)





                                                          Three months ended
                                                               March 31,
                                                       ------------------------
                                                          2001          2000
                                                       ----------    ----------
                                                               
Cash flows from operating activities:
  Net income                                           $   57,198    $   49,539
  Adjustments to reconcile net income to net
    cash provided by operating activities:
       Depletion                                            1,891         1,618
  Changes in assets and liabilities:
       Accounts receivable                                  8,199        (6,807)
       Accounts payable                                       979          (173)
                                                       ----------    ----------
         Net cash provided by operating activities         68,267        44,177
                                                       ----------    ----------
Cash flows used in investing activities:
  Additions to oil and gas properties                        (754)         (110)

Cash flows used in financing activities:
  Cash distributions to partners                          (68,431)      (41,860)
                                                       ----------    ----------
Net increase (decrease) in cash                              (918)        2,207
Cash at beginning of period                                38,546        38,716
                                                       ----------    ----------
Cash at end of period                                  $   37,628    $   40,923
                                                       ==========    ==========




         The financial information included herein has been prepared by the
managing general partner without audit by independent public accountants.

   The accompanying notes are an integral part of these financial statements.




                                        5
   168



                           PARKER & PARSLEY 81-I, LTD.
                          (A Texas Limited Partnership)

                          NOTES TO FINANCIAL STATEMENTS
                                 March 31, 2001
                                   (Unaudited)

Note 1.     Organization and nature of operations

Parker & Parsley 81-I, Ltd. (the "Partnership") is a limited partnership
organized in 1981 under the laws of the State of Texas.

The Partnership engages in oil and gas development and production in Texas and
is not involved in any industry segment other than oil and gas.

Note 2.     Basis of presentation

In the opinion of management, the unaudited financial statements of the
Partnership as of March 31, 2001 include all adjustments and accruals consisting
only of normal recurring accrual adjustments which are necessary for a fair
presentation of the results for the interim period. These interim results are
not necessarily indicative of results for a full year.

Certain information and footnote disclosure normally included in financial
statements prepared in accordance with generally accepted accounting principles
have been condensed or omitted in these interim financial statements. The
financial statements should be read in conjunction with the financial statements
and the notes thereto contained in the Partnership's report for the year ended
December 31, 2000, a copy of which is available upon request by writing to Rich
Dealy, Vice President and Chief Accounting Officer, 5205 North O'Connor
Boulevard, 1400 Williams Square West, Irving, Texas 75039-3746.

Management's Discussion and Analysis of Financial Condition and
    Results of Operations(1)

Results of Operations

Revenues:

The Partnership's oil and gas revenues increased 15% to $108,191 for the three
months ended March 31, 2001 as compared to $94,181 for the same period in 2000.
The increase in revenues resulted from higher average prices received, offset by
a decline in production. For the three months ended March 31, 2001, 2,157
barrels of oil, 770 barrels of natural gas liquids ("NGLs") and 5,562 mcf of gas
were sold, or 3,854 barrel of oil equivalents ("BOEs"). For the three months
ended March 31, 2000, 2,402 barrels of oil, 1,217 barrels of NGLs and 6,102 mcf
of gas were sold, or 4,636 BOEs.



                                        6
   169



The average price received per barrel of oil increased $1.39, or 5%, from $27.16
for the three months ended March 31, 2000 to $28.55 for the same period in 2001.
The average price received per barrel of NGLs increased $2.13, or 15%, from
$14.58 for the three months ended March 31, 2000 to $16.71 for the same period
in 2001. The average price received per mcf of gas increased 232% from $1.83
during the three months ended March 31, 2000 to $6.07 for the same period in
2001. The market price for oil and gas has been extremely volatile in the past
decade, and management expects a certain amount of volatility to continue in the
foreseeable future. The Partnership may therefore sell its future oil and gas
production at average prices lower or higher than that received during the three
months ended March 31, 2001.

Costs and Expenses:

Total costs and expenses increased to $51,712 for the three months ended March
31, 2001 as compared to $45,205 for the same period in 2000, an increase of
$6,507, or 14%. This increase was primarily due to increases in production
costs, general and administrative expenses ("G&A") and depletion.

Production costs were $44,964 for the three months ended March 31, 2001 and
$40,666 for the same period in 2000 resulting in a $4,298 increase, or 11%. The
increase was due to additional well maintenance costs incurred to stimulate well
production and higher production taxes associated with higher oil and gas
prices.

G&A's components are independent accounting and engineering fees and managing
general partner personnel and administrative costs. During this period, G&A
increased 66% from $2,921 for the three months ended March 31, 2000 to $4,857
for the same period in 2001, primarily due to a higher percentage of the
managing general partner's G&A being allocated (limited to 3% of oil and gas
revenues) as a result of increased oil and gas revenues and an increase in the
accrual for tax preparation fees.

Depletion was $1,891 for the three months ended March 31, 2001 as compared to
$1,618 for the same period in 2000, an increase of $273, or 17%. This increase
was primarily due to a downward revision to one well's proved reserves during
the three months ended March 31, 2001, offset by a decline in oil production of
245 barrels for the period ended March 31, 2001 compared to the same period in
2000.

Liquidity and Capital Resources

Net Cash Provided by Operating Activities

Net cash provided by operating activities increased $24,090 during the three
months ended March 31, 2001 from the same period ended March 31, 2000. This
increase was due to an increase in oil and gas sales receipts of $14,166 and a
reduction in working capital of $16,158, offset by increases in production costs
of $4,298 and G&A expenses of $1,936. The increase in oil and gas receipts
resulted from the increase in commodity prices during 2001 which contributed an



                                        7
   170


additional $444 to oil and gas receipts and $13,722 resulting from an increase
in production during 2001 as compared to the same period in 2000. The increase
in production costs was primarily due to additional well maintenance costs
incurred to stimulate well production and increased production taxes associated
with higher oil and gas prices. The increase in G&A was primarily due to a
higher percentage of the managing general partner's G&A being allocated (limited
to 3% of oil and gas revenues) as a result of increased oil and gas revenues and
an increase in the accrual for tax preparation fees.

Net Cash Used in Investing Activities

For the three months ended March 31, 2001 and 2000, the Partnership's investing
activities included expenditures related to equipment upgrades on active oil and
gas properties.

Net Cash Used in Financing Activities

For the three months ended March 31, 2001, cash distributions to the partners
were $68,431, of which $17,222 was distributed to the general partners and
$51,209 to the limited partners. For the same period ended March 31, 2000, cash
distributions to the partners were $41,860, of which $10,466 was distributed to
the general partners and $31,394 to the limited partners.

Proposal to acquire partnerships

On April 17, 2001, Pioneer Natural Resources Company ("Pioneer") filed a
preliminary proxy statement/prospectus with the Securities and Exchange
Commission proposing an agreement and plan of merger among Pioneer, Pioneer
Natural Resources USA, Inc. ("Pioneer USA"), a wholly-owned subsidiary of
Pioneer, and the limited partners of 46 Parker & Parsley limited partnerships.
Each partnership that approves the agreement and plan of merger and the other
related merger proposals will merge with and into Pioneer USA, and the
partnership interests of each such partnership will be converted into the right
to receive cash and Pioneer common stock. Pioneer USA is the sole or managing
general partner of the partnerships. The Partnership is one of the 46 Parker &
Parsley limited partnerships being requested to approve the agreement and plan
of merger. The preliminary proxy statement/prospectus is non-binding and is
subject to, among other things, consideration of offers from third parties to
purchase any partnership or its assets, the majority approval of the limited
partnership interests in each partnership and the resolution of Securities and
Exchange Commission review comments. No solicitation will be made using
preliminary materials.

----------

(1)   "Management's Discussion and Analysis of Financial Condition and Results
      of Operations" contains forward looking statements that involve risks and
      uncertainties. Accordingly, no assurances can be given that the actual
      events and results will not be materially different than the anticipated
      results described in the forward looking statements.




                                        8


   171
                           PARKER & PARSLEY 81-I, LTD.
                          (A Texas Limited Partnership)


                              FINANCIAL STATEMENTS
                                      WITH
                          INDEPENDENT AUDITORS' REPORT


                           December 31, 2000 and 1999




   172





                          INDEPENDENT AUDITORS' REPORT



The Partners
Parker & Parsley 81-I, Ltd.
  (A Texas Limited Partnership):

We have audited the balance sheets of Parker & Parsley 81-I, Ltd. as of December
31, 2000 and 1999, and the related statements of operations, partners' capital
and cash flows for each of the three years in the period ended December 31,
2000. These financial statements are the responsibility of the Partnership's
management. Our responsibility is to express an opinion on these financial
statements based on our audits.

We conducted our audits in accordance with auditing standards generally accepted
in the United States. Those standards require that we plan and perform the audit
to obtain reasonable assurance about whether the financial statements are free
of material misstatement. An audit includes examining, on a test basis, evidence
supporting the amounts and disclosures in the financial statements. An audit
also includes assessing the accounting principles used and significant estimates
made by management, as well as evaluating the overall financial statement
presentation. We believe that our audits provide a reasonable basis for our
opinion.

In our opinion, the financial statements referred to above present fairly, in
all material respects, the financial position of Parker & Parsley 81-I, Ltd. as
of December 31, 2000 and 1999, and the results of its operations and its cash
flows for each of the three years in the period ended December 31, 2000, in
conformity with accounting principles generally accepted in the United States.



                                      Ernst & Young LLP


Dallas, Texas
March 9, 2001



                                       2
   173


                           PARKER & PARSLEY 81-I, LTD.
                          (A Texas Limited Partnership)

                                 BALANCE SHEETS
                                   December 31





                                                                             2000                 1999
                                                                       ----------------     ----------------
                     ASSETS

                                                                                      
Current assets:
  Cash                                                                 $       38,546       $       38,716
  Accounts receivable - oil and gas sales                                      63,269               34,340
                                                                         ------------         ------------

          Total current assets                                                101,815               73,056
                                                                         ------------         ------------

Oil and gas properties - at cost, based on the
  successful efforts accounting method                                      5,245,144            5,240,632
Accumulated depletion                                                      (5,142,190)          (5,133,431)
                                                                         ------------         ------------

          Net oil and gas properties                                          102,954              107,201
                                                                         ------------         ------------

                                                                       $      204,769       $      180,257
                                                                        =============        =============

LIABILITIES AND PARTNERS' CAPITAL

Current liabilities:
  Accounts payable - affiliate                                         $        8,817       $       10,041

Partners' capital:
  General partners                                                             45,564               38,221
  Limited partners (1,482 interests)                                          150,388              131,995
                                                                         ------------         ------------

                                                                              195,952              170,216
                                                                         ------------         ------------

                                                                       $      204,769       $      180,257
                                                                        =============        =============
















   The accompanying notes are an integral part of these financial statements.



                                       3
   174


                           PARKER & PARSLEY 81-I, LTD.
                          (A Texas Limited Partnership)

                            STATEMENTS OF OPERATIONS
                         For the years ended December 31






                                                        2000        1999        1998
                                                     ---------   ---------   ---------

                                                                    
Revenues:
  Oil and gas                                        $ 416,230   $ 260,652   $ 199,789
  Interest                                               3,071       1,858       2,462
  Gain on disposition of assets                             --          --          67
                                                     ---------   ---------   ---------

                                                       419,301     262,510     202,318
                                                     ---------   ---------   ---------

Costs and expenses:
  Oil and gas production                               174,233     165,810     157,631
  General and administrative                            15,697      13,087       8,892
  Impairment of oil and gas properties                      --          --      50,343
  Depletion                                              8,759      11,881     116,799
                                                     ---------   ---------   ---------

                                                       198,689     190,778     333,665
                                                     ---------   ---------   ---------

Net income (loss)                                    $ 220,612   $  71,732   $(131,347)
                                                     =========   =========   =========

Allocation of net income (loss):
  General partners                                   $  56,242   $  19,205   $  (7,775)
                                                     =========   =========   =========

  Limited partners                                   $ 164,370   $  52,527   $(123,572)
                                                     =========   =========   =========

Net income (loss) per limited partnership interest   $  110.91   $   35.44   $  (83.38)
                                                     =========   =========   =========







   The accompanying notes are an integral part of these financial statements.



                                       4
   175


                           PARKER & PARSLEY 81-I, LTD.
                          (A Texas Limited Partnership)

                         STATEMENTS OF PARTNERS' CAPITAL






                                                                           General              Limited
                                                                           partners             partners               Total
                                                                        --------------       --------------       ---------------
                                                                                                         
Partners' capital at January 1, 1998                                    $       52,826       $      295,972       $     348,798

   Distributions                                                               (10,054)             (45,727)            (55,781)

   Net loss                                                                     (7,775)            (123,572)           (131,347)
                                                                          ------------         ------------         -----------

Partners' capital at December 31, 1998                                          34,997              126,673             161,670

   Distributions                                                               (15,981)             (47,205)            (63,186)

   Net income                                                                   19,205               52,527              71,732
                                                                          ------------         ------------         -----------

Partners' capital at December 31, 1999                                          38,221              131,995             170,216

   Distributions                                                               (48,899)            (145,977)           (194,876)

   Net income                                                                   56,242              164,370             220,612
                                                                          ------------         ------------         -----------

Partners' capital at December 31, 2000                                  $       45,564       $      150,388       $     195,952
                                                                         =============        =============        ============






















   The accompanying notes are an integral part of these financial statements.



                                       5
   176


                          PARKER & PARSLEY 81-I, LTD.
                         (A Texas Limited Partnership)

                            STATEMENTS OF CASH FLOWS
                        For the years ended December 31





                                                                             2000                 1999                 1998
                                                                        --------------       --------------       --------------

                                                                                                        
Cash flows from operating activities:
   Net income (loss)                                                    $     220,612        $      71,732       $     (131,347)
   Adjustments to reconcile net income (loss) to
      net cash provided by operating activities:
         Impairment of oil and gas properties                                     -                    -                 50,343
         Depletion                                                              8,759               11,881              116,799
         Gain on disposition of assets                                            -                    -                    (67)
   Changes in assets and liabilities:
         Accounts receivable                                                  (28,929)             (11,525)              12,794
         Accounts payable                                                      (1,224)               2,906               (3,523)
                                                                          -----------           ----------         ------------

             Net cash provided by operating activities                        199,218               74,994               44,999
                                                                          -----------          -----------         ------------

Cash flows from investing activities:
   Additions to oil and gas properties                                         (4,512)              (3,421)              (2,481)
   Proceeds from asset dispositions                                               -                    -                 14,234
                                                                          -----------          -----------         ------------

             Net cash provided by (used in) investing activities               (4,512)              (3,421)              11,753
                                                                          -----------          -----------         ------------

Cash flows used in financing activities:
   Cash distributions to partners                                            (194,876)             (63,186)             (55,781)
                                                                          -----------          -----------         ------------

Net increase (decrease) in cash                                                  (170)               8,387                  971
Cash at beginning of year                                                      38,716               30,329               29,358
                                                                          -----------          -----------         ------------

Cash at end of year                                                     $      38,546        $      38,716       $       30,329
                                                                         ============         ============        =============




   The accompanying notes are an integral part of these financial statements.



                                       6
   177


                           PARKER & PARSLEY 81-I, LTD.
                          (A Texas Limited Partnership)

                          NOTES TO FINANCIAL STATEMENTS
                        December 31, 2000, 1999 and 1998


NOTE 1. ORGANIZATION AND NATURE OF OPERATIONS

        Parker & Parsley 81-I, Ltd. (the "Partnership") is a limited partnership
organized in 1981 under the laws of the State of Texas. The Partnership's
general partners are Pioneer Natural Resources USA, Inc. ("Pioneer USA") and P&P
Employees 81-I, Ltd. ("EMPL"). The Partnership's managing general partner is
Pioneer USA.

        The Partnership engages in oil and gas development and production in
Texas and is not involved in any industry segment other than oil and gas.

NOTE 2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

        A summary of the significant accounting policies consistently applied in
the preparation of the accompanying financial statements follows:

        Oil and gas properties - The Partnership utilizes the successful efforts
method of accounting for its oil and gas properties and equipment. Under this
method, all costs associated with productive wells and nonproductive development
wells are capitalized while nonproductive exploration costs are expensed.
Capitalized costs relating to proved properties are depleted using the
unit-of-production method on a property-by-property basis based on proved oil
(dominant mineral) reserves as evaluated by independent petroleum consultants.
The carrying amounts of properties sold or otherwise disposed of and the related
allowances for depletion are eliminated from the accounts and any gain or loss
is included in results of operations.

        Impairment of long-lived assets - In accordance with Statement of
Financial Accounting Standards No. 121, "Accounting for the Impairment of
Long-Lived Assets and for Long-Lived Assets to be Disposed Of" ("SFAS 121"), the
Partnership reviews its long-lived assets to be held and used on an individual
property basis, including oil and gas properties accounted for under the
successful efforts method of accounting, whenever events or circumstances
indicate that the carrying value of those assets may not be recoverable. An
impairment loss is indicated if the sum of the expected future cash flows is
less than the carrying amount of the assets. In this circumstance, the
Partnership recognizes an impairment loss for the amount by which the carrying
amount of the asset exceeds the estimated fair value of the asset.

        Use of estimates in the preparation of financial statements -
Preparation of the accompanying financial statements in conformity with
generally accepted accounting principles requires management to make estimates
and assumptions that affect the reported amounts of assets and liabilities and
disclosure of contingent assets and liabilities at the date of the financial
statements and the reported amounts of revenues and expenses during the
reporting periods. Actual results could differ from those estimates.



                                       7
   178

        Net income (loss) per limited partnership interest - The net income
(loss) per limited partnership interest is calculated by using the number of
outstanding limited partnership interests.

        Income taxes - A Federal income tax provision has not been included in
the financial statements as the income of the Partnership is included in the
individual Federal income tax returns of the respective partners.

        Statements of cash flows - For purposes of reporting cash flows, cash
includes depository accounts held by banks.

        General and administrative expenses - General and administrative
expenses are allocated in part to the Partnership by the managing general
partner. Allocated expenses are determined by the managing general partner based
upon the level of activity of the Partnership relative to the non-partnership
activities of the managing general partner. The method of allocation has been
consistent over the past several years with certain modifications incorporated
to reflect changes in Pioneer USA's overall business activities.

        Reclassifications - Certain reclassifications may have been made to the
1999 and 1998 financial statements to conform to the 2000 financial statement
presentations.

