<PAGE>

                                                                    EXHIBIT 99.1

                                  [Proxy Card]

                     PLAINS EXPLORATION & PRODUCTION COMPANY

             PROXY FOR ANNUAL MEETING OF STOCKHOLDERS -- JUNE 3, 2003

                    THIS PROXY IS SOLICITED ON BEHALF OF THE
           PLAINS EXPLORATION & PRODUCTION COMPANY BOARD OF DIRECTORS

     The undersigned appoints James C. Flores and John T. Raymond, and each of
them, as proxies with power of substitution in each, to represent the
undersigned and to vote all the shares of common stock of Plains Exploration &
Production Company (the "Company") that the undersigned may be entitled to vote
at the Annual Meeting to be held in Houston, Texas on Tuesday, June 3, 2003 in
the manner shown on this form as to the following matters and in their
discretion on any other business or matters as may properly come before the
meeting or any adjournment(s) or postponement(s) thereof, including an
adjournment for the purpose of soliciting additional proxies.

     PLEASE MARK THIS PROXY AS INDICATED ON THE REVERSE SIDE TO VOTE ON ANY
ITEM. THIS PROXY WHEN PROPERLY EXECUTED WILL BE VOTED IN THE MANNER DIRECTED ON
THE REVERSE SIDE, OR IF NO SUCH DIRECTION IS INDICATED ON THE REVERSE SIDE, IN
ACCORDANCE WITH THE RECOMMENDATION OF THE BOARD OF DIRECTORS ON EACH PROPOSAL.

                   (CONTINUED AND TO BE SIGNED ON OTHER SIDE)


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

                              FOLD AND DETACH HERE


                   PLAINS EXPLORATION & PRODUCTION COMPANY

                   PLEASE MARK YOUR VOTES AS IN THE EXAMPLE.

                                      [x]


--------------------------------------------------------------------------------
  The Company's Board of Directors recommends a vote FOR proposals 1 through 4.
--------------------------------------------------------------------------------

1.   Proposal to approve the issuance of Company common stock to the
     stockholders of 3TEC Energy Corporation as a result of the transactions
     contemplated by the Agreement and Plan of Merger dated February 2, 2003, by
     and among the Company, its wholly-owned subsidiary PXP Gulf Coast Inc. and
     3TEC Energy Corporation pursuant to which 3TEC will be merged with and into
     PXP Gulf Coast;

     FOR   [ ]           AGAINST   [ ]             ABSTAIN   [ ]


2.   Proposal to Approve the Company's 2002 Stock Incentive Plan;

     FOR   [ ]           AGAINST   [ ]             ABSTAIN   [ ]


3.   Proposal to Approve adjustment to the Company's 2002 Stock Incentive Plan
     to increase the number of shares of Plains common stock reserved for
     issuance under the plan to 1.5 million shares if the merger occurs; and

     FOR   [ ]           AGAINST   [ ]             ABSTAIN   [ ]


4.   Election of Directors to serve until their successors are duly elected and
     qualified or until their earlier death, resignation or removal.

     FOR the nominees             WITHHOLD AUTHORITY
      listed below              for all nominees below
          [ ]                            [ ]

Nominees:  James C. Flores                  (INSTRUCTION: to withhold authority
           Alan R. Buckwalter, III           to vote for the nominee(s),
           Jerry L. Dees                     write the nominee's name in the
           Tom H. Delimitros                 space provided below entitled
           John H. Lollar                    "Exceptions".)

Exceptions:_____________________________________________________________________

--------------------------------------------------------------------------------
            The Audit Committee of the Company's Board of Directors
                      recommends a vote "FOR" proposal 5.
--------------------------------------------------------------------------------

5.   Proposal to ratify the selection of PricewaterhouseCoopers LLP as the
     Company's independent auditors for the fiscal year ending December 31,
     2003.

     FOR   [ ]           AGAINST   [ ]             ABSTAIN   [ ]

<PAGE>


                                     I hereby revoke any proxy or proxies
                                     previously given to represent or vote the
                                     shares of common stock of the Company that
                                     I am entitled to vote, and I ratify and
                                     confirm all actions that the proxies, their
                                     substitutes, or any of them, may lawfully
                                     take in accordance with the terms of this
                                     proxy card.


                            Dated:                                        , 2003




                                     Signature(s) of Stockholder(s)

                    Please sign this proxy as your name(s) appears above. Joint
                    owners should both sign. If signed as attorney, executor,
                    guardian or in some other representative capacity, or as
                    officer of a corporation, please indicate your capacity or
                    title.

                    Please complete, date and sign this proxy and return it
                    promptly in the enclosed envelope, which requires no postage
                    if mailed in the United States.