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                                                                    EXHIBIT 5.1

October 24, 2002

Plains Exploration & Production Company
Plains E&P Company
500 Dallas, Suite 700
Houston, Texas 77002

Re:  Plains Exploration & Production Company
    Plains E&P Company
    Registration Statement on Form S-4

Ladies and Gentlemen:

    We have acted as counsel to Plains Exploration & Production Company, a
Delaware corporation, and Plains E&P Company, a Delaware corporation (together,
the "Companies"), in connection with the registration, pursuant to a
registration statement on Form S-4, as amended (the "Registration Statement"),
filed with the Securities and Exchange Commission under the Securities Act of
1933, as amended (the "Act"), of (i) the proposed offer by the Companies to
exchange (the "Exchange Offer") all outstanding 83/4% Series A Senior
Subordinated Notes due 2012 (the "Outstanding Notes") of the Companies for
83/4% Series B Senior Subordinated Notes due 2012 (the "Registered Notes") of
the Companies and (ii) the guarantees (the "Guarantees") of the Subsidiary
Guarantors listed in the Registration Statement (the "Guarantors"). The
Outstanding Notes have been, and the Registered Notes will be, issued pursuant
to an Indenture (the "Indenture") dated July 3, 2002 among the Companies,
Arguello Inc., Plains Illinois Inc., Plains Resources International Inc., PMCT
Inc., and JPMorgan Chase Bank, as Trustee (the "Trustee"). We have examined
originals or certified copies of such corporate records of the Companies and
the Guarantors and other certificates and documents of officials of the
Companies and the Guarantors, public officials and others as we have deemed
appropriate for purposes of this letter. We have assumed the genuineness of all
signatures, the authenticity of all documents submitted to us as originals, and
the conformity to authentic original documents of all copies submitted to us as
conformed and certified or reproduced copies. We have also assumed the legal
capacity of natural persons, the corporate or other power of all persons
signing on behalf of the parties thereto other than the Companies, the due
authorization, execution and delivery of all documents by the parties thereto
other than the Companies, that the Registered Notes will conform to the
specimens examined by us and that the Trustee's certificate of authentication
of Registered Notes will be manually signed by one of the Trustee's authorized
officers.

    Based upon the foregoing and subject to the assumptions, exceptions,
qualifications and limitations set forth hereinafter, we are of the opinion
that when (a) the Registration Statement has become effective under the Act,
(b) the Outstanding Notes have been exchanged in the manner described in the
prospectus forming a part of the Registration Statement, (c) the Registered
Notes have been duly executed, authenticated, issued and delivered in
accordance with the terms of the Indenture, against receipt of the Outstanding
Notes surrendered in exchange therefor, (d) the Indenture has been duly
qualified under the Trust Indenture Act of 1939, as amended, and (e) applicable
provisions of "blue sky" laws have been complied with,

    1.  the Registered Notes proposed to be issued pursuant to the Exchange
        Offer, when duly executed, authenticated and delivered by or on behalf
        of the Companies, will be valid and binding obligations of the
        Companies and will be entitled to the benefits of the Indenture; and

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Plains Exploration & Production Company
Plains E&P Company
Page 2
October 24, 2002


    2.  the Guarantees proposed to be issued pursuant to the Exchange Offer
        will be valid and binding obligations of each Guarantor.

    The opinions and other matters in this letter are qualified in their
entirety and subject to the following:

    A.  We express no opinion as to the laws of any jurisdiction other than any
        published constitutions, treaties, laws, rules or regulations or
        judicial or administrative decisions ("Laws") of the state of New York
        and the General Corporation Law of the state of Delaware.

    B.  This law firm is a registered limited liability partnership organized
        under the laws of the state of Texas.

    C.  The matters expressed in this letter are subject to and qualified and
        limited by: (i) applicable bankruptcy, insolvency, fraudulent transfer
        and conveyance, reorganization, moratorium and similar Laws affecting
        creditors' rights and remedies generally; (ii) general principles of
        equity, including principles of commercial reasonableness, good faith
        and fair dealing (regardless of whether enforcement is sought in a
        proceeding at law or in equity); (iii) commercial reasonableness and
        unconscionability and an implied covenant of good faith and fair
        dealing; (iv) the power of the courts to award damages in lieu of
        equitable remedies; (v) securities Laws and public policy underlying
        such Laws with respect to rights to indemnification and contribution;
        and (vi) limitations on the waiver of rights under any stay, extension
        or usury Law or other Law, whether now or hereafter in force, which
        would prohibit or forgive the Companies or a Guarantor from paying all
        or any portion of the Outstanding or the Registered Notes as
        contemplated in the Indenture.

    We hereby consent to the filing of copies of this opinion as an exhibit to
the Registration Statement and to the use of our name in the prospectus forming
a part of the Registration Statement under the caption "Validity of the Series
B Notes." In giving this consent, we do not thereby admit that we are within
the category of persons whose consent is required under Section 7 of the Act
and the rules and regulations thereunder. This opinion speaks as of its date,
and we undertake no (and hereby disclaim any) obligation to update this opinion.

                                          Very truly yours,

                                          /S/ AKIN GUMP STRAUSS HAUER & FELD LLP