        Environmental - The Partnership is subject to extensive federal, state
and local environmental laws and regulations. These laws, which are constantly
changing, regulate the discharge of materials into the environment and may
require the Partnership to remove or mitigate the environmental effects of the
disposal or release of petroleum or chemical substances at various sites.
Environmental expenditures are expensed or capitalized depending on their future
economic benefit. Expenditures that relate to an existing condition caused by
past operations and that have no future economic benefits are expensed.
Liabilities for expenditures of a noncapital nature are recorded when
environmental assessment and/or remediation is probable, and the costs can be
reasonably estimated. Such liabilities are generally undiscounted unless the
timing of cash payments for the liability or component are fixed or reliably
determinable. No such liabilities have been accrued as of December 31, 2000.

        Revenue recognition - The Partnership uses the entitlements method of
accounting for oil, natural gas liquids ("NGLs") and natural gas revenues.

NOTE 3. IMPAIRMENT OF LONG-LIVED ASSETS

        In accordance with SFAS 121, the Partnership reviews its proved oil and
gas properties for impairment whenever events and circumstances indicate a
decline in the recoverability of the carrying value of the Partnership's oil and
gas properties. The Partnership has estimated the expected future cash flows of
its oil and gas properties as of December 31, 2000, 1999 and 1998, based on
proved reserves, and compared such estimated future cash flows to the respective
carrying amount of the oil and gas properties to determine if the carrying
amounts were likely to be recoverable. For those proved oil and gas properties
for which the carrying amount exceeded the estimated future cash flows, an
impairment was determined to exist; therefore, the Partnership adjusted the
carrying amount of those oil and gas properties to their fair value as
determined by discounting their expected future cash flows at a discount rate
commensurate with the risks involved



                                       8
   179

in the industry. As a result, the Partnership recognized a non-cash impairment
provision of $50,343 related to its proved oil and gas properties during 1998.

NOTE 4. INCOME TAXES

        The financial statement basis of the Partnership's net assets and
liabilities was $308,345 less than the tax basis at December 31, 2000.

        The following is a reconciliation of net income (loss) per statements of
operations with the net income per Federal income tax returns for the years
ended December 31:



                                                                              2000                1999                1998
                                                                         --------------      --------------      --------------

                                                                                                        
        Net income (loss) per statements of operations                   $     220,612       $      71,732       $    (131,347)
        Depletion and depreciation provisions for tax
           reporting purposes less than amounts for
           financial reporting purposes                                          6,157               9,884             114,643
        Impairment of oil and gas properties for
           financial reporting purposes                                            -                   -                50,343
        Other, net                                                                (447)                (62)                 81
                                                                           -----------        ------------         -----------

                Net income per Federal income tax returns                $     226,322       $      81,554       $      33,720
                                                                          ============        ============        ============


NOTE 5. OIL AND GAS PRODUCING ACTIVITIES

        The following is a summary of the costs incurred, whether capitalized or
expensed, related to the Partnership's oil and gas producing activities for the
years ended December 31:



                                                                             2000                 1999                 1998
                                                                        --------------       --------------       --------------

                                                                                                        
        Property acquisition costs                                      $        4,512       $       3,421       $        2,481
                                                                         =============        ============        =============


        Capitalized oil and gas properties consist of the following:



                                                                                                   2000                1999
                                                                                             ----------------    ----------------
                                                                                                           
        Proved properties:
           Property acquisition costs                                                       $       156,084      $       156,084
           Completed wells and equipment                                                          5,089,060            5,084,548
                                                                                              -------------        -------------

                                                                                                  5,245,144            5,240,632
        Accumulated depletion                                                                    (5,142,190)          (5,133,431)
                                                                                              -------------        -------------

                Net oil and gas properties                                                  $       102,954      $       107,201
                                                                                             ==============       ==============



NOTE 6. RELATED PARTY TRANSACTIONS

        Pursuant to the limited partnership agreement, the Partnership had the
following related party transactions with the managing general partner during
the years ended December 31:



                                       9
   180



                                                                              2000                1999                 1998
                                                                         --------------      --------------       --------------

                                                                                                         
        Payment of lease operating and supervision
           charges in accordance with standard industry
           operating agreements                                          $      78,719       $      73,881        $     76,809

        Reimbursement of general and administrative
           expenses                                                      $      12,487       $       7,820        $      6,250


        Pioneer USA, EMPL and the Partnership are parties to the Partnership
agreement. EMPL is a limited partnership in which Pioneer USA owns 60% and the
remaining portion is owned by former affiliates.

        The costs and revenues of the Partnership are allocated as follows:



                                                                                        General                   Limited
                                                                                        partners                  partners
                                                                                        --------                  --------
                                                                                                               
     Revenues:
        Proceeds from property dispositions prior to cost
          recovery                                                                         10%                       90%
        All other Partnership revenues                                                     25%                       75%
     Costs and expenses:
        Lease acquisition costs, drilling and completion
          costs and all other costs                                                        10%                       90%
        Operating costs, direct costs and general and
          administrative expenses                                                          25%                       75%


NOTE 7. OIL AND GAS INFORMATION (UNAUDITED)

        The following table presents information relating to the Partnership's
estimated proved oil and gas reserves at December 31, 2000, 1999 and 1998 and
changes in such quantities during the years then ended. All of the Partnership's
reserves are proved developed and located within the United States. The
Partnership's reserves are based on an evaluation prepared by Williamson
Petroleum Consultants, Inc., an independent petroleum consultant, using criteria
established by the Securities and Exchange Commission.




                                       10
   181




                                                Oil and NGLs            Gas
                                                  (bbls)               (mcf)
                                                 --------            --------

                                                              
Net proved reserves at January 1, 1998            131,090             275,544
Revisions                                         (70,930)           (119,307)
Production                                        (13,937)            (24,638)
                                                 --------            --------

Net proved reserves at December 31, 1998           46,223             131,599
Revisions                                         160,567             219,656
Production                                        (14,970)            (28,708)
                                                 --------            --------

Net proved reserves at December 31, 1999          191,820             322,547
Revisions                                          33,336             130,129
Production                                        (13,976)            (25,901)
                                                 --------            --------

Net proved reserves at December 31, 2000          211,180             426,775
                                                 ========            ========


        As of December 31, 2000, the estimated present value of future net
revenues of proved reserves, calculated using December 31, 2000 prices of $26.64
per barrel of oil, $13.30 per barrel of NGLs and $7.65 per mcf of gas,
discounted at 10% was approximately $1,915,000 and undiscounted was $3,748,000.

        Numerous uncertainties exist in estimating quantities of proved reserves
and future net revenues therefrom. The estimates of proved reserves and related
future net revenues set forth in this Report are based on various assumptions,
which may ultimately prove to be inaccurate. Therefore, such estimates should
not be construed as estimates of the current market value of the Partnership's
proved reserves. The Partnership emphasizes that reserve estimates are
inherently imprecise and, accordingly, the estimates are expected to change as
future information becomes available.

Disclosures about Oil & Gas Producing Activities

Standardized Measure of Discounted Future Net Cash Flows

       The standardized measure of discounted future net cash flows is computed
by applying year-end prices of oil and gas (with consideration of price changes
only to the extent provided by contractual arrangements) to the estimated future
production of proved oil and gas reserves less estimated future expenditures
(based on year-end costs) to be incurred in developing and producing the proved
reserves, discounted using a rate of 10% per year to reflect the estimated
timing of the future cash flows. A Federal income tax provision has not been
calculated as the income of the Partnership is included in the individual
Federal income tax returns of the respective partners.

       Discounted future cash flow estimates like those shown below are not
intended to represent estimates of the fair value of oil and gas properties.
Estimates of fair value should also consider anticipated future oil and gas
prices, interest rates, changes in development and production costs and risks
associated with future production. Because of these and other considerations,
any estimate of fair value is necessarily subjective and imprecise.






                                       11
   182




                                                                                  For the years ended December 31,
                                                                        ---------------------------------------------------
                                                                              2000                1999               1998
                                                                        ----------------    ----------------   ----------------
                                                                                             (in thousands)
                                                                                                      
Oil and gas producing activities:
   Future cash inflows                                                  $         7,853     $        4,776     $           583
   Future production costs                                                       (4,105)            (3,078)               (433)
                                                                          -------------       ------------       -------------

                                                                                  3,748              1,698                 150
   10% annual discount factor                                                    (1,833)              (734)                (64)
                                                                          -------------       ------------       -------------

   Standardized measure of discounted future net cash flows             $         1,915     $          964     $            86
                                                                         ==============      =============      ==============





                                                                                  For the years ended December 31,
                                                                        ---------------------------------------------------
                                                                              2000                1999               1998
                                                                        ----------------    ----------------   ----------------
                                                                                             (in thousands)
                                                                                                      
   Oil and Gas Producing Activities:
      Oil and gas sales, net of production costs                        $          (242)    $          (95)    $          (42)
      Net changes in prices and production costs                                    888                180               (301)
      Revisions of previous quantity estimates                                      415                788               (112)
      Accretion of discount                                                          96                  8                 52
      Changes in production rates, timing and other                                (206)                (3)               (33)
                                                                          -------------       ------------       ------------

      Change in present value of future net revenues                                951                878               (436)
                                                                          -------------       ------------       ------------

      Balance, beginning of year                                                    964                 86                522
                                                                          -------------       ------------       ------------

      Balance, end of year                                              $         1,915     $          964     $           86
                                                                         ==============      =============      =============


NOTE 8. MAJOR CUSTOMERS

        The following table reflects the major customers of the Partnership's
oil and gas sales (a major customer is defined as a customer whose sales exceed
10% of total sales) during the years ended December 31:


                                                                                2000                1999               1998
                                                                              --------            --------           --------

                                                                                                            
                    Plains Marketing, L.P.                                       54%                 51%                 -
                    Genesis Crude Oil, L.P.                                       -                   -                 59%
                    Western Gas Resources, Inc.                                   -                   6%                18%
                    Exxon Corporation                                             8%                  7%                11%


        At December 31, 2000, the amount receivable from Plains Marketing, L.P.
was $19,892 which is included in the caption "Accounts receivable - oil and gas
sales" in the accompanying Balance Sheet.

        Pioneer USA is of the opinion that the loss of any one purchaser would
not have an adverse effect on the ability of the Partnership to sell its oil,
NGLs and gas production.







                                       12
   183


NOTE 9. PARTNERSHIP AGREEMENT

        The following is a brief summary of the more significant provisions of
the limited partnership agreement:

        General partners - The general partners of the Partnership are Pioneer
        USA and EMPL. Pioneer USA, the managing general partner, has the power
        and authority to manage, control and administer all Partnership affairs.
        As managing general partner and operator of the Partnership's
        properties, all production expenses are incurred by Pioneer USA and
        billed to the Partnership. The majority of the Partnership's oil and gas
        revenues are received directly by the Partnership, however, a portion of
        the oil and gas revenue is initially received by Pioneer USA prior to
        being paid to the Partnership.

        Limited partner liability - The maximum amount of liability of any
        limited partner is the total contributions of such partner plus his
        share of any undistributed profits.

        Initial capital contributions - The limited partners entered into
        subscription agreements for aggregate capital contributions of
        $7,410,000. The general partners are required to contribute amounts
        equal to 10% of Partnership expenditures for lease acquisition, drilling
        and completion and 25% of direct, general and administrative and
        operating expenses.



                                       13




   184
                           PARKER & PARSLEY 81-I, LTD.
                          (A TEXAS LIMITED PARTNERSHIP)

THIS REPORT CONTAINS FORWARD LOOKING STATEMENTS THAT INVOLVE RISKS AND
UNCERTAINTIES. ACCORDINGLY, NO ASSURANCES CAN BE GIVEN THAT THE ACTUAL EVENTS
AND RESULTS WILL NOT BE MATERIALLY DIFFERENT THAN THE ANTICIPATED RESULTS
DESCRIBED IN THE FORWARD LOOKING STATEMENTS.

MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND
     RESULTS OF OPERATIONS

Results of operations

2000 compared to 1999

The Partnership's oil and gas revenues increased 60% to $416,230 for 2000 as
compared to $260,652 in 1999. The increase in revenues resulted from higher
average prices received, offset by a decrease in production. In 2000, 8,793
barrels of oil, 5,183 barrels of natural gas liquids ("NGLs") and 25,901 mcf of
gas were sold, or 18,293 barrel of oil equivalents ("BOEs"). In 1999, 9,249
barrels of oil, 5,721 barrels of NGLs and 28,708 mcf of gas were sold, or 19,755
BOEs. Due to the decline characteristics of the Partnership's oil and gas
properties, management expects a certain amount of decline in production in the
future until the Partnership's economically recoverable reserves are fully
depleted.

The average price received per barrel of oil increased $12.32, or 73%, from
$16.94 in 1999 to $29.26 in 2000. The average price received per barrel of NGLs
increased $5.38, or 58%, from $9.22 in 1999 to $14.60 in 2000. The average price
received per mcf of increased 81% from $1.78 in 1999 to $3.22 in 2000. The
market price for oil and gas has been extremely volatile in the past decade, and
management expects a certain amount of volatility to continue in the foreseeable
future. The Partnership may therefore sell its future oil and gas production at
average prices lower or higher than that received in 2000.

Total costs and expenses increased in 2000 to $198,689 as compared to $190,778
in 1999, an increase of $7,911, or 4%. The increase was primarily due to an
increase in production costs and general and administrative expenses ("G&A"),
offset by a decline in depletion.

Production costs were $174,233 in 2000 and $165,810 in 1999, resulting in an
$8,423 increase, or 5%. The increase was primarily due to higher production
taxes associated with higher oil and gas prices, offset by less well maintenance
costs.

G&A's components are independent accounting and engineering fees and managing
general partner personnel and operating costs. During this period, G&A increased
20% from $13,087 in 1999 to $15,697 in 2000, primarily due to a higher
percentage of the managing general partner's G&A being allocated (limited to 3%
of oil and gas revenues) as a result of increased oil and gas revenues. The
Partnership paid the managing general partner $12,487 in 2000 and $7,820 in 1999
for G&A incurred on behalf of the Partnership. The remaining G&A was paid
directly by the Partnership. The managing general partner determines the
allocated expenses based upon the level of activity of the Partnership relative
to the non-partnership activities of the managing general partner. The method of
allocation has been consistent over the past several years with certain
modifications incorporated to reflect changes in Pioneer USA's overall business
activities.

Depletion was $8,759 in 2000 as compared to $11,881 in 1999, representing a
decrease of $3,122, or 26%. This decrease was primarily due to a 20,821 barrels
of oil increase in proved reserves during 2000 as a result of the higher
commodity prices.

1999 compared to 1998

The Partnership's 1999 oil and gas revenues increased 30% to $260,652 from
$199,789 in 1998. The increase in revenues resulted from higher average prices
received and an increase in production. In 1999, 9,249 barrels of oil, 5,721
barrels of NGLs and 28,708 mcf of gas were sold, or 19,755 BOEs. In 1998, 9,634
barrels of oil, 4,303 barrels of NGLs and 24,638 mcf of gas were sold, or 18,043
BOEs.



   185

The average price received per barrel of oil increased $3.61, or 27%, from
$13.33 in 1998 to $16.94 in 1999. The average price received per barrel of NGLs
increased $2.82, or 44%, from $6.40 in 1998 to $9.22 in 1999. The average price
received per mcf of gas remained unchanged at $1.78 in 1998 and 1999.

Total costs and expenses decreased in 1999 to $190,778 as compared to $333,665
in 1998, a decrease of $142,887, or 43%. The decrease was primarily due to
declines in depletion and the impairment of oil and gas properties, offset by an
increase in production costs and G&A.

Production costs were $165,810 in 1999 and $157,631 in 1998, resulting in an
$8,179 increase, or 5%. The increase was due to additional well maintenance
costs incurred to stimulate well production and an increase in production taxes
due to increased oil and gas revenues, offset by a decline in ad valorem taxes.

During this period, G&A increased 47% from $8,892 in 1998 to $13,087 in 1999
primarily due to a higher percentage of the managing general partner's G&A being
allocated (limited to 3% of oil and gas revenues) as a result of increased oil
and gas revenues. The Partnership paid the managing general partner $7,820 in
1999 and $6,250 in 1998 for G&A incurred on behalf of the Partnership.

In accordance with Statement of Financial Accounting Standards No. 121,
"Accounting for the Impairment of Long-Lived Assets and for Long-Lived Assets to
be Disposed Of" ("SFAS 121"), the managing general partner reviews the
Partnership's oil and gas properties for impairment whenever events or
circumstances indicate a decline in the recoverability of the carrying value of
the Partnership's assets may have occurred. As a result of the review and
evaluation of its long-lived assets for impairment, the Partnership recognized a
non-cash charge of $50,343 related to its oil and gas properties during 1998.

Depletion was $11,881 in 1999 compared to $116,799 in 1998, representing a
decrease of $104,918, or 90%. This decrease was the result of a combination of
factors that included an increase in proved reserves of 104,672 barrels of oil
during 1999 as a result of the higher commodity prices, a reduction in the
Partnership's net depletable basis from charges taken in accordance with SFAS
121 during the fourth quarter of 1998 and a decline in oil production of 385
barrels for the period ended December 31, 1999 compared to the same period in
1998.

Petroleum industry

The petroleum industry has been characterized by volatile oil, NGL and natural
gas commodity prices and relatively stable supplier costs during the three years
ended December 31, 2000. During 1998, weather patterns, regional economic
recessions and political matters combined to cause worldwide oil supplies to
exceed demand resulting in a substantial decline in oil prices. Also during
1998, but to a lesser extent, market prices for natural gas declined. During
1999 and 2000, the Organization of Petroleum Exporting Countries ("OPEC") and
certain other crude oil exporting nations announced reductions in their planned
export volumes. Those announcements, together with the enactment of the
announced reductions in export volumes, had a positive impact on world oil
prices, as have overall natural gas supply and demand fundamentals on North
American natural gas prices. Although the favorable commodity price environment
and stable field service cost environment is expected to continue during 2001,
there is no assurance that commodity prices will not return to a less favorable
level or that field service costs will not escalate in the future, both of which
could negatively impact the Partnership's future results of operations and cash
distributions.

Liquidity and capital resources

Net Cash Provided by Operating Activities

Net cash provided by operating activities increased $124,224 during the year
ended December 31, 2000 from 1999. This increase was due to an increase in oil
and gas sales receipts of $156,791, offset by increases in production costs paid
of $8,423, G&A expenses paid of $2,610 and working capital of $21,534. The
increase in oil and gas receipts resulted from the increase in commodity prices
during 2000 which contributed an additional $187,015 to oil and gas receipts,
offset by $30,224 resulting from the decline in production during 2000. The
increase in production costs was primarily due to increased production taxes
associated with higher oil and gas prices, offset by lower well maintenance
costs. The increase in G&A was primarily due to higher percentage of the
managing general partner's G&A being allocated (limited to 3% of oil and gas
revenues) as a result of increased oil and gas revenues.



   186

Net Cash Provided by (Used in) Investing Activities

The Partnership's principal investing activities during 2000 and 1999 included
expenditures related to upgrades of equipment on various oil and gas properties.

Net Cash Used in Financing Activities

In 2000, cash distributions to the partners were $194,876, of which $48,899 was
distributed to the general partners and $145,977 to the limited partners. In
1999, cash distributions to the partners were $63,186, of which $15,981 was
distributed to the general partners and $47,205 to the limited partners.








   187



                           PARKER & PARSLEY 81-I, LTD.

SELECTED FINANCIAL DATA

The following selected financial data for the Partnership should be read in
connection with Management's Discussion and Analysis of Financial Condition and
Results of Operations and the financial statements included in the attached
supplemental information.



                                        Three months
                                            ended
                                          March 31,                       Years ended December 31,
                                   ---------------------   --------------------------------------------------------------
                                     2001        2000         2000         1999         1998         1997         1996
                                   --------   ----------   ----------   ----------   ----------   ----------   ----------
                                                                                          
Operating results:
  Oil and gas sales                $          $   94,181   $  416,230   $  260,652   $  199,789   $  279,957   $  396,128
                                   ========   ==========   ==========   ==========   ==========   ==========   ==========

  Impairment of oil and
    gas properties                 $          $       --   $       --   $       --   $   50,343   $  255,709   $       --
                                   ========   ==========   ==========   ==========   ==========   ==========   ==========

  Gain on litigation
      settlement, net              $          $       --   $       --   $       --   $       --   $       --   $   30,621
                                   ========   ==========   ==========   ==========   ==========   ==========   ==========

  Net income (loss)                $          $   49,539   $  220,612   $   71,732   $ (131,347)  $ (241,864)  $  203,620
                                   ========   ==========   ==========   ==========   ==========   ==========   ==========

  Allocation of net
    income (loss):
         Managing general
           partner                 $          $   12,628   $   56,242   $   19,205   $   (7,775)  $  (11,941)  $   54,950
                                   ========   ==========   ==========   ==========   ==========   ==========   ==========

         Limited partners          $          $   36,911   $  164,370   $   52,527   $ (123,572)  $ (229,923)  $  148,670
                                   ========   ==========   ==========   ==========   ==========   ==========   ==========

  Limited partners' net
    income (loss) per limited
    partnership interest           $          $    24.91   $   110.91   $    35.44   $   (83.38)  $  (155.14)  $   100.32
                                   ========   ==========   ==========   ==========   ==========   ==========   ==========

  Limited partners' cash
    distributions per limited
    partnership interest           $          $    21.18   $    98.50   $    31.85   $    30.85   $    68.90   $   107.95(a)
                                   ========   ==========   ==========   ==========   ==========   ==========   ==========

At year end:
  Total assets                     $          $  187,763   $  204,769   $  180,257   $  168,805   $  359,456   $  734,832
                                   ========   ==========   ==========   ==========   ==========   ==========   ==========


----------

(a)  Including litigation settlement per limited partnership interest of $20.66
     in 1996.



   188
                        PIONEER NATURAL RESOURCES COMPANY
                       PIONEER NATURAL RESOURCES USA, INC.
                            1400 WILLIAMS SQUARE WEST
                            5205 NORTH O'CONNOR BLVD.
                               IRVING, TEXAS 75039

                            SUPPLEMENTAL INFORMATION

                                       OF

            PARKER & PARSLEY 81-II LTD., A TEXAS LIMITED PARTNERSHIP

                                       TO

                 PROXY STATEMENT/PROSPECTUS DATED        , 2001

                                   ----------

                  THE DATE OF THIS SUPPLEMENT IS        , 2001

                                   ----------


     This document contains important information specific to Parker & Parsley
81-II Ltd. and supplements the proxy statement/prospectus dated          , 2001,
of Pioneer Natural Resources Company and Pioneer Natural Resources USA, Inc.,
by which Pioneer USA is soliciting proxies to be voted at a special meeting of
limited partners of the partnership. The purpose of the special meeting is for
you to vote upon the merger of the partnership with and into Pioneer USA that,
if completed, will result in your receiving common stock of Pioneer Natural
Resources Company for your partnership interests.


     This document contains the following information concerning Parker &
Parsley 81-II Ltd.:

     o    A table containing:

          --   the aggregate initial investment by the limited partners


          --   the aggregate historical limited partner distributions through
               July 31, 2001

          --   the merger value attributable to partnership interests of limited
               partners, excluding Pioneer USA

          --   the merger value per $1,000 limited partner investment

          --   the merger value per $1,000 limited partner investment as a
               multiple of distributions for the past four quarterly
               distributions including the distribution in July 2001


          --   the book value per $1,000 limited partner investment as of March
               31, 2001 and as of December 31, 2000


          --   the going concern value per $1,000 limited partner investment

          --   the liquidation value per $1,000 limited partner investment


          --   the ordinary tax loss per $1,000 limited partner investment in
               year of initial investment

     o    Information about:


          --   the legal opinion for the limited partners

          --   the term of the partnership


     o    The partnership's financial statements, including management's
          discussion and analysis of financial condition and results of
          operations, for the three months ended March 31, 2001

     o    The partnership's financial statements, including management's
          discussion and analysis of financial condition and results of
          operations, for the year ended December 31, 2000

     o    Selected historical financial data for the partnership for the three
          months ended March 31, 2001 and 2000 and the five years ended December
          31, 2000



                                       -1-
   189

                           PARKER & PARSLEY 81-II LTD.

                         SUPPLEMENTAL INFORMATION TABLE



                                                                                         
Aggregate Initial Investment by the Limited Partners(a)                                     $   6,440

Aggregate Historical Limited Partner Distributions through July 31, 2001(a)                 $   5,422

Merger Value Attributable to Partnership Interests of Limited Partners, Excluding Pioneer   $     470
USA(a), (b)

Merger Value per $1,000 Limited Partner Investment(b), (c)                                  $   73.34

Merger Value per $1,000 Limited Partner Investment as a Multiple of Distributions for the        3.02 times
past four quarterly distributions including the distribution in July 2001(b), (c)

Book Value per $1,000 Limited Partner Investment:

        -- as of March 31, 2001(c)                                                          $   82.82

        -- as of December 31, 2000(c)                                                       $   84.93

Going Concern Value per $1,000 Limited Partner Investment(c), (d)                           $   66.14

Liquidation Value per $1,000 Limited Partner Investment(c), (e)                             $   71.21

Ordinary Tax Loss per $1,000 Limited Partner Investment in Year of Initial Investment       $     290
(c), (f)




----------

(a)  Stated in thousands.


(b)  The merger value for the partnership is equal to the sum of the present
     value of estimated future net revenues from the partnership's estimated oil
     and gas reserves and its net working capital, in each case as of March 31,
     2001, less its pro rata share, based on its reserve value, of the estimated
     expenses and fees of the mergers of all of the partnerships and less the
     cash distribution on or about July 9, 2001, by the partnership to its
     partners.

(c)  Interests in some partnerships were sold in units at prices other than
     $1,000. We have presented this information based on a $1,000 initial
     investment for ease of use and comparison among partnerships. You should
     not assume that the amount shown per $1,000 investment is the same as the
     value or amount attributable to a single unit investment.

(d)  The going concern value for the partnership is based upon: (1) the sum of
     (A) the estimated net cash flow from the sale of the partnership's reserves
     during a 10-year operating period and (B) the estimated residual value from
     the sale of the partnership's remaining reserves at the end of the
     operating period, in each case using the same pricing and discount rate as
     in the merger value calculation, less (2) partnership level general and
     administrative expenses.

(e)  The liquidation value for the partnership is based upon the sale of the
     partnership's reserves at the reserve value, less liquidation expenses
     which are estimated to be the sum of (1) the partnership's pro rata share
     of the merger expenses and fees described in footnote (b) above and (2) 3%
     of the partnership's reserve value. The liquidation expenses represent the
     estimated costs to retain an investment banker or broker to sell the assets
     of the partnership and the legal and other closing costs associated with
     such transaction, including the wind-down costs of the partnership.

(f)  Your ability to use your distributive share of the partnership's loss to
     offset your other income may have been subject to certain limitations at
     your level as a partner, and you may therefore wish to consult your tax
     advisor to determine the additional value, if any, actually realized by you
     in your particular circumstances.


          INFORMATION ABOUT THE LEGAL OPINION FOR THE LIMITED PARTNERS

     The partnership agreement for the partnership requires that special legal
counsel render an opinion on behalf of the limited partners to Pioneer USA that
(1) neither the grant nor the exercise of the right to approve the merger of the
partnership by its limited partners will adversely affect the federal income tax
status or classification of the partnership or any of its limited partners; and
(2) neither the grant nor exercise of such right will result in the loss of any
limited partner's limited liability. In addition, the counsel designated to
render the opinion must be counsel other than counsel to Pioneer USA or the
partnership. Both the designated counsel and the legal opinion must be approved
by the limited partners. Pioneer USA has retained __________ of Dallas, Texas
for the purpose of rendering this legal opinion on behalf of the limited
partners to Pioneer USA. The merger proposals include an approval of that
counsel and the form of its opinion. A copy of the opinion is attached as an
exhibit to the merger proposals.


                  INFORMATION ABOUT THE TERM OF THE PARTNERSHIP

     The term of the partnership shall continue until terminated in accordance
with the applicable provisions of its partnership agreement.




                                       -2-
   190

                          PARKER & PARSLEY 81-II, LTD.

                          (A Texas Limited Partnership)


                              FINANCIAL STATEMENTS

                                 March 31, 2001



   191



                          PARKER & PARSLEY 81-II, LTD.
                          (A Texas Limited Partnership)

                                 BALANCE SHEETS




                                                      March 31,      December 31,
                                                         2001            2000
                                                     ------------    ------------
                                                     (Unaudited)
                                                               
                 ASSETS
Current assets:
  Cash                                               $     32,452    $     29,376
  Accounts receivable - oil and gas sales                  53,674          64,821
                                                     ------------    ------------
        Total current assets                               86,126          94,197
                                                     ------------    ------------
Oil and gas properties - at cost, based on the
  successful efforts accounting method                  5,347,556       5,345,296
Accumulated depletion                                  (4,832,578)     (4,821,914)
                                                     ------------    ------------
        Net oil and gas properties                        514,978         523,382
                                                     ------------    ------------
                                                     $    601,104    $    617,579
                                                     ============    ============

LIABILITIES AND PARTNERS' CAPITAL

Current liabilities:
  Accounts payable - affiliate                       $      9,487    $      9,253

Partners' capital:
  General partners                                         58,234          61,405
  Limited partners (1,153 interests)                      533,383         546,921
                                                     ------------    ------------
                                                          591,617         608,326
                                                     ------------    ------------
                                                     $    601,104    $    617,579
                                                     ============    ============



The financial information included as of March 31, 2001 has been prepared by the
managing general partner without audit by independent public accountants.

   The accompanying notes are an integral part of these financial statements.



                                        2
   192

                          PARKER & PARSLEY 81-II, LTD.
                          (A Texas Limited Partnership)

                            STATEMENTS OF OPERATIONS
                                   (Unaudited)




                                                Three months ended
                                                     March 31,
                                              -----------------------
                                                 2001         2000
                                              ----------   ----------
                                                     
Revenues:
  Oil and gas                                 $  108,066   $   70,001
  Interest                                           682          397
                                              ----------   ----------
                                                 108,748       70,398
                                              ----------   ----------
Costs and expenses:
  Oil and gas production                          50,840       48,539
  General and administrative                       4,448        2,190
  Depletion                                       10,664       11,747
                                              ----------   ----------
                                                  65,952       62,476
                                              ----------   ----------
Net income                                    $   42,796   $    7,922
                                              ==========   ==========
Allocation of net income:
  General partners                            $   12,044   $    3,743
                                              ==========   ==========
  Limited partners                            $   30,752   $    4,179
                                              ==========   ==========
Net income per limited partnership interest   $    26.67   $     3.62
                                              ==========   ==========




         The financial information included herein has been prepared by the
managing general partner without audit by independent public accountants.

   The accompanying notes are an integral part of these financial statements.



                                        3
   193

                          PARKER & PARSLEY 81-II, LTD.
                          (A Texas Limited Partnership)

                         STATEMENT OF PARTNERS' CAPITAL
                                   (Unaudited)





                              General       Limited
                              partners      partners       Total
                             ----------    ----------    ----------
                                                
Balance at January 1, 2001   $   61,405    $  546,921    $  608,326

    Distributions               (15,215)      (44,290)      (59,505)

    Net income                   12,044        30,752        42,796
                             ----------    ----------    ----------

Balance at March 31, 2001    $   58,234    $  533,383    $  591,617
                             ==========    ==========    ==========



         The financial information included herein has been prepared by the
managing general partner without audit by independent public accountants.

   The accompanying notes are an integral part of these financial statements.



                                        4
   194

                          PARKER & PARSLEY 81-II, LTD.
                          (A Texas Limited Partnership)

                            STATEMENTS OF CASH FLOWS
                                   (Unaudited)




                                                       Three months ended
                                                            March 31,
                                                     ------------------------
                                                        2001          2000
                                                     ----------    ----------
                                                             
Cash flows from operating activities:
  Net income                                         $   42,796    $    7,922
  Adjustments to reconcile net income to net
    cash provided by operating activities:
       Depletion                                         10,664        11,747
  Changes in assets and liabilities:
       Accounts receivable                               11,147        (9,005)
       Accounts payable                                     234          (108)
                                                     ----------    ----------
         Net cash provided by operating activities       64,841        10,556
                                                     ----------    ----------
Cash flows used in investing activities:
  Additions to oil and gas properties                    (2,260)       (1,329)

Cash flows used in financing activities:
  Cash distributions to partners                        (59,505)      (16,316)
                                                     ----------    ----------
Net increase (decrease) in cash                           3,076        (7,089)
Cash at beginning of period                              29,376        30,160
                                                     ----------    ----------
Cash at end of period                                $   32,452    $   23,071
                                                     ==========    ==========




         The financial information included herein has been prepared by the
managing general partner without audit by independent public accountants.

   The accompanying notes are an integral part of these financial statements.



                                        5
   195

                          PARKER & PARSLEY 81-II, LTD.
                          (A Texas Limited Partnership)

                          NOTES TO FINANCIAL STATEMENTS
                                 March 31, 2001
                                   (Unaudited)

Note 1.  Organization and nature of operations

Parker & Parsley 81-II (the "Partnership") is a limited partnership organized in
1981 under the laws of the State of Texas.

The Partnership engages in oil and gas development and production in Texas and
is not involved in any industry segment other than oil and gas.

Note 2.  Basis of presentation

In the opinion of management, the unaudited financial statements of the
Partnership as of March 31, 2001 include all adjustments and accruals consisting
only of normal recurring accrual adjustments which are necessary for a fair
presentation of the results for the interim period. These interim results are
not necessarily indicative of results for a full year.

Certain information and footnote disclosure normally included in financial
statements prepared in accordance with generally accepted accounting principles
have been condensed or omitted in these interim financial statements. The
financial statements should be read in conjunction with the financial statements
and the notes thereto contained in the Partnership's report for the year ended
December 31, 2000, a copy of which is available upon request by writing to Rich
Dealy, Vice President and Chief Accounting Officer, 5205 North O'Connor
Boulevard, 1400 Williams Square West, Irving, Texas 75039-3746.

Management's Discussion and Analysis of Financial Condition and
     Results of Operations(1)

Results of Operations

Revenues:

The partnership's oil and gas revenues increased 54% to $108,066 for the three
months ended March 31, 2001 as compared to $70,001 for the same period in 2000.
The increase in revenues resulted from higher average prices received and an
increase in production. For the three months ended March 31, 2001, 2,169 barrels
of oil, 535 barrels of natural gas liquids ("NGLs") and 5,731 mcf of gas were
sold, or 3,659 barrel of oil equivalents ("BOEs"). For the three months ended
March 31, 2000, 2,052 barrels of oil, 685 barrels of NGLs and 1,489 mcf of gas
were sold, or 2,985 BOEs.



                                        6
   196

The average price received per barrel of oil increased $.52, or 2%, from $27.34
for the three months ended March 31, 2000 to $27.86 for the same period in 2001.
The average price received per barrel of NGLs increased $3.36, or 19%, from
$17.54 for the three months ended March 31, 2000 to $20.90 for the same period
in 2001. The average price received per mcf of gas increased 405% from $1.26
during the three months ended March 31, 2000 to $6.36 for the same period in
2001. The market price for oil and gas has been extremely volatile in the past
decade, and management expects a certain amount of volatility to continue in the
foreseeable future. The Partnership may therefore sell its future oil and gas
production at average prices lower or higher than that received during the three
months ended March 31, 2001.

Costs and Expenses:

Total costs and expenses increased to $65,952 for the three months ended March
31, 2001 as compared to $62,476 for the same period in 2000, an increase of
$3,476, or 6%. This increase was due to increases in production costs and
general and administrative expenses ("G&A"), offset by a decline in depletion.

Production costs were $50,840 for the three months ended March 31, 2001 and
$48,539 for the same period in 2000 resulting in a $2,301 increase, or 5%. The
increase was primarily due to higher production taxes of associated with higher
oil and gas prices.

G&A's components are independent accounting and engineering fees and managing
general partner personnel and administrative costs. During this period, G&A
increased 103% from $2,190 for the three months ended March 31, 2000 to $4,448
for the same period in 2001, primarily due to a higher percentage of the
managing general partner's G&A being allocated (limited to 3% of oil and gas
revenues) as a result of increased oil and gas revenues and an increase in the
accrual for tax preparation fees.

Depletion was $10,664 for the three months ended March 31, 2001 as compared to
$11,747 for the same period in 2000, a decrease of $1,083, or 9%. This decrease
was primarily due to a positive revision to proved reserves on one well during
the three months ended March 31, 2001.

Liquidity and Capital Resources

Net Cash Provided by Operating Activities

Net cash provided by operating activities increased $54,285 during the three
months ended March 31, 2001 from the same period ended March 31, 2000. This
increase was due to an increase in oil and gas sales receipts of $38,350 and a
reduction in working capital of $20,494, offset by increases in production costs
of $2,301 and G&A expenses of $2,258. The increase in oil and gas receipts
resulted from the increase in commodity prices during 2001 which contributed an
additional $11,234 to oil and gas receipts and $27,116 resulting from an
increase in production during 2001 as compared to the same period in 2000. The
increase in production costs was primarily due to increased production taxes
associated with higher oil and gas prices. The increase in G&A was primarily due
to a higher percentage of the managing general partner's G&A being allocated



                                        7
   197

(limited to 3% of oil and gas revenues) as a result of increased oil and gas
revenues and an increase in the accrual for tax preparation fees.

Net Cash Used in Investing Activities

For the three months ended March 31, 2001 and 2000, the Partnership's investing
activities included expenditures related to equipment upgrades on active oil and
gas properties.

Net Cash Used in Financing Activities

For the three months ended March 31, 2001, cash distributions to the partners
were $59,505, of which $15,215 was distributed to the general partners and
$44,290 to the limited partners. For the same period ended March 31, 2000, cash
distributions to the partners were $16,316, of which $3,363 was distributed to
the general partners and $12,953 to the limited partners.

Proposal to acquire partnerships

On April 17, 2001, Pioneer Natural Resources Company ("Pioneer") filed a
preliminary proxy statement/prospectus with the Securities and Exchange
Commission proposing an agreement and plan of merger among Pioneer, Pioneer
Natural Resources USA, Inc. ("Pioneer USA"), a wholly-owned subsidiary of
Pioneer, and the limited partners of 46 Parker & Parsley limited partnerships.
Each partnership that approves the agreement and plan of merger and the other
related merger proposals will merge with and into Pioneer USA, and the
partnership interests of each such partnership will be converted into the right
to receive cash and Pioneer common stock. Pioneer USA is the sole or managing
general partner of the partnerships. The Partnership is one of the 46 Parker &
Parsley limited partnerships being requested to approve the agreement and plan
of merger. The preliminary proxy statement/prospectus is non-binding and is
subject to, among other things, consideration of offers from third parties to
purchase any partnership or its assets, the majority approval of the limited
partnership interests in each partnership and the resolution of Securities and
Exchange Commission review comments. No solicitation will be made using
preliminary materials.

----------

(1)  "Management's Discussion and Analysis of Financial Condition and Results
     of Operations" contains forward looking statements that involve risks and
     uncertainties. Accordingly, no assurances can be given that the actual
     events and results will not be materially different than the anticipated
     results described in the forward looking statements.



                                        8
   198






                          PARKER & PARSLEY 81-II, LTD.
                          (A Texas Limited Partnership)


                              FINANCIAL STATEMENTS
                                      WITH
                          INDEPENDENT AUDITORS' REPORT


                           December 31, 2000 and 1999







   199




                          INDEPENDENT AUDITORS' REPORT



The Partners
Parker & Parsley 81-II, Ltd.
 (A Texas Limited Partnership):

We have audited the balance sheets of Parker & Parsley 81-II, Ltd. as of
December 31, 2000 and 1999, and the related statements of operations, partners'
capital and cash flows for each of the three years in the period ended December
31, 2000. These financial statements are the responsibility of the Partnership's
management. Our responsibility is to express an opinion on these financial
statements based on our audits.

We conducted our audits in accordance with auditing standards generally accepted
in the United States. Those standards require that we plan and perform the audit
to obtain reasonable assurance about whether the financial statements are free
of material misstatement. An audit includes examining, on a test basis, evidence
supporting the amounts and disclosures in the financial statements. An audit
also includes assessing the accounting principles used and significant estimates
made by management, as well as evaluating the overall financial statement
presentation. We believe that our audits provide a reasonable basis for our
opinion.

In our opinion, the financial statements referred to above present fairly, in
all material respects, the financial position of Parker & Parsley 81-II, Ltd. as
of December 31, 2000 and 1999, and the results of its operations and its cash
flows for each of the three years in the period ended December 31, 2000, in
conformity with accounting principles generally accepted in the United States.




                                           Ernst & Young LLP


Dallas, Texas
March 9, 2001



                                       2
   200



                          PARKER & PARSLEY 81-II, LTD.
                          (A Texas Limited Partnership)

                                 BALANCE SHEETS
                                   December 31





                                                         2000        1999
                                                     ----------   ---------
           ASSETS
           ------
                                                           
Current assets:
 Cash                                               $    29,376  $   30,160
 Accounts receivable - oil and gas sales                 64,821      27,908
                                                     ----------   ---------

      Total current assets                               94,197      58,068
                                                     ----------   ---------

Oil and gas properties - at cost, based on the
  successful efforts accounting method                5,345,296   5,338,113
Accumulated depletion                                (4,821,914) (4,776,074)
                                                     ----------   ---------


     Net oil and gas properties                         523,382     562,039
                                                     ----------   ---------

                                                       $617,579  $  620,107
                                                     ==========   =========

LIABILITIES AND PARTNERS' CAPITAL
---------------------------------
Current liabilities:
 Accounts payable - affiliate                       $     9,253  $   10,581

Partners' capital:
  General partners                                       61,405      58,558
  Limited partners (1,153 interests)                    546,921     550,968
                                                     ----------   ---------

                                                        608,326     609,526
                                                     ----------   ---------
                                                    $   617,579  $  620,107
                                                     ==========   =========




   The accompanying notes are an integral part of these financial statements.



                                       3
   201



                          PARKER & PARSLEY 81-II, LTD.
                          (A Texas Limited Partnership)

                            STATEMENTS OF OPERATIONS
                         For the years ended December 31






                                             2000        1999       1998
                                          --------    --------    --------
                                                        
Revenues:
  Oil and gas                            $ 387,180   $ 204,717   $ 209,110
  Interest                                   2,775       1,395       1,725
  Gain on disposition of assets                -           240         -
                                          --------    --------    --------

                                           389,955     206,352     210,835
                                          --------    --------    --------

Costs and expenses:
  Oil and gas production                   189,764     140,847     173,960
  General and administrative                13,791       9,864       7,867
  Impairment of oil and gas properties         -           -        30,131
  Depletion                                 45,840      49,409      95,466
                                          --------    --------    --------

                                           249,395     200,120     307,424
                                          --------    --------    --------

Net income (loss)                        $ 140,560   $   6,232   $ (96,589)
                                          ========    ========    ========

Allocation of net income (loss):
  General partners                       $  41,791   $   8,423   $  (5,308)
                                          ========    ========    ========

  Limited partners                       $  98,769   $  (2,191)  $ (91,281)
                                          ========    ========    ========

Net income (loss) per limited
  partnership interest                   $   85.66   $   (1.90)  $  (79.17)
                                          ========    ========    ========





   The accompanying notes are an integral part of these financial statements.



                                       4
   202



                         PARKER & PARSLEY 81-II, LTD.
                          (A Texas Limited Partnership)

                         STATEMENTS OF PARTNERS' CAPITAL






                                           General      Limited
                                           partners     partners    Total
                                          ---------    ---------  ---------
                                                          
Partners' capital at January 1, 1998      $ 76,354     $706,525   $782,879

   Distributions                           (11,831)     (34,220)   (46,051)

   Net loss                                 (5,308)     (91,281)   (96,589)
                                          ---------    ---------  ---------

Partners' capital at December 31, 1998      59,215      581,024    640,239

   Distributions                            (9,080)     (27,865)   (36,945)

   Net income (loss)                         8,423       (2,191)     6,232
                                          ---------    ---------  ---------

Partners' capital at December 31, 1999      58,558      550,968    609,526

   Distributions                           (38,944)    (102,816)  (141,760)

   Net income                               41,791       98,769    140,560
                                          ---------    ---------  ---------

Partners' capital at December 31, 2000    $ 61,405     $546,921   $608,326
                                          =========    =========  =========






   The accompanying notes are an integral part of these financial statements.



                                       5
   203



                          PARKER & PARSLEY 81-II, LTD.
                          (A Texas Limited Partnership)

                            STATEMENTS OF CASH FLOWS
                         For the years ended December 31






                                                      2000        1999        1998
                                                   ---------    ---------  ---------
                                                                 
Cash flows from operating activities:
  Net income (loss)                                $140,560     $ 6,232    $(96,589)
  Adjustments to reconcile net income (loss) to
   net cash provided by operating activities:
     Impairment of oil and gas properties               -           -        30,131
     Depletion                                       45,840      49,409      95,466
     Gain on disposition of assets                      -          (240)        -
  Changes in assets and liabilities:
     Accounts receivable                            (36,913)     (3,325)     15,443
     Accounts payable                                (1,328)      3,022      (3,482)
                                                   ---------    ---------  ---------

        Net cash provided by operating activities   148,159      55,098      40,969
                                                   ---------    ---------  ---------
Cash flows from investing activities:
  Additions to oil and gas properties                (7,183)     (4,254)     (8,322)
  Proceeds from asset dispositions                      -           690         -
                                                   ---------    ---------  ---------

        Net cash used in investing activities        (7,183)     (3,564)     (8,322)
                                                   ---------    ---------  ---------

Cash flows used in financing activities:
  Cash distributions to partners                   (141,760)    (36,945)    (46,051)
                                                   ---------    ---------  ---------

Net increase (decrease) in cash                        (784)     14,589     (13,404)
Cash at beginning of year                            30,160      15,571      28,975
                                                   ---------    ---------  ---------

Cash at end of year                                $ 29,376     $30,160    $ 15,571
                                                   =========    =========  =========




   The accompanying notes are an integral part of these financial statements.



                                       6
   204



                          PARKER & PARSLEY 81-II, LTD.
                          (A Texas Limited Partnership)

                          NOTES TO FINANCIAL STATEMENTS
                        December 31, 2000, 1999 and 1998


NOTE 1.     ORGANIZATION AND NATURE OF OPERATIONS

     Parker & Parsley 81-II (the "Partnership") is a limited partnership
organized in 1981 under the laws of the State of Texas. The Partnership's
general partners are Pioneer Natural Resources USA, Inc. ("Pioneer USA") and P&P
Employees 81-II, Ltd. ("EMPL"). The Partnership's managing general partner is
Pioneer USA.

     The Partnership engages in oil and gas development and production in Texas
and is not involved in any industry segment other than oil and gas.

NOTE 2.     SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

     A summary of the significant accounting policies consistently applied in
the preparation of the accompanying financial statements follows:

     Oil and gas properties - The Partnership utilizes the successful efforts
method of accounting for its oil and gas properties and equipment. Under this
method, all costs associated with productive wells and nonproductive development
wells are capitalized while nonproductive exploration costs are expensed.
Capitalized costs relating to proved properties are depleted using the
unit-of-production method on a property-by-property basis based on proved oil
(dominant mineral) reserves as evaluated by independent petroleum consultants.
The carrying amounts of properties sold or otherwise disposed of and the related
allowances for depletion are eliminated from the accounts and any gain or loss
is included in results of operations.

     Impairment of long-lived assets - In accordance with Statement of Financial
Accounting Standards No. 121, "Accounting for the Impairment of Long-Lived
Assets and for Long-Lived Assets to be Disposed Of" ("SFAS 121"), the
Partnership reviews its long-lived assets to be held and used on an individual
property basis, including oil and gas properties accounted for under the
successful efforts method of accounting, whenever events or circumstances
indicate that the carrying value of those assets may not be recoverable. An
impairment loss is indicated if the sum of the expected future cash flows is
less than the carrying amount of the assets. In this circumstance, the
Partnership recognizes an impairment loss for the amount by which the carrying
amount of the asset exceeds the estimated fair value of the asset.

     Use of estimates in the preparation of financial statements - Preparation
of the accompanying financial statements in conformity with generally accepted
accounting principles requires management to make estimates and assumptions that
affect the reported amounts of assets and liabilities and disclosure of
contingent assets and liabilities at the date of the financial statements and
the reported amounts of revenues and expenses during the reporting periods.
Actual results could differ from those estimates.

                                       7
   205

     Net income (loss) per limited partnership interest - The net income (loss)
per limited partnership interest is calculated by using the number of
outstanding limited partnership interests.

     Income taxes - A Federal income tax provision has not been included in the
financial statements as the income of the Partnership is included in the
individual Federal income tax returns of the respective partners.

     Statements of cash flows - For purposes of reporting cash flows, cash
includes depository accounts held by banks.

     General and administrative expenses - General and administrative expenses
are allocated in part to the Partnership by the managing general partner.
Allocated expenses are determined by the managing general partner based upon the
level of activity of the Partnership relative to the non-partnership activities
of the managing general partner. The method of allocation has been consistent
over the past several years with certain modifications incorporated to reflect
changes in Pioneer USA's overall business activities.

     Reclassifications - Certain reclassifications may have been made to the
1999 and 1998 financial statements to conform to the 2000 financial statement
presentations.

     Environmental - The Partnership is subject to extensive federal, state and
local environmental laws and regulations. These laws, which are constantly
changing, regulate the discharge of materials into the environment and may
require the Partnership to remove or mitigate the environmental effects of the
disposal or release of petroleum or chemical substances at various sites.
Environmental expenditures are expensed or capitalized depending on their future
economic benefit. Expenditures that relate to an existing condition caused by
past operations and that have no future economic benefits are expensed.
Liabilities for expenditures of a noncapital nature are recorded when
environmental assessment and/or remediation is probable, and the costs can be
reasonably estimated. Such liabilities are generally undiscounted unless the
timing of cash payments for the liability or component are fixed or reliably
determinable. No such liabilities have been accrued as of December 31, 2000.

     Revenue recognition - The Partnership uses the entitlements method of
accounting for oil, natural gas liquids ("NGLs") and natural gas revenues.

NOTE 3.    IMPAIRMENT OF LONG-LIVED ASSETS

     In accordance with SFAS 121, the Partnership reviews its proved oil and gas
properties for impairment whenever events and circumstances indicate a decline
in the recoverability of the carrying value of the Partnership's oil and gas
properties. The Partnership has estimated the expected future cash flows of its
oil and gas properties as of December 31, 2000, 1999 and 1998, based on proved
reserves, and compared such estimated future cash flows to the respective
carrying amount of the oil and gas properties to determine if the carrying
amounts were likely to be recoverable. For those proved oil and gas properties
for which the carrying amount exceeded the estimated future cash flows, an
impairment was determined to exist; therefore, the Partnership adjusted the
carrying amount of those oil and gas properties to their fair value as
determined by discounting their expected future cash flows at a discount rate
commensurate with the risks involved

                                       8
   206

in the industry. As a result, the Partnership recognized a non-cash impairment
provision of $30,131 related to its proved oil and gas properties during 1998.

NOTE 4.    INCOME TAXES

     The financial statement basis of the Partnership's net assets and
liabilities was $172,373 greater than the tax basis at December 31, 2000.

     The following is a reconciliation of net income (loss) per statements of
operations with the net income per Federal income tax returns for the years
ended December 31:




                                                           2000       1999     1998
                                                        ---------   -------- ---------

                                                                    
    Net income (loss) per statements of operations     $ 140,560    $ 6,232  $ (96,589)
    Depletion and depreciation provisions for tax
     reporting purposes less than amounts for
     financial reporting purposes                         41,011     44,867     91,653
    Impairment of oil and gas properties for
     financial reporting purposes                           -          -        30,131
    Other, net                                              (482)      (178)       454
                                                        ---------   -------- ---------

         Net income per Federal income tax returns      $181,089   $ 50,921   $ 25,649
                                                        =========   ======== =========



NOTE 5.     OIL AND GAS PRODUCING ACTIVITIES

The following is a summary of the costs incurred, whether capitalized or
expensed, related to the Partnership's oil and gas producing activities for the
years ended December 31:




                                                2000         1999           1998
                                             ---------     --------      ---------

                                                                
     Development costs                       $  7,183      $  4,254      $  8,322
                                             =========     ========      =========

     Capitalized oil and gas properties consist of the following:




                                                          2000           1999
                                                      ----------      ----------
                                                              
     Proved properties:
       Property acquisition costs                    $   210,548     $   210,548
       Completed wells and equipment                   5,134,748       5,127,565
                                                      ----------      ----------

                                                       5,345,296       5,338,113
     Accumulated depletion                            (4,821,914)     (4,776,074)



       Net oil and gas properties                    $   523,382    $    562,039
                                                      ==========      ==========






                                       9
   207



NOTE 6.     RELATED PARTY TRANSACTIONS

     Pursuant to the limited partnership agreement, the Partnership had the
following related party transactions with the managing general partner during
the years ended December 31:




                                                         2000          1999            1998
                                                       --------      --------        --------
                                                                           
    Payment of lease operating and supervision
     charges in accordance with standard industry
     operating agreements                              $ 75,129      $ 61,684        $ 82,817

    Reimbursement of general and administrative
     expenses                                          $ 11,615      $  6,142        $  6,273


     Pioneer USA, EMPL and the Partnership are parties to the Partnership
agreement. EMPL is a limited partnership in which Pioneer USA owns 80% and the
remaining portion is owned by former affiliates.

     The costs and revenues of the Partnership are allocated as follows:




                                                         General       Limited
                                                         partners      partners
                                                         --------      --------
                                                                 
   Revenues:
     Proceeds from property dispositions prior to cost
      recovery                                              10%          90%
     All other Partnership revenues                         25%          75%
   Costs and expenses:
     Lease acquisition costs, drilling and completion
      costs and all other costs                             10%          90%
     Operating costs, direct costs and general and
      administrative expenses                               25%          75%


NOTE 7.     OIL AND GAS INFORMATION (UNAUDITED)

     The following table presents information relating to the Partnership's
estimated proved oil and gas reserves at December 31, 2000, 1999 and 1998 and
changes in such quantities during the years then ended. All of the Partnership's
reserves are proved developed and located within the United States. The
Partnership's reserves are based on an evaluation prepared by Williamson
Petroleum Consultants, Inc., an independent petroleum consultant, using criteria
established by the Securities and Exchange Commission.


                                       10
   208





                                                    Oil and NGLs          Gas
                                                       (bbls)            (mcf)
                                                    ------------      ------------

                                                                
    Net proved reserves at January 1, 1998            203,263            321,961
    Revisions                                         (93,478)          (131,045)
    Production                                        (16,033)           (22,439)
                                                    ---------         ----------

    Net proved reserves at December 31, 1998           93,752            168,477
    Revisions                                         118,281            224,790
    Production                                        (13,232)           (19,167)
                                                    ---------         ----------
    Net proved reserves at December 31, 1999          198,801            374,100
    Revisions                                          18,015            (61,237)
    Production                                        (13,921)           (15,864)
                                                    ---------         ----------
    Net proved reserves at December 31, 2000          202,895            296,999
                                                    =========         ==========


     As of December 31, 2000, the estimated present value of future net revenues
of proved reserves, calculated using December 31, 2000 prices of $26.64 per
barrel of oil, $14.08 per barrel of NGLs and $7.91 per mcf of gas, discounted at
10% was approximately $1,416,000 and undiscounted was $2,636,000.

     Numerous uncertainties exist in estimating quantities of proved reserves
and future net revenues therefrom. The estimates of proved reserves and related
future net revenues set forth in this Report are based on various assumptions,
which may ultimately prove to be inaccurate. Therefore, such estimates should
not be construed as estimates of the current market value of the Partnership's
proved reserves. The Partnership emphasizes that reserve estimates are
inherently imprecise and, accordingly, the estimates are expected to change as
future information becomes available.

Disclosures about Oil & Gas Producing Activities

Standardized Measure of Discounted Future Net Cash Flows

    The standardized measure of discounted future net cash flows is computed by
applying year-end prices of oil and gas (with consideration of price changes
only to the extent provided by contractual arrangements) to the estimated future
production of proved oil and gas reserves less estimated future expenditures
(based on year-end costs) to be incurred in developing and producing the proved
reserves, discounted using a rate of 10% per year to reflect the estimated
timing of the future cash flows. A Federal income tax provision has not been
calculated as the income of the Partnership is included in the individual
Federal income tax returns of the respective partners.

    Discounted future cash flow estimates like those shown below are not
intended to represent estimates of the fair value of oil and gas properties.
Estimates of fair value should also consider anticipated future oil and gas
prices, interest rates, changes in development and production costs and risks
associated with future production. Because of these and other considerations,
any estimate of fair value is necessarily subjective and imprecise.









                                       11
   209





                                              For the years ended December 31,
                                              --------------------------------

                                                2000        1999       1998
                                              ---------  ----------  ---------
                                                      (in thousands)
                                                           
Oil and gas producing activities:
  Future cash inflows                         $  6,624   $   4,915   $  1,020
  Future production costs                       (3,988)     (3,116)      (849)
                                              --------   ---------   --------

                                                 2,636       1,799        171
  10% annual discount factor                    (1,220)       (799)       (47)
                                              --------   ---------   --------

  Standardized measure of discounted future
   net cash flows                             $  1,416   $   1,000   $    124
                                              ========   =========   ========







                                              For the years ended December 31,
                                              --------------------------------

                                                2000        1999       1998
                                              ---------  ----------  ---------
                                                      (in thousands)

                                                           
  Oil and Gas Producing Activities:
    Oil and gas sales, net of production costs  $ (197)  $    (64)  $     (35)
    Net changes in prices and production costs     530         471       (544)
    Revisions of previous quantity estimates        45         781        (94)
    Accretion of discount                          100          12         76
    Changes in production rates, timing and
      other                                        (62)       (324)       (40)
                                              --------   ---------   --------
    Change in present value of future net
      revenues                                     416         876       (637)
                                              --------   ---------   --------
    Balance, beginning of year                   1,000         124        761
                                                ------     -------     ------

    Balance, end of year                      $  1,416   $   1,000   $    124
                                               =======    ========    =======




NOTE 8.    MAJOR CUSTOMERS

     The following table reflects the major customers of the Partnership's oil
and gas sales (a major customer is defined as a customer whose sales exceed 10%
of total sales) during the years ended December 31:




                                                2000       1999        1998
                                              --------   --------    --------

                                                            
            Plains Marketing, L.P.              56%         48%         -
            LG&E Natural Marketing, Inc.        13%         17%        19%
            NGTS LLC                            11%         14%         -
            Western Gas Processing               2%          4%        13%
            Genesis Crude Oil, L.P.              4%          1%        43%


     At December 31, 2000, the amounts receivable from Plains Marketing, L.P.,
LG&E Natural Marketing, Inc. and NGTS LLC were $26,794, $10,707 and $4,029,
respectively, which are included in the caption "Accounts receivable - oil and
gas sales" in the accompanying Balance Sheet.

     Pioneer USA is of the opinion that the loss of any one purchaser would not
have an adverse effect on the ability of the Partnership to sell its oil, NGLs
and gas production.


                                       12
   210



NOTE 9.     PARTNERSHIP AGREEMENT

     The following is a brief summary of the more significant provisions of the
limited partnership agreement:

     General partners - The general partners of the Partnership are Pioneer USA
     and EMPL. Pioneer USA, the managing general partner, has the power and
     authority to manage, control and administer all Partnership affairs. As
     managing general partner and operator of the Partnership's properties, all
     production expenses are incurred by Pioneer USA and billed to the
     Partnership. The majority of the Partnership's oil and gas revenues are
     received directly by the Partnership, however, a portion of the oil and gas
     revenue is initially received by Pioneer USA prior to being paid to the
     Partnership.

     Limited partner liability - The maximum amount of liability of any limited
     partner is the total contributions of such partner plus his share of any
     undistributed profits.

     Initial capital contributions - The limited partners entered into
     subscription agreements for aggregate capital contributions of $5,765,000.
     During 1983, the Partnership received a total of $675,000 from its limited
     partnership in response to an assessment by the managing general partner.
     The general partners are required to contribute amounts equal to 10% of
     Partnership expenditures for lease acquisition, drilling and completion and
     25% of direct, general and administrative and operating expenses.



                                       13
   211

                          PARKER & PARSLEY 81-II, LTD.
                          (A TEXAS LIMITED PARTNERSHIP)

THIS REPORT CONTAINS FORWARD LOOKING STATEMENTS THAT INVOLVE RISKS AND
UNCERTAINTIES. ACCORDINGLY, NO ASSURANCES CAN BE GIVEN THAT THE ACTUAL EVENTS
AND RESULTS WILL NOT BE MATERIALLY DIFFERENT THAN THE ANTICIPATED RESULTS
DESCRIBED IN THE FORWARD LOOKING STATEMENTS.

MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND
  RESULTS OF OPERATIONS

Results of operations

2000 compared to 1999

The Partnership's oil and gas revenues increased 89% to $387,180 for 2000 as
compared to $204,717 in 1999. The increase in revenues resulted from higher
average prices received and a slight increase in production. In 2000, 8,885
barrels of oil, 5,036 barrels of natural gas liquids ("NGLs") and 15,864 mcf of
gas were sold, or 16,565 barrel of oil equivalents ("BOEs"). In 1999, 6,860
barrels of oil, 6,372 barrels of NGLs and 19,167 mcf of gas were sold, or 16,427
BOEs. Due to the decline characteristics of the Partnership's oil and gas
properties, management expects a certain amount of decline in production in the
future until the Partnership's economically recoverable reserves are fully
depleted.

The average price received per barrel of oil increased $12.59, or 76%, from
$16.67 in 1999 to $29.26 in 2000. The average price received per barrel of NGLs
increased $6.89, or 79%, from $8.70 in 1999 to $15.59 in 2000. The average price
received per mcf of gas increased 69% from $1.82 in 1999 to $3.07 in 2000. The
market price for oil and gas has been extremely volatile in the past decade, and
management expects a certain amount of volatility to continue in the foreseeable
future. The Partnership may therefore sell its future oil and gas production at
average prices lower or higher than that received in 2000.

Gain on disposition of assets of $240 was recognized during 1999 from equipment
credits received on one fully depleted well.

Total costs and expenses increased in 2000 to $249,395 as compared to $200,120
in 1999, an increase of $49,275, or 25%. The increase was primarily due to
increases in production costs and general and administrative expenses ("G&A"),
offset by a decline in depletion.

Production costs were $189,764 in 2000 and $140,847 in 1999, resulting in a
$48,917 increase, or 35%. The increase was primarily due to additional well
maintenance costs incurred to stimulate well production and higher production
taxes associated with higher oil and gas prices.

G&A's components are independent accounting and engineering fees and managing
general partner personnel and operating costs. During this period, G&A increased
40% from $9,864 in 1999 to $13,791 in 2000, primarily due to a higher percentage
of the managing general partner's G&A being allocated (limited to 3% of oil and
gas revenues) as a result of increased oil and gas revenues. The Partnership
paid the managing general partner $11,615 in 2000 and $6,142 in 1999 for G&A
incurred on behalf of the Partnership. The remaining G&A was paid directly by
the Partnership. The managing general partner determines the allocated expenses
based upon the level of activity of the Partnership relative to the
non-partnership activities of the managing general partner. The method of
allocation has been consistent over the past several years with certain
modifications incorporated to reflect changes in Pioneer USA's overall business
activities.

Depletion was $45,840 in 2000 as compared to $49,409 in 1999, representing a
decrease of $3,569, or 7%. This decrease was primarily due to an 18,828 barrels
of oil increase in proved reserves during 2000 as a result of higher commodity
prices, offset by an increase in oil production of 2,025 barrels for the period
ended December 31, 2000 compared to the same period in 1999.



   212


1999 compared to 1998

The Partnership's 1999 oil and gas revenues decreased 2% to $204,717 from
$209,110 in 1998. The decrease in revenues resulted from a decline in
production, offset by higher average prices received. In 1999, 6,860 barrels of
oil, 6,372 barrels of NGLs and 19,167 mcf of gas were sold, or 16,427 BOEs. In
1998, 9,451 barrels of oil, 6,582 barrels of NGLs and 22,439 mcf of gas were
sold, or 19,773 BOEs.

The average price received per barrel of oil increased $3.51, or 27%, from
$13.16 in 1998 to $16.67 in 1999. The average price received per barrel of NGLs
increased $1.97, or 29%, from $6.73 in 1998 to $8.70 in 1999. The average price
received per mcf of gas increased slightly from $1.80 in 1998 to $1.82 in 1999.

Gain on disposition of assets of $240 was recognized during 1999 from equipment
credits received on one fully depleted well.

Total costs and expenses decreased in 1999 to $200,120 as compared to $307,424
in 1998, a decrease of $107,304, or 35%. The decrease was primarily due to
declines in depletion, production costs and the impairment of oil and gas
properties, offset by an increase in G&A.

Production costs were $140,847 in 1999 and $173,960 in 1998, resulting in a
$33,113 decrease, or 19%. The decrease was due to declines in well maintenance
costs, ad valorem taxes and production taxes.

During this period, G&A increased 25% from $7,867 in 1998 to $9,864 in 1999
primarily due to a higher percentage of the managing general partner's G&A being
allocated (limited to 3% of oil and gas revenues) as a result of increased oil
and gas revenues. The Partnership paid the managing general partner $6,142 in
1999 and $6,273 in 1998 for G&A incurred on behalf of the Partnership.

In accordance with Statement of Financial Accounting Standards No. 121,
"Accounting for the Impairment of Long-Lived Assets and for Long-Lived Assets to
be Disposed Of" ("SFAS 121"), the managing general partner reviews the
Partnership's oil and gas properties for impairment whenever events or
circumstances indicate a decline in the recoverability of the carrying value of
the Partnership's assets may have occurred. As a result of the review and
evaluation of its long-lived assets for impairment, the Partnership recognized a
non-cash charge of $30,131 related to its oil and gas properties during 1998.

Depletion was $49,409 in 1999 compared to $95,466 in 1998, representing a
decrease of $46,057, or 48%. This decrease was the result of a combination of
factors that included an increase in proved reserves of 59,807 barrels of oil
during 1999 as a result of higher commodity prices, a decline in oil production
of 2,591 barrels for the period ended December 31, 1999 compared to the same
period in 1998 and a reduction in the Partnership's net depletable basis from
charges taken in accordance with SFAS 121 during the fourth quarter of 1998.

Petroleum Industry

The petroleum industry has been characterized by volatile oil, NGL and natural
gas commodity prices and relatively stable supplier costs during the three years
ended December 31, 2000. During 1998, weather patterns, regional economic
recessions and political matters combined to cause worldwide oil supplies to
exceed demand resulting in a substantial decline in oil prices. Also during
1998, but to a lesser extent, market prices for natural gas declined. During
1999 and 2000, the Organization of Petroleum Exporting Countries ("OPEC") and
certain other crude oil exporting nations announced reductions in their planned
export volumes. Those announcements, together with the enactment of the
announced reductions in export volumes, had a positive impact on world oil
prices, as have overall natural gas supply and demand fundamentals on North
American natural gas prices. Although the favorable commodity price environment
and stable field service cost environment is expected to continue during 2001,
there is no assurance that commodity prices will not return to a less favorable
level or that field service costs will not escalate in the future, both of which
could negatively impact the Partnership's future results of operations and cash
distributions.




   213


Liquidity and capital resources

Net Cash Provided by Operating Activities

Net cash provided by operating activities increased $93,061 during the year
ended December 31, 2000 from 1999. This increase was due to increases in oil and
gas sales receipts of $183,843, offset by increases in production costs paid of
$48,917, G&A expenses paid of $3,927 and working capital of $37,938. The
increase in oil and gas receipts resulted from the increase in commodity prices
during 2000 which contributed an additional $65,846 to oil and gas receipts and
$117,997 resulted from an increase in production during 2000. The increase in
production costs was primarily due to increased production taxes associated with
higher oil and gas prices and well maintenance costs incurred to stimulate well
production. The increase in G&A was primarily due to higher percentage of the
managing general partner's G&A being allocated (limited to 3% of oil and gas
revenues) as a result of increased oil and gas revenues.

Net Cash Used in Investing Activities

The Partnership's principal investing activities during 2000 and 1999 included
expenditures related to upgrades of equipment on various oil and gas properties.

Proceeds from asset dispositions of $690 were received during 1999 for the sale
of equipment on active properties.

Net Cash Used in Financing Activities

In 2000, cash distributions to the partners were $141,760, of which $38,944 was
distributed to the general partners and $102,816 to the limited partners. In
1999, cash distributions to the partners were $36,945, of which $9,080 was
distributed to the general partners and $27,865 to the limited partners.












   214



                          PARKER & PARSLEY 81-II, LTD.


SELECTED FINANCIAL DATA

The following selected financial data for the Partnership should be read in
connection with Management's Discussion and Analysis of Financial Condition and
Results of Operations and the financial statements included in the attached
supplemental information.



                                        Three months
                                            ended
                                          March 31,                       Years ended December 31,
                                   ---------------------   --------------------------------------------------------------
                                     2001        2000         2000         1999         1998         1997         1996
                                   --------   ----------   ----------   ----------   ----------   ----------   ----------
                                                                                          
  Oil and gas sales                $          $   70,001   $  387,180   $  204,717   $  209,110   $  311,922   $  363,398
                                   ========   ==========   ==========   ==========   ==========   ==========   ==========

  Impairment of oil and
    gas properties                 $          $       --   $       --   $       --   $   30,131   $   52,269   $       --
                                   ========   ==========   ==========   ==========   ==========   ==========   ==========

  Gain on litigation
      settlement, net              $          $       --   $       --   $       --   $       --   $       --   $    3,289
                                   ========   ==========   ==========   ==========   ==========   ==========   ==========

  Net income (loss)                $          $    7,922   $  140,560   $    6,232   $  (96,589)  $    9,511   $  113,519
                                   ========   ==========   ==========   ==========   ==========   ==========   ==========

  Allocation of net
    income (loss):
         Managing general
           partner                 $          $    3,743   $   41,791   $    8,423   $   (5,308)  $   24,620   $   37,637
                                   ========   ==========   ==========   ==========   ==========   ==========   ==========

         Limited partners          $          $    4,179   $   98,769   $   (2,191)  $  (91,281)  $  (15,109)  $   75,882
                                   ========   ==========   ==========   ==========   ==========   ==========   ==========

  Limited partners' net
    income (loss) per limited
    partnership interest           $          $     3.62   $    85.66   $    (1.90)  $   (79.17)  $   (13.10)  $    65.81
                                   ========   ==========   ==========   ==========   ==========   ==========   ==========

  Limited partners' cash
    distributions per limited
    partnership interest           $          $    11.23   $    89.17   $    24.17   $    29.68   $    93.49   $    89.30(a)
                                   ========   ==========   ==========   ==========   ==========   ==========   ==========

At year end:
  Total assets                     $          $  611,605   $  617,579   $  620,107   $  647,798   $  793,920   $  928,791
                                   ========   ==========   ==========   ==========   ==========   ==========   ==========


----------

(a)  Including litigation settlement per limited partnership interest of $2.85
     in 1996.



   215

                        PIONEER NATURAL RESOURCES COMPANY
                       PIONEER NATURAL RESOURCES USA, INC.
                            1400 WILLIAMS SQUARE WEST
                            5205 NORTH O'CONNOR BLVD.
                               IRVING, TEXAS 75039

                            SUPPLEMENTAL INFORMATION

                                       OF

            PARKER & PARSLEY 82-I, LTD., A TEXAS LIMITED PARTNERSHIP

                                       TO

                PROXY STATEMENT/PROSPECTUS DATED         , 2001

                                   ----------

                 THE DATE OF THIS SUPPLEMENT IS         , 2001

                                   ----------


     This document contains important information specific to Parker & Parsley
82-I, Ltd. and supplements the proxy statement/prospectus dated         , 2001,
of Pioneer Natural Resources Company and Pioneer Natural Resources USA, Inc.,
by which Pioneer USA is soliciting proxies to be voted at a special meeting of
limited partners of the partnership. The purpose of the special meeting is for
you to vote upon the merger of the partnership with and into Pioneer USA that,
if completed, will result in your receiving common stock of Pioneer Natural
Resources Company for your partnership interests.


     This document contains the following information concerning Parker &
Parsley 82-I, Ltd.:

     o   A table containing:

         --       the aggregate initial investment by the limited partners


         --       the aggregate historical limited partner distributions through
                  July 31, 2001

         --       the merger value attributable to partnership interests of
                  limited partners, excluding Pioneer USA

         --       the merger value per $1,000 limited partner investment

         --       the merger value per $1,000 limited partner investment as a
                  multiple of distributions for the past four quarterly
                  distributions including the distribution in July 2001


         --       the book value per $1,000 limited partner investment as of
                  March 31, 2001 and as of December 31, 2000


         --       the going concern value per $1,000 limited partner investment

         --       the liquidation value per $1,000 limited partner investment


         --       the ordinary tax loss per $1,000 limited partner investment in
                  year of initial investment

     o   Information about:


         --       the legal opinion for the limited partners

         --       the term of the partnership


     o   The partnership's quarterly report on Form 10-Q, including management's
         discussion and analysis of financial condition and results of
         operations, for the three months ended March 31, 2001

     o   The partnership's annual report on Form 10-K, including management's
         discussion and analysis of financial condition and results of
         operations, for the year ended December 31, 2000

     o   Selected historical financial data for the partnership for the three
         months ended March 31, 2001 and 2000 and the five years ended December
         31, 2000


                                      - 1-


   216


                           PARKER & PARSLEY 82-I, LTD.

                         SUPPLEMENTAL INFORMATION TABLE







                                                                                          
Aggregate Initial Investment by the Limited Partners(a)                                      $11,805

Aggregate Historical Limited Partner Distributions through July 31, 2001(a)                  $11,639

Merger Value Attributable to Partnership Interests of Limited Partners, Excluding Pioneer    $   844
USA(a),(b)

Merger Value per $1,000 Limited Partner Investment(b),(c)                                    $ 80.06

Merger Value per $1,000 Limited Partner Investment as a Multiple of Distributions for the       2.72 times
past four quarterly distributions including the distribution in July 2001(b),(c)

Book Value per $1,000 Limited Partner Investment:

     --  as of March 31, 2001(c)                                                             $ 22.31

     --  as of December 31, 2000(c)                                                          $ 23.71

Going Concern Value per $1,000 Limited Partner Investment(c),(d)                             $ 72.07

Liquidation Value per $1,000 Limited Partner Investment(c),(e)                               $ 77.68

Ordinary Tax Loss per $1,000 Limited Partner Investment in Year of Initial Investment        $   265
(c),(f)


----------

(a)  Stated in thousands.


(b)  The merger value for the partnership is equal to the sum of the present
     value of estimated future net revenues from the partnership's estimated oil
     and gas reserves and its net working capital, in each case as of March 31,
     2001, less its pro rata share, based on its reserve value, of the estimated
     expenses and fees of the mergers of all of the partnerships and less the
     cash distribution on or about July 9, 2001, by the partnership to its
     partners.

(c)  Interests in some partnerships were sold in units at prices other than
     $1,000. We have presented this information based on a $1,000 initial
     investment for ease of use and comparison among partnerships. You should
     not assume that the amount shown per $1,000 investment is the same as the
     value or amount attributable to a single unit investment.

(d)  The going concern value for the partnership is based upon: (1) the sum of
     (A) the estimated net cash flow from the sale of the partnership's reserves
     during a 10-year operating period and (B) the estimated residual value from
     the sale of the partnership's remaining reserves at the end of the
     operating period, in each case using the same pricing and discount rate as
     in the merger value calculation, less (2) partnership level general and
     administrative expenses.

(e)  The liquidation value for the partnership is based upon the sale of the
     partnership's reserves at the reserve value, less liquidation expenses
     which are estimated to be the sum of (1) the partnership's pro rata share
     of the merger expenses and fees described in footnote (b) above and (2) 3%
     of the partnership's reserve value. The liquidation expenses represent
     estimated costs to retain an investment banker or broker to sell the assets
     of the partnership and the legal and other closing costs associated with
     such transaction, including the wind-down costs of the partnership.

(f)  Your ability to use your distributive share of the partnership's loss to
     offset your other income may have been subject to certain limitations at
     your level as a partner, and you may therefore wish to consult your tax
     advisor to determine the additional value, if any, actually realized by you
     in your particular circumstances.


          INFORMATION ABOUT THE LEGAL OPINION FOR THE LIMITED PARTNERS

     The partnership agreement for the partnership requires that special legal
counsel render an opinion on behalf of the limited partners to Pioneer USA that
(1) neither the grant nor the exercise of the right to approve the merger of the
partnership by its limited partners will adversely affect the federal income tax
classification of the partnership or any of its limited partners; and (2)
neither the grant nor exercise of such right will result in the loss of any
limited partner's limited liability. In addition, the counsel designated to
render the opinion must be counsel other than counsel to Pioneer USA or the
partnership. Both the designated counsel and the legal opinion must be approved
by the limited partners. Pioneer USA has retained __________ of Dallas, Texas
for the purpose of rendering this legal opinion on behalf of the limited
partners to Pioneer USA. The merger proposals include an approval of that
counsel and the form of its opinion. A copy of the opinion is attached as an
exhibit to the merger proposals.


                  INFORMATION ABOUT THE TERM OF THE PARTNERSHIP

     The term of the partnership shall continue until terminated in accordance
with the applicable provisions of its partnership agreement.



                                     - 2 -
   217

                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D. C. 20549


                                    FORM 10-Q


                Quarterly Report Pursuant to Section 13 or 15(d)
                     of the Securities Exchange Act of 1934

                  For the quarterly period ended March 31, 2001

                          Commission File No. 2-75530A


                           PARKER & PARSLEY 82-1, LTD.
             (Exact name of Registrant as specified in its charter)


                       Texas                                 75-1825545
          ----------------------------------           ---------------------
           (State or other jurisdiction of                (I.R.S. Employer
           incorporation or organization)              Identification Number)


1400 Williams Square West, 5205 N. O'Connor Blvd., Irving, Texas       75039
----------------------------------------------------------------      -------
             (Address of principal executive offices)               (Zip code)


       Registrant's Telephone Number, including area code : (972) 444-9001

                                 Not applicable
              (Former name, former address and former fiscal year,
                          if changed since last report)


Indicate by check mark whether the Registrant (1) has filed all reports required
to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during
the preceding 12 months (or for such shorter period that the Registrant was
required to file such reports), and (2) has been subject to such filing
requirements for the past 90 days.

                                Yes [x]  No [ ]




   218



                           PARKER & PARSLEY 82-I, LTD.

                                TABLE OF CONTENTS




                                                                      Page

                                                                      
                          Part I. Financial Information

Item 1.     Financial Statements

            Balance Sheets as of March 31, 2001 and
               December 31, 2000 ....................................    3

            Statements of Operations for the three months
              ended March 31, 2001 and 2000..........................    4

            Statement of Partners' Capital for the three months
              ended March 31, 2001...................................    5

            Statements of Cash Flows for the three months
              ended March 31, 2001 and 2000..........................    6

            Notes to Financial Statements............................    7

Item 2.     Management's Discussion and Analysis of Financial
              Condition and Results of Operations....................    7


                           Part II. Other Information

Item 6.     Exhibits and Reports on Form 8-K.........................    9

            Signatures...............................................   10



                                        2

   219



                           PARKER & PARSLEY 82-I, LTD.
                          (A Texas Limited Partnership)

                          Part I. Financial Information

Item 1.      Financial Statements



                                 BALANCE SHEETS

                                                     March 31,      December 31,
                                                       2001            2000
                                                    -----------     -----------
                                                    (Unaudited)
                 ASSETS
                                                              
Current assets:
   Cash                                             $    52,030     $    57,728
   Accounts receivable - oil and gas sales              103,207         109,719
                                                    -----------     -----------
         Total current assets                           155,237         167,447
                                                    -----------     -----------
Oil and gas properties - at cost, based on the
   successful efforts accounting method               9,901,101       9,901,101
Accumulated depletion                                (9,619,512)     (9,613,644)
                                                    -----------     -----------
         Net oil and gas properties                     281,589         287,457
                                                    -----------     -----------
                                                    $   436,826     $   454,904
                                                    ===========     ===========
LIABILITIES AND PARTNERS' CAPITAL

Current liabilities:
   Accounts payable - affiliate                     $    16,407     $    13,712

Partners' capital:
   General partners                                     157,022         161,365
   Limited partners (4,891 interests)                   263,397         279,827
                                                    -----------     -----------
                                                        420,419         441,192
                                                    -----------     -----------
                                                    $   436,826     $   454,904
                                                    ===========     ===========



The financial information included as of March 31, 2001 has been prepared by the
managing general partner without audit by independent public accountants.

 The accompanying notes are an integral part of these financial statements.

                                        3

   220



                           PARKER & PARSLEY 82-I, LTD.
                          (A Texas Limited Partnership)

                            STATEMENTS OF OPERATIONS
                                   (Unaudited)




                                                   Three months ended
                                                        March 31,
                                                -------------------------
                                                   2001           2000
                                                ----------     ----------

                                                         
Revenues:
  Oil and gas                                   $  216,836     $  172,087
  Interest                                           1,229            973
                                                ----------     ----------
                                                   218,065        173,060
                                                ----------     ----------
Costs and expenses:
  Oil and gas production                            97,986         85,023
  General and administrative                         8,176          5,363
  Depletion                                          5,868          9,057
                                                ----------     ----------
                                                   112,030         99,443
                                                ----------     ----------
Net income                                      $  106,035     $   73,617
                                                ==========     ==========
Allocation of net income:
  General partners                              $   27,134     $   19,763
                                                ==========     ==========
  Limited partners                              $   78,901     $   53,854
                                                ==========     ==========
Net income per limited partnership interest     $    16.13     $    11.01
                                                ==========     ==========




         The financial information included herein has been prepared by the
managing general partner without audit by independent public accountants.

The accompanying notes are an integral part of these financial statements.

                                        4

   221



                           PARKER & PARSLEY 82-I, LTD.
                          (A Texas Limited Partnership)

                         STATEMENT OF PARTNERS' CAPITAL
                                   (Unaudited)





                                      General        Limited
                                      partners       partners         Total
                                     ----------     ----------      ----------

                                                           

Balance at January 1, 2001           $  161,365     $  279,827      $  441,192

    Distributions                       (31,477)       (95,331)       (126,808)

    Net income                           27,134         78,901         106,035
                                     ----------     ----------      ----------
Balance at March 31, 2001            $  157,022     $  263,397      $  420,419
                                     ==========     ==========      ==========







         The financial information included herein has been prepared by the
managing general partner without audit by independent public accountants.

The accompanying notes are an integral part of these financial statements.

                                        5

   222



                           PARKER & PARSLEY 82-I, LTD.
                          (A Texas Limited Partnership)

                            STATEMENTS OF CASH FLOWS
                                   (Unaudited)




                                                         Three months ended
                                                              March 31,
                                                       -----------------------
                                                          2001          2000
                                                       ---------     ---------

                                                               
Cash flows from operating activities:
  Net income                                           $ 106,035     $  73,617
  Adjustments to reconcile net income to net
    cash provided by operating activities:
      Depletion                                            5,868         9,057
  Changes in assets and liabilities:
      Accounts receivable                                  6,512       (17,930)
      Accounts payable                                     2,695         1,812
                                                       ---------     ---------
          Net cash provided by operating activities      121,110        66,556
                                                       ---------     ---------
Cash flows used in investing activities:
  Additions to oil and gas properties                         --          (110)

Cash flows used in financing activities:
  Cash distributions to partners                        (126,808)      (61,903)
                                                       ---------     ---------
Net increase (decrease) in cash                           (5,698)        4,543
Cash at beginning of period                               57,728        61,558
                                                       ---------     ---------
Cash at end of period                                  $  52,030     $  66,101
                                                       =========     =========





         The financial information included herein has been prepared by
the managing general partner without audit by independent public accountants.

The accompanying notes are an integral part of these financial statements.

                                        6

   223



                           PARKER & PARSLEY 82-I, LTD.
                          (A Texas Limited Partnership)

                          NOTES TO FINANCIAL STATEMENTS
                                 March 31, 2001
                                   (Unaudited)


Note 1.     Organization and nature of operations

Parker & Parsley 82-I, Ltd. (the "Partnership") is a limited partnership
organized in 1982 under the laws of the State of Texas.

The  Partnership  engages in oil and gas development and production in Texas and
is not involved in any industry segment other than oil and gas.

Note 2.     Basis of presentation

In the opinion of management, the unaudited financial statements of the
Partnership as of March 31, 2001 include all adjustments and accruals consisting
only of normal recurring accrual adjustments which are necessary for a fair
presentation of the results for the interim period. These interim results are
not necessarily indicative of results for a full year. Certain reclassifications
may have been made to the March 31, 2000 financial statements to conform to the
March 31, 2001 financial statement presentations.

Certain information and footnote disclosures normally included in financial
statements prepared in accordance with generally accepted accounting principles
have been condensed or omitted in this Form 10-Q pursuant to the rules and
regulations of the Securities and Exchange Commission. The financial statements
should be read in conjunction with the financial statements and the notes
thereto contained in the Partnership's Report on Form 10-K for the year ended
December 31, 2000, as filed with the Securities and Exchange Commission, a copy
of which is available upon request by writing to Rich Dealy, Vice President and
Chief Accounting Officer, 5205 North O'Connor Boulevard, 1400 Williams Square
West, Irving, Texas 75039-3746.

Item 2. Management's Discussion and Analysis of Financial Condition and Results
        of Operations (1)

Results of Operations

Revenues:

The Partnership's oil and gas revenues increased 26% to $216,836 for the three
months ended March 31, 2001 as compared to $172,087 for the same period in 2000.
The increase in revenues resulted from higher average prices received, offset by
a decrease in production. For the three months ended March 31, 2001, 4,462
barrels of oil, 856 barrels of natural gas liquids ("NGLs") and 13,274 mcf of

                                        7

   224



gas were sold, or 7,530 barrel of oil equivalents ("BOEs"). For the three months
ended March 31, 2000, 4,433 barrels of oil, 1,810 barrels of NGLs and 12,235 mcf
of gas were sold, or 8,282 BOEs.

The average price received per barrel of oil increased $.79, or 3%, from $27.23
for the three months ended March 31, 2000 to $28.02 for the same period in 2001.
The average price received per barrel of NGLs increased $7.01, or 55%, from
$12.67 for the three months ended March 31, 2000 to $19.68 for the same period
in 2001. The average price received per mcf of gas increased 143%, from $2.33
for the three months ended March 31, 2000 to $5.65 for the same period in 2001.
The market price for oil and gas has been extremely volatile in the past decade,
and management expects a certain amount of volatility to continue in the
foreseeable future. The Partnership may therefore sell its future oil and gas
production at average prices lower or higher than that received during the three
months ended March 31, 2001.

Costs and Expenses:

Total costs and expenses increased to $112,030 for the three months ended March
31, 2001 as compared to $99,443 for the same period in 2000, an increase of
$12,587, or 13%. This increase was primarily due to increases in production
costs and general and administrative expenses ("G&A"), offset by a decline in
depletion.

Production costs were $97,986 for the three months ended March 31, 2001 and
$85,023 for the same period in 2000 resulting in a $12,963 increase, or 15%. The
increase was primarily due to additional well maintenance costs incurred to
stimulate well production and higher production taxes associated with higher oil
and gas prices.

G&A's components are independent accounting and engineering fees and managing
general partner personnel and administrative costs. During this period, G&A
increased 52% from $5,363 for the three months ended March 31, 2000 to $8,176
for the same period in 2001 primarily due to a higher percentage of the managing
general partner's G&A being allocated (limited to 3% of oil and gas revenues) as
a result of increased oil and gas revenues and an increase in the accrual for
tax preparation fees.

Depletion was $5,868 for the three months ended March 31, 2001 as compared to
$9,057 for the same period in 2000, a decrease of $3,189, or 35%. This decrease
was primarily due to positive revisions to proved reserves during the three
months ended March 31, 2001 as a result of higher commodity prices.

Liquidity and Capital Resources

Net Cash Provided by Operating Activities

Net cash provided by operating activities increased $54,554 during the three
months ended March 31, 2001 from the same period in 2000. The increase was due
to an increase of $45,005 in oil and gas sales receipts and a reduction of
$25,325 in working capital, offset by increases in production costs of $12,963
and G&A expenses of $2,813. The increase in oil and gas receipts resulted from
the increase in commodity prices during 2001 which contributed an additional

                                        8

   225



$57,097 to oil and gas receipts, offset by $12,092 resulting from the decline in
production during 2001 as compared to the same period in 2000. The increase in
production costs was primarily due to additional well maintenance costs incurred
to stimulate well production and increased production taxes associated with
higher oil and gas prices. The increase in G&A was primarily due to a higher
percentage of the managing general partner's G&A being allocated (limited to 3%
of oil and gas revenues) as a result of increased oil and gas revenues and an
increase in the accrual for tax preparation fees.

Net Cash Used in Financing Activities

For the three months ended March 31, 2001, cash distributions to the partners
were $126,808, of which $31,477 was distributed to the general partners and
$95,331 to the limited partners. For the same period ended March 31, 2000, cash
distributions to the partners were $61,903, of which $15,492 was distributed to
the general partners and $46,411 to the limited partners.

Proposal to acquire partnerships

On April 17, 2001, Pioneer Natural Resources Company ("Pioneer") filed a
preliminary proxy statement/prospectus with the Securities and Exchange
Commission proposing an agreement and plan of merger among Pioneer, Pioneer
Natural Resources USA, Inc. ("Pioneer USA"), a wholly-owned subsidiary of
Pioneer, and the limited partners of 46 Parker & Parsley limited partnerships.
Each partnership that approves the agreement and plan of merger and the other
related merger proposals will merge with and into Pioneer USA, and the
partnership interests of each such partnership will be converted into the right
to receive cash and Pioneer common stock. Pioneer USA is the sole or managing
general partner of the partnerships. The Partnership is one of the 46 Parker &
Parsley limited partnerships being requested to approve the agreement and plan
of merger. The preliminary proxy statement/prospectus is non-binding and is
subject to, among other things, consideration of offers from third parties to
purchase any partnership or its assets, the majority approval of the limited
partnership interests in each partnership and the resolution of Securities and
Exchange Commission review comments. No solicitation will be made using
preliminary materials.

----------

(1)      "Item 2. Management's Discussion and Analysis of Financial Condition
         and Results of Operations" contains forward looking statements that
         involve risks and uncertainties. Accordingly, no assurances can be
         given that the actual events and results will not be materially
         different than the anticipated results described in the forward looking
         statements.

                           Part II. Other Information

Item 6.           Exhibits and Reports on Form 8-K

(a)     Exhibits - none

(b)     Reports on Form 8-K - none.


                                        9

   226


                           PARKER & PARSLEY 82-1, LTD.
                          (A Texas Limited Partnership)



                                   SIGNATURES



       Pursuant to the requirements of the Securities Exchange Act of 1934,  the
Registrant  has duly  caused  this  report  to be  signed  on its  behalf by the
undersigned thereunto duly authorized.


                                            PARKER & PARSLEY 82-1, LTD.

                                   By:      Pioneer Natural Resources USA, Inc.
                                             Managing General Partner



Dated:  May 8, 2001                By:      /s/ Rich Dealy
                                            ----------------------------------
                                            Rich Dealy, Vice President
                                              and Chief Accounting Officer


                                       10



   227
                UNITED STATES SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D. C. 20549

                                    FORM 10-K

                  Annual Report Pursuant to Section 13 or 15(d)
                     of the Securities Exchange Act of 1934

                   FOR THE FISCAL YEAR ENDED DECEMBER 31, 2000


                          COMMISSION FILE NO. 2-75530A


                           PARKER & PARSLEY 82-I, LTD.
             (Exact name of Registrant as specified in its charter)


                     TEXAS                             75-1825545
        -------------------------------         ----------------------
        (State or other jurisdiction of            (I.R.S. Employer
        incorporation or organization)          Identification Number)


1400 WILLIAMS SQUARE WEST, 5205 N. O'CONNOR BLVD., IRVING, TEXAS        75039
----------------------------------------------------------------      ----------
           (Address of principal executive offices)                   (Zip code)

       Registrant's Telephone Number, including area code: (972) 444-9001

        Securities registered pursuant to Section 12(b) of the Act: NONE
          Securities registered pursuant to Section 12(g) of the Act:
                 LIMITED PARTNERSHIP INTERESTS ($2,000 PER UNIT)
                 -----------------------------------------------

Indicate by check mark whether the Registrant (1) has filed all reports required
to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during
the preceding 12 months (or for such shorter period that the Registrant was
required to file such reports), and (2) has been subject to such filing
requirements for the past 90 days. YES / X / NO / /

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405
of Regulation S-K is not contained herein, and will not be contained, to the
best of Registrant's knowledge, in definitive proxy or information statements
incorporated by reference in Part III of this Form 10-K or any amendment to this
Form 10-K. / X /

No market currently exists for the limited partnership interests of the
Registrant. Based on the original purchase price, the aggregate market value of
limited partnership interests owned by non-affiliates of the Registrant is
$8,515,000.

       As of March 8, 2001, the number of outstanding limited partnership
                              interests was 4,891.

 The following documents are incorporated by reference into the indicated parts
                    of this Annual Report on Form 10-K: None

PARTS I AND II OF THIS ANNUAL REPORT ON FORM 10-K (THE "REPORT") CONTAIN FORWARD
LOOKING STATEMENTS THAT INVOLVE RISKS AND UNCERTAINTIES. ACCORDINGLY, NO
ASSURANCES CAN BE GIVEN THAT THE ACTUAL EVENTS AND RESULTS WILL NOT BE
MATERIALLY DIFFERENT THAN THE ANTICIPATED RESULTS DESCRIBED IN THE FORWARD
LOOKING STATEMENTS. SEE "ITEM 1. BUSINESS" FOR A DESCRIPTION OF VARIOUS FACTORS
THAT COULD MATERIALLY AFFECT THE ABILITY OF THE PARTNERSHIP TO ACHIEVE THE
ANTICIPATED RESULTS DESCRIBED IN THE FORWARD LOOKING STATEMENTS.

   228

                                     PART I

ITEM 1.  BUSINESS

Parker & Parsley 82-I, Ltd. (the "Partnership") is a limited partnership
organized in 1982 under the laws of the State of Texas. The Partnership's
managing general partner is Pioneer Natural Resources USA, Inc. ("Pioneer USA")
and its co-general partner is P&P Employees 82-I, Ltd. ("EMPL"), a Texas limited
partnership whose general partner is Pioneer USA. Pioneer USA is a wholly-owned
subsidiary of Pioneer Natural Resources Company ("Pioneer"). As of March 8,
2001, the Partnership had 4,891 limited partnership interests outstanding.

The Partnership does not have any employees of its own. Pioneer USA employs 701
persons, many of whom dedicated a part of their time to the conduct of the
Partnership's business during the period for which this Report is filed. Pioneer
USA supplies all management functions.

The Partnership engages in oil and gas development and production and is not
involved in any industry segment other than oil and gas. The Partnership's
production is geographically concentrated in West Texas.

The principal markets during 2000 for the oil produced by the Partnership were
refineries and oil transmission companies that have facilities near the
Partnership's oil producing properties. During 2000, Pioneer USA marketed the
Partnership's gas to a variety of purchasers. Of the Partnership's total oil and
gas revenues for 2000, approximately 68% and 13% were attributable to sales made
to Plains Marketing, L.P. and GPM Gas Corporation, respectively. Pioneer USA is
of the opinion that the loss of any one purchaser would not have an adverse
effect on its ability to sell its oil, natural gas liquids ("NGLs") and gas
production.

The Partnership's revenues, profitability, cash flow and future rate of growth
are highly dependent on the prevailing prices of oil and gas, which are affected
by numerous factors beyond the Partnership's control. Oil and gas prices
historically have been very volatile. A substantial or extended decline in the
prices of oil or gas could have a material adverse effect on the Partnership's
revenues, profitability and cash flow and could, under certain circumstances,
result in a reduction in the carrying value of the Partnership's oil and gas
properties.

Oil and gas production operations are subject to various types of regulations by
local, state and federal agencies. The Partnership's operations are also subject
to state conservation laws and regulations, including the establishment of
maximum rates of production from wells and the regulation of spacing, plugging
and abandonment of wells. Each state generally imposes a production or severance
tax with respect to production and sale of oil and gas within their respective
jurisdictions. Noncompliance with the laws and regulations may subject the
Partnership to penalties, damages or other liabilities and compliance may
increase the cost of the Partnership's operations.


                                       2
   229

The oil and gas business is also subject to environmental hazards such as oil
spills, gas leaks and ruptures and discharges of toxic substances or gases that
could expose the Partnership to substantial liability due to pollution and other
environmental damages. Although the Partnership believes that its business
operations do not impair environmental quality and that its costs of complying
with any applicable environmental regulations are not currently significant, the
Partnership cannot predict what, if any, effect these environmental regulations
may have on its current or future operations.

Numerous uncertainties exist in estimating quantities of proved reserves and
future net revenues therefrom. The estimates of proved reserves and related
future net revenues set forth in this Report are based on various assumptions,
which may ultimately prove to be inaccurate. Therefore, such estimates should
not be construed as estimates of the current market value of the Partnership's
proved reserves.

No material part of the Partnership's business is seasonal and the Partnership
conducts no foreign operations.

ITEM 2.  PROPERTIES

The Partnership's properties consist of leasehold interests in properties on
which oil and gas wells are located. Such property interests are often subject
to landowner royalties, overriding royalties and other oil and gas leasehold
interests.

Fractional working interests in developmental and exploratory oil and gas
prospects located in Texas and New Mexico were acquired by the Partnership,
resulting in the Partnership's participation in the drilling of 34 oil and gas
wells. There were six dry holes from previous periods, two wells plugged and
abandoned and nine wells sold. At December 31, 2000, 17 wells were producing.

For information relating to the Partnership's estimated proved oil and gas
reserves at December 31, 2000, 1999 and 1998 and changes in such quantities for
the years then ended, see Note 7 of Notes to Financial Statements included in
"Item 8. Financial Statements and Supplementary Data" below. Such reserves have
been evaluated by Williamson Petroleum Consultants, Inc., an independent
petroleum consultant.

ITEM 3.  LEGAL PROCEEDINGS

The Partnership from time to time is a party to various legal proceedings
incidental to its business involving claims in oil and gas leases or interests,
other claims for damages in amounts not in excess of 10% of its current assets
and other matters, none of which Pioneer USA believes to be material to the
Partnership.

ITEM 4.  SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS

There were no matters submitted to a vote of the partners during the fourth
quarter of 2000.


                                       3
   230

                                     PART II

ITEM 5.  MARKET FOR LIMITED PARTNERSHIP INTERESTS AND LIMITED PARTNERSHIP
           DISTRIBUTIONS

At March 8, 2001, the Partnership had 4,891 outstanding limited partnership
interests held of record by 600 subscribers. There is no established public
trading market for the limited partnership interests. Under the limited
partnership agreement, Pioneer USA has made certain commitments to purchase
partnership interests at a computed value.

Revenues which, in the sole judgement of the managing general partner, are not
required to meet the Partnership's obligations are distributed to the partners
at least quarterly in accordance with the limited partnership agreement. During
the years ended December 31, 2000 and 1999, distributions of $229,765 and
$50,502, respectively, were made to the limited partners.

ITEM 6.  SELECTED FINANCIAL DATA

The following table sets forth selected financial data for the years ended
December 31:



                                   2000           1999           1998           1997         1996
                               ------------   ------------   ------------   ------------   ----------
                                                                            
Operating results:
-----------------
 Oil and gas sales             $    763,858   $    441,997   $    392,883   $    608,207   $  710,173
                               ============   ============   ============   ============   ==========

 Gain on litigation
   settlement, net             $         --   $         --   $         --   $         --   $   43,618
                               ============   ============   ============   ============   ==========

 Impairment of oil and gas
   properties                  $         --   $         --   $    294,610   $    165,201   $    2,277
                               ============   ============   ============   ============   ==========

 Net income (loss)             $    337,729   $     17,320   $   (563,993)  $    (60,847)  $  312,582
                               ============   ============   ============   ============   ==========

 Allocation of net income
   (loss):
     General partners          $     88,128   $     18,135   $    (49,472)  $     31,736   $   92,811
                               ============   ============   ============   ============   ==========

     Limited partners          $    249,601   $       (815)  $   (514,521)  $    (92,583)  $  219,771
                               ============   ============   ============   ============   ==========

 Limited partners' net
   income (loss) per limited
   partnership interest        $      51.03   $       (.17)  $    (105.20)  $     (18.93)  $    44.93
                               ============   ============   ============   ============   ==========

 Limited partners' cash
   distributions per limited
   partnership interest        $      46.98   $      10.33   $      19.57   $      47.31   $    51.40(a)
                               ============   ============   ============   ============   ==========

At year end:
-----------
 Identifiable assets           $    454,904   $    425,107   $    474,528   $  1,158,135   $1,526,765
                               ============   ============   ============   ============   ==========


---------------

(a) Including litigation settlement per limited partnership interest of $6.96 in
    1996.


                                       4
   231

ITEM 7.  MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS
           OF OPERATIONS

Results of operations

2000 compared to 1999

The Partnership's oil and gas revenues increased 73% to $763,858 for 2000 as
compared to $441,997 in 1999. The increase in revenues resulted from higher
average prices received, offset by a decline in production. In 2000, 17,639
barrels of oil, 6,519 barrels of natural gas liquids ("NGLs") and 45,981 mcf of
gas were sold, or 31,822 barrel of oil equivalents ("BOEs"). In 1999, 17,472
barrels of oil, 6,414 barrels of NGLs and 48,380 mcf of gas were sold, or 31,949
BOEs. Due to the decline characteristics of the Partnership's oil and gas
properties, management expects a certain amount of decline in production in the
future until the Partnership's economically recoverable reserves are fully
depleted.

The average price received per barrel of oil increased $12.78, or 77%, from
$16.61 in 1999 to $29.39 in 2000. The average price received per barrel of NGLs
increased $5.48, or 61%, from $8.96 in 1999 to $14.44 in 2000. The average price
received per mcf of gas increased 69% from $1.95 in 1999 to $3.29 in 2000. The
market price for oil and gas has been extremely volatile in the past decade and
management expects a certain amount of volatility to continue in the foreseeable
future. The Partnership may therefore sell its future oil and gas production at
average prices lower or higher than that received in 2000.

Total costs and expenses increased in 2000 to $431,421 as compared to $427,526
in 1999, an increase of $3,895, or 1%. The increase was due to increases in
production costs and general and administrative expenses ("G&A"), offset by a
decline in depletion.

Production costs were $378,872 in 2000 and $313,158 in 1999, resulting in an
increase of $65,714, or 21%. The increase was primarily due to additional well
maintenance costs incurred to stimulate well production and higher production
taxes associated with higher oil and gas prices.

G&A's components are independent accounting and engineering fees and managing
general partner personnel and operating costs. During this period, G&A increased
39% from $18,932 in 1999 to $26,409 in 2000 primarily due to a higher percentage
of the managing general partner's G&A being allocated (limited to 3% of oil and
gas revenues) as a result of increased oil and gas revenues. The Partnership
paid the managing general partner $22,916 in 2000 and $13,260 in 1999 for G&A
incurred on behalf of the Partnership. The remaining G&A was paid directly by
the Partnership. The managing general partner determines the allocated expenses
based upon the level of activity of the Partnership relative to the
non-partnership activities of the managing general partner. The method of
allocation has been consistent over the past several years with certain
modifications incorporated to reflect changes in Pioneer USA's overall business
activities.

Depletion was $26,140 in 2000 as compared to $95,436 in 1999, representing a
decrease of $69,296, or 73%. This decrease was primarily due to a 86,555 barrels
of oil increase in proved reserves during 2000 as a result of higher commodity
prices.

1999 compared to 1998

The Partnership's 1999 oil and gas revenues increased 13% to $441,997 from
$392,883 in 1998. The increase in revenues resulted from higher average prices
received, offset by a decline in production. In 1999, 17,472 barrels of oil,
6,414 barrels of NGLs and 48,380 mcf of gas were sold, or 31,949 BOEs. In 1998,
19,150 barrels of oil, 6,748 barrels of NGLs and 48,971 mcf of gas were sold, or
34,060 BOEs.


                                       5
   232

The average price received per barrel of oil increased $3.29, or 25%, from
$13.32 in 1998 to $16.61 in 1999. The average price received per barrel of NGLs
increased $1.76, or 24%, from $7.20 in 1998 to $8.96 in 1999. The average price
received per mcf of gas increased 7% from $1.82 in 1998 to $1.95 in 1999.

A gain on disposition of assets of $199 was recognized during 1998 from post
closing adjustments received from the sale of eight oil and gas wells during
1997.

Total costs and expenses decreased in 1999 to $427,526 as compared to $961,319
in 1998, a decrease of $533,793, or 56%. The decrease was primarily due to
declines in the impairment of oil and gas properties, depletion and production
costs, offset by an increase in G&A expenses.

Production costs were $313,158 in 1999 and $336,406 in 1998, resulting in a
$23,248 decrease, or 7%. The decrease was due to declines in well maintenance
costs and ad valorem taxes.

During this period, G&A increased 30% from $14,542 in 1998 to $18,932 in 1999
primarily due to a higher percentage of the managing general partner's G&A being
allocated (limited to 3% of oil and gas revenues) as a result of increased oil
and gas revenues. The Partnership paid the managing general partner $13,260 in
1999 and $11,786 in 1998 for G&A incurred on behalf of the Partnership.

In accordance with Statement of Financial Accounting Standards No. 121,
"Accounting for the Impairment of Long-Lived Assets and for Long-Lived Assets to
be Disposed Of" ("SFAS 121"), the managing general partner reviews the
Partnership's oil and gas properties for impairment whenever events or
circumstances indicate a decline in the recoverability of the carrying value of
the Partnership's assets may have occurred. As a result of the review and
evaluation of its long-lived assets for impairment, the Partnership recognized a
non-cash charge of $294,610 related to its oil and gas properties during 1998.

Depletion was $95,436 in 1999 compared to $315,761 in 1998, representing a
decrease of $220,325, or 70%. This decrease was the result of an increase in
proved reserves of 168,752 barrels of oil during 1999 as a result of higher
commodity prices and a reduction in the Partnership's net depletable basis from
charges taken in accordance with SFAS 121 during the fourth quarter of 1998.


Petroleum industry

The petroleum industry has been characterized by volatile oil, NGL and natural
gas commodity prices and relatively stable supplier costs during the three years
ended December 31, 2000. During 1998, weather patterns, regional economic
recessions and political matters combined to cause worldwide oil supplies to
exceed demand resulting in a substantial decline in oil prices. Also during
1998, but to a lesser extent, market prices for natural gas declined. During
1999 and 2000, the Organization of Petroleum Exporting Countries ("OPEC") and
certain other crude oil exporting nations announced reductions in their planned
export volumes. Those announcements, together with the enactment of the
announced reductions in export volumes, had a positive impact


                                       6
   233

on world oil prices, as have overall natural gas supply and demand fundamentals
on North American natural gas prices. Although the favorable commodity price
environment and stable field service cost environment is expected to continue
during 2001, there is no assurance that commodity prices will not return to a
less favorable level or that field service costs will not escalate in the
future, both of which could negatively impact the Partnership's future results
of operations and cash distributions.

Liquidity and capital resources

Net Cash Provided by Operating Activities

Net cash provided by operating activities increased $227,133 during the year
ended December 31, 2000 from 1999. This increase was due to an increase in oil
and gas sales receipts of $324,304, offset by increases in production costs paid
of $65,714, G&A expenses paid of $7,477 and working capital of $23,980. The
increase in oil and gas receipts resulted from the increase in commodity prices
during 2000 which contributed an additional $325,772 to oil and gas receipts,
offset by $1,468 resulting from the decline in production during 2000. The
increase in production costs was primarily due to increased production taxes
associated with higher oil and gas prices and well maintenance costs incurred to
stimulate well production. The increase in G&A was primarily due to higher
percentage of the managing general partner's G&A being allocated (limited to 3%
of oil and gas revenues) as a result of increased oil and gas revenues.

Net Cash Provided by (Used in) Investing Activities

The Partnership's principle investing activities during 2000 and 1999 were
related to the upgrades of oil and gas equipment on various oil and gas
properties.

Proceeds from asset dispositions of $704 in 1999 were from equipment credits
received on active properties.

Net Cash Used in Financing Activities

In 2000, cash distributions to the partners were $308,330, of which $78,565 was
distributed to the general partners and $229,765 to the limited partners. In
1999, cash distributions to the partners were $67,767, of which $17,265 was
distributed to the general partners and $50,502 to the limited partners.


                                       7
   234

ITEM 8.  FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA


                          INDEX TO FINANCIAL STATEMENTS



                                                                         Page
                                                                         ----
                                                                      
Financial Statements of Parker & Parsley 82-I, Ltd:
 Independent Auditors' Report............................................  9
 Balance Sheets as of December 31, 2000 and 1999......................... 10
 Statements of Operations for the Years Ended December 31,
   2000, 1999 and 1998................................................... 11
 Statements of Partners' Capital for the Years Ended
   December 31, 2000, 1999 and 1998...................................... 12
 Statements of Cash Flows for the Years Ended December 31,
   2000, 1999 and 1998................................................... 13
 Notes to Financial Statements........................................... 14



                                       8
   235

                          INDEPENDENT AUDITORS' REPORT



The Partners
Parker & Parsley 82-I, Ltd.
(A Texas Limited Partnership):

We have audited the balance sheets of Parker & Parsley 82-I, Ltd. as of December
31, 2000 and 1999, and the related statements of operations, partners' capital
and cash flows for each of the three years in the period ended December 31,
2000. These financial statements are the responsibility of the Partnership's
management. Our responsibility is to express an opinion on these financial
statements based on our audits.

We conducted our audits in accordance with auditing standards generally accepted
in the United States. Those standards require that we plan and perform the audit
to obtain reasonable assurance about whether the financial statements are free
of material misstatement. An audit includes examining, on a test basis, evidence
supporting the amounts and disclosures in the financial statements. An audit
also includes assessing the accounting principles used and significant estimates
made by management, as well as evaluating the overall financial statement
presentation. We believe that our audits provide a reasonable basis for our
opinion.

In our opinion, the financial statements referred to above present fairly, in
all material respects, the financial position of Parker & Parsley 82-I, Ltd. as
of December 31, 2000 and 1999, and the results of its operations and its cash
flows for each of the three years in the period ended December 31, 2000, in
conformity with accounting principles generally accepted in the United States.



                                                     Ernst & Young LLP


Dallas, Texas
March 9, 2001


                                       9
   236

                           PARKER & PARSLEY 82-I, LTD.
                          (A Texas Limited Partnership)

                                 BALANCE SHEETS
                                   December 31




                                                     2000           1999
                                                 -----------    -----------
                                                          
              ASSETS
              ------

Current assets:
 Cash                                            $    57,728    $    61,558
 Accounts receivable - oil and gas sales             109,719         61,533
                                                 -----------    -----------

       Total current assets                          167,447        123,091
                                                 -----------    -----------

Oil and gas properties - at cost, based on the
 successful efforts accounting method              9,901,101      9,889,520
Accumulated depletion                             (9,613,644)    (9,587,504)
                                                 -----------    -----------

       Net oil and gas properties                    287,457        302,016
                                                 -----------    -----------

                                                 $   454,904    $   425,107
                                                 ===========    ===========

LIABILITIES AND PARTNERS' CAPITAL
---------------------------------

Current liabilities:
 Accounts payable - affiliate                    $    13,712    $    13,314

Partners' capital:
 General partners                                    161,365        151,802
 Limited partners (4,891 interests)                  279,827        259,991
                                                 -----------    -----------

                                                     441,192        411,793
                                                 -----------    -----------

                                                 $   454,904    $   425,107
                                                 ===========    ===========



   The accompanying notes are an integral part of these financial statements.


                                       10
   237

                           PARKER & PARSLEY 82-I, LTD.
                          (A Texas Limited Partnership)

                            STATEMENTS OF OPERATIONS
                         For the years ended December 31




                                               2000        1999         1998
                                            ---------   ---------    ---------
                                                            
Revenues:
  Oil and gas                               $ 763,858   $ 441,997    $ 392,883
  Interest                                      5,292       2,849        4,244
  Gain on disposition of assets                    --          --          199
                                            ---------   ---------    ---------

                                              769,150     444,846      397,326
                                            ---------   ---------    ---------

Costs and expenses:
  Oil and gas production                      378,872     313,158      336,406
  General and administrative                   26,409      18,932       14,542
  Impairment of oil and gas properties             --          --      294,610
  Depletion                                    26,140      95,436      315,761
                                            ---------   ---------    ---------

                                              431,421     427,526      961,319
                                            ---------   ---------    ---------

Net income (loss)                           $ 337,729   $  17,320    $(563,993)
                                            =========   =========    =========

Allocation of net income (loss):
  General partners                          $  88,128   $  18,135    $ (49,472)
                                            =========   =========    =========

  Limited partners                          $ 249,601   $    (815)   $(514,521)
                                            =========   =========    =========

Net income (loss) per limited partnership
  interest                                  $   51.03   $    (.17)   $ (105.20)
                                            =========   =========    =========



   The accompanying notes are an integral part of these financial statements.


                                       11
   238

                           PARKER & PARSLEY 82-I, LTD.
                          (A Texas Limited Partnership)

                         STATEMENTS OF PARTNERS' CAPITAL




                                            General          Limited
                                            partners         partners           Total
                                           -----------      -----------      -----------

                                                                    
Partners' capital at January 1, 1998       $   221,119      $   921,541      $ 1,142,660

  Distributions                                (20,715)         (95,712)        (116,427)

  Net loss                                     (49,472)        (514,521)        (563,993)
                                           -----------      -----------      -----------

Partners' capital at December 31, 1998         150,932          311,308          462,240

  Distributions                                (17,265)         (50,502)         (67,767)

  Net income (loss)                             18,135             (815)          17,320
                                           -----------      -----------      -----------

Partners' capital at December 31, 1999         151,802          259,991          411,793

  Distributions                                (78,565)        (229,765)        (308,330)

  Net income                                    88,128          249,601          337,729
                                           -----------      -----------      -----------

Partners' capital at December 31, 2000     $   161,365      $   279,827      $   441,192
                                           ===========      ===========      ===========



   The accompanying notes are an integral part of these financial statements.


                                       12
   239

                           PARKER & PARSLEY 82-I, LTD.
                          (A Texas Limited Partnership)

                            STATEMENTS OF CASH FLOWS
                         For the years ended December 31




                                                      2000          1999          1998
                                                    ---------     ---------     ---------
                                                                       
Cash flows from operating activities:
 Net income (loss)                                  $ 337,729     $  17,320     $(563,993)
 Adjustments to reconcile net income (loss) to
   net cash provided by operating activities:
     Impairment of oil and gas properties                  --            --       294,610
     Depletion                                         26,140        95,436       315,761
     Gain on disposition of assets                         --            --          (199)
 Changes in assets and liabilities:
   Accounts receivable                                (48,186)      (24,834)       26,999
   Accounts payable                                       398         1,026        (3,187)
                                                    ---------     ---------     ---------

       Net cash provided by operating activities      316,081        88,948        69,991
                                                    ---------     ---------     ---------

Cash flows from investing activities:
 Additions to oil and gas properties                  (11,581)       (4,754)       (6,820)
 Proceeds from asset dispositions                          --           704        14,397
                                                    ---------     ---------     ---------

       Net cash provided by (used in)
          investing activities                        (11,581)       (4,050)        7,577
                                                    ---------     ---------     ---------

Cash flows used in financing activities:
 Cash distributions to partners                      (308,330)      (67,767)     (116,427)
                                                    ---------     ---------     ---------

Net increase (decrease) in cash                        (3,830)       17,131       (38,859)
Cash at beginning of year                              61,558        44,427        83,286
                                                    ---------     ---------     ---------

Cash at end of year                                 $  57,728     $  61,558     $  44,427
                                                    =========     =========     =========



   The accompanying notes are an integral part of these financial statements.


                                       13
   240

                           PARKER & PARSLEY 82-I, LTD.
                          (A Texas Limited Partnership)

                          NOTES TO FINANCIAL STATEMENTS
                        December 31, 2000, 1999 and 1998


NOTE 1.  ORGANIZATION AND NATURE OF OPERATIONS

        Parker & Parsley 82-I, Ltd. (the "Partnership") is a limited partnership
organized in 1982 under the laws of the State of Texas. The Partnership's
general partners are Pioneer Natural Resources USA, Inc. ("Pioneer USA") and P&P
Employees 82-I, Ltd. ("EMPL"). The Partnership's managing general partner is
Pioneer USA.

        The Partnership engages in oil and gas development and production in
Texas and is not involved in any industry segment other than oil and gas.

NOTE 2.  SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

        A summary of the significant accounting policies consistently applied in
the preparation of the accompanying financial statements follows:

        Oil and gas properties - The Partnership utilizes the successful efforts
method of accounting for its oil and gas properties and equipment. Under this
method, all costs associated with productive wells and nonproductive development
wells are capitalized while nonproductive exploration costs are expensed.
Capitalized costs relating to proved properties are depleted using the
unit-of-production method on a property-by-property basis based on proved oil
(dominant mineral) reserves as evaluated by independent petroleum consultants.
The carrying amounts of properties sold or otherwise disposed of and the related
allowances for depletion are eliminated from the accounts and any gain or loss
is included in results of operations.

        Impairment of long-lived assets - In accordance with Statement of
Financial Accounting Standards No. 121, "Accounting for the Impairment of
Long-Lived Assets and for Long-Lived Assets to be Disposed Of" ("SFAS 121"), the
Partnership reviews its long-lived assets to be held and used on an individual
property basis, including oil and gas properties accounted for under the
successful efforts method of accounting, whenever events or circumstances
indicate that the carrying value of those assets may not be recoverable. An
impairment loss is indicated if the sum of the expected future cash flows is
less than the carrying amount of the assets. In this circumstance, the
Partnership recognizes an impairment loss for the amount by which the carrying
amount of the asset exceeds the estimated fair value of the asset.

        Use of estimates in the preparation of financial statements -
Preparation of the accompanying financial statements in conformity with
generally accepted accounting principles requires management to make estimates
and assumptions that affect the reported amounts of assets and liabilities and
disclosure of contingent assets and liabilities at the date of the financial
statements and the reported amounts of revenues and expenses during the
reporting periods. Actual results could differ from those estimates.


                                       14
   241

        Net income (loss) per limited partnership interest - The net income
(loss) per limited partnership interest is calculated by using the number of
outstanding limited partnership interests.

        Income taxes - A Federal income tax provision has not been included in
the financial statements as the income of the Partnership is included in the
individual Federal income tax returns of the respective partners.

        Statements of cash flows - For purposes of reporting cash flows, cash
includes depository accounts held by banks.

        General and administrative expenses - General and administrative
expenses are allocated in part to the Partnership by the managing general
partner. Allocated expenses are determined by the managing general partner based
upon the level of activity of the Partnership relative to the non-partnership
activities of the managing general partner. The method of allocation has been
consistent over the past several years with certain modifications incorporated
to reflect changes in Pioneer USA's overall business activities.

        Reclassifications - Certain reclassifications may have been made to the
1999 and 1998 financial statements to conform to the 2000 financial statement
presentations.

        Environmental - The Partnership is subject to extensive federal, state
and local environmental laws and regulations. These laws, which are constantly
changing, regulate the discharge of materials into the environment and may
require the Partnership to remove or mitigate the environmental effects of the
disposal or release of petroleum or chemical substances at various sites.
Environmental expenditures are expensed or capitalized depending on their future
economic benefit. Expenditures that relate to an existing condition caused by
past operations and that have no future economic benefits are expensed.
Liabilities for expenditures of a noncapital nature are recorded when
environmental assessment and/or remediation is probable, and the costs can be
reasonably estimated. Such liabilities are generally undiscounted unless the
timing of cash payments for the liability or component are fixed or reliably
determinable. No such liabilities have been accrued as of December 31, 2000.

        Revenue recognition - The Partnership uses the entitlements method of
accounting for oil, natural gas liquids ("NGLs") and natural gas revenues.

NOTE 3.  IMPAIRMENT OF LONG-LIVED ASSETS

        In accordance with SFAS 121, the Partnership reviews its proved oil and
gas properties for impairment whenever events and circumstances indicate a
decline in the recoverability of the carrying value of the Partnership's oil and
gas properties. The Partnership has estimated the expected future cash flows of
its oil and gas properties as of December 31, 2000, 1999 and 1998, based on
proved reserves, and compared such estimated future cash flows to the respective
carrying amount of the oil and gas properties to determine if the carrying
amounts were likely to be recoverable. For those proved oil and gas properties
for which the carrying amount exceeded the estimated future cash flows, an
impairment was determined to exist; therefore, the Partnership adjusted the
carrying amount of those oil and gas properties to their fair value as
determined by discounting their expected future cash flows at a discount rate
commensurate with the risks involved in the industry. As a result, the
Partnership recognized a non-cash impairment provision of $294,610 related to
its proved oil and gas properties during 1998.


                                       15
   242

NOTE 4.  INCOME TAXES

        The financial statement basis of the Partnership's net assets and
liabilities was $663,714 less than the tax basis at December 31, 2000.

        The following is a reconciliation of net income (loss) per statements of
operations with the net income per Federal income tax returns for the years
ended December 31:



                                                         2000          1999         1998
                                                      ---------     ---------    ---------

                                                                        
Net income (loss) per statements of operations        $ 337,729     $  17,320    $(563,993)
Depletion and depreciation provisions for
 tax reporting purposes less than amounts for
 financial reporting purposes                            21,746        92,542      312,201
Impairment of oil and gas properties for financial
 reporting purposes                                          --            --      294,610
Loss on disposition of assets                                --            --         (116)
Other, net                                                 (637)           77          786
                                                      ---------     ---------    ---------
        Net income per Federal income tax
          returns                                     $ 358,838     $ 109,939    $  43,488
                                                      =========     =========    =========


NOTE 5.  OIL AND GAS PRODUCING ACTIVITIES

        The following is a summary of the costs incurred, whether capitalized or
expensed, related to the Partnership's oil and gas producing activities for the
years ended December 31:



                        2000         1999      1998
                     ---------    ---------    ------

                                      
Development costs    $  11,581    $   4,754    $6,820
                     =========    =========    ======


        Capitalized oil and gas properties consist of the following:



                                        2000            1999
                                    -----------     -----------
                                              
Proved properties:
 Property acquisition costs         $   360,899     $   360,899
 Completed wells and equipment        9,540,202       9,528,621
                                    -----------     -----------

                                      9,901,101       9,889,520
Accumulated depletion                (9,613,644)     (9,587,504)
                                    -----------     -----------

      Net oil and gas properties    $   287,457     $   302,016
                                    ===========     ===========


NOTE 6.  RELATED PARTY TRANSACTIONS

        Pursuant to the limited partnership agreement, the Partnership had the
following related


                                       16
   243

party transactions with the managing general partner during the years ended
December 31:



                                                 2000        1999        1998
                                               --------    --------    --------
                                                              
Payment of lease operating and supervision
  charges in accordance with standard
  industry operating agreements                $162,023    $156,380    $150,391

Reimbursement of general and administrative
  expenses                                     $ 22,916    $ 13,260    $ 11,786


        Pioneer USA, EMPL and the Partnership are parties to the Partnership
agreement. EMPL is a limited partnership in which Pioneer USA owns 77.5% and the
remaining portion is owned by former affiliates. In addition, Pioneer USA owned
634 limited partner interests at January 1, 2001.

        The costs and revenues of the Partnership are allocated as follows:



                                                         General       Limited
                                                         partners      partners
                                                         --------      --------
                                                                 
Revenues:
  Proceeds from property dispositions prior to cost
    recovery                                                10%           90%
  All other Partnership revenues                            25%           75%
Costs and expenses:
  Lease acquisition costs, drilling and completion costs    10%           90%
  Operating costs, direct costs and general and
    administrative expenses                                 25%           75%


NOTE 7.  OIL AND GAS INFORMATION (UNAUDITED)

        The following table presents information relating to the Partnership's
estimated proved oil and gas reserves at December 31, 2000, 1999 and 1998 and
changes in such quantities during the years then ended. All of the Partnership's
reserves are proved developed and located within the United States. The
Partnership's reserves are based on an evaluation prepared by Williamson
Petroleum Consultants, Inc., an independent petroleum consultant, using criteria
established by the Securities and Exchange Commission.



                                              Oil and NGLs          Gas
                                                 (bbls)            (mcf)
                                              ------------       --------
                                                           
Net proved reserves at January 1, 1998           321,477          448,047
Revisions                                       (230,755)        (305,609)
Production                                       (25,898)         (48,971)
                                                --------         --------



                                       17
   244


                                                           
Net proved reserves at December 31, 1998          64,824           93,467
Revisions                                        280,613          443,568
Production                                       (23,886)         (48,380)
                                                --------         --------

Net proved reserves at December 31, 1999         321,551          488,655
Revisions                                         60,464          362,471
Production                                       (24,158)         (45,981)
                                                --------         --------

Net proved reserves at December 31, 2000         357,857          805,145
                                                ========         ========


        As of December 31, 2000, the estimated present value of future net
revenues of proved reserves, calculated using December 31, 2000 prices of $26.55
per barrel of oil, $13.69 per barrel of NGLs and $8.68 per mcf of gas,
discounted at 10% was approximately $3,226,000 and undiscounted was $6,208,000.

        Numerous uncertainties exist in estimating quantities of proved reserves
and future net revenues therefrom. The estimates of proved reserves and related
future net revenues set forth in this Report are based on various assumptions,
which may ultimately prove to be inaccurate. Therefore, such estimates should
not be construed as estimates of the current market value of the Partnership's
proved reserves. The Partnership emphasizes that reserve estimates are
inherently imprecise and, accordingly, the estimates are expected to change as
future information becomes available.

Disclosures about Oil & Gas Producing Activities

Standardized Measure of Discounted Future Net Cash Flows

        The standardized measure of discounted future net cash flows is computed
by applying year-end prices of oil and gas (with consideration of price changes
only to the extent provided by contractual arrangements) to the estimated future
production of proved oil and gas reserves less estimated future expenditures
(based on year-end costs) to be incurred in developing and producing the proved
reserves, discounted using a rate of 10% per year to reflect the estimated
timing of the future cash flows. A Federal income tax provision has not been
calculated as the income of the Partnership is included in the individual
Federal income tax returns of the respective partners.

        Discounted future cash flow estimates like those shown below are not
intended to represent estimates of the fair value of oil and gas properties.
Estimates of fair value should also consider anticipated future oil and gas
prices, interest rates, changes in development and production costs and risks
associated with future production. Because of these and other considerations,
any estimate of fair value is necessarily subjective and imprecise.



                                                                 For the years ended December 31,
                                                               ------------------------------------
                                                                 2000          1999          1998
                                                               --------      --------      --------

                                                                          (in thousands)
                                                                                  
Oil and gas producing activities:
  Future cash inflows                                          $ 15,230      $  8,078      $    701



                                       18
   245


                                                                                  
  Future production costs                                        (9,022)       (5,386)         (624)
                                                               --------      --------      --------

                                                                  6,208         2,692            77
  10% annual discount factor                                     (2,982)       (1,056)          (11)
                                                               --------      --------      --------

  Standardized measure of discounted future net cash flows     $  3,226      $  1,636      $     66
                                                               ========      ========      ========