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                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                  SCHEDULE 13D

                    UNDER THE SECURITIES EXCHANGE ACT OF 1934
                               (AMENDMENT NO. 15)*

                             PLAINS RESOURCES, INC.
    ........................................................................
                                (Name of Issuer)

                                  COMMON STOCK
    ........................................................................
                         (Title of Class of Securities)

                                    726540503
    ........................................................................
                                 (CUSIP Number)

         DAVID J. SHLADOVSKY, C/O KAYNE ANDERSON CAPITAL ADVISORS, L.P.
          1800 AVENUE OF THE STARS, SECOND FLOOR, LOS ANGELES, CA 90067

                                 (310) 556-2721
    ........................................................................
                  (Name, Address and Telephone Number of Person
                Authorized to Receive Notices and Communications)

                                     7/12/04
    ........................................................................
             (Date of Event which Requires Piling of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report
the acquisition that is the subject of this Schedule 13D, and is filing this
schedule because of Rule 13d-1(e), 13d-1(f) or 13d-1(g), check the following box
[ ].

Note: Schedules filed in paper format shall include a signed original and five
copies of the schedule, including all exhibits. See Rule 13d-7(b) for other
parties to whom copies are to be sent.

*The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter
disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934 ("Act") or otherwise subject to the liabilities of that section of the Act
but shall be subject to all other provisions of the Act (however, see the
Notes).






CUSIP NO. 726540503

                             SCHEDULE 13D                      PAGE 2 OF 7 PAGES

..............................................................................
 1      NAME OF REPORTING PERSON
        S.S. or I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

        RICHARD A. KAYNE                                  - 124-34-0063
..............................................................................
 2      CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP                 (a) [ ]
                                                                         (b) [X]
..............................................................................
 3      SEC USE ONLY
..............................................................................
  4     SOURCE OF FUNDS

        AF PF
..............................................................................
 5      CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT
        TO ITEMS 2(d) or 2(E)                                                [ ]
..............................................................................
 6      CITIZENSHIP OR PLACE OF ORGANIZATION

        A U.S. CITIZEN
..............................................................................
                              7     SOLE VOTING POWER

NUMBER OF                           80,616
SHARES                       ................................................
BENEFICIALLY                  8     SHARED VOTING POWER
OWNED BY
EACH REPORTING                      1,662,650
PERSON WITH                  ................................................
                              9     SOLE DISPOSITIVE POWER

                                    80,616
                             ................................................
                             10     SHARED DISPOSITIVE POWER

                                    1,662,650
..............................................................................
11      AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

        1,743,266
..............................................................................
12      CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN
        SHARES                                                               [ ]

..............................................................................
13      PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 11

        7.1%
..............................................................................
12      TYPE OF REPORTING PERSON

        IN
..............................................................................


CUSIP NO. 726540503             SCHEDULE 13D                   PAGE 3 OF 7 PAGES



..............................................................................
 1      NAME OF REPORTING PERSON
        S.S. or I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

        KAYNE ANDERSON CAPITAL ADVISORS, L.P.             - 95-4486379

..............................................................................
 2      CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP                 (a) [ ]
                                                                         (b) [X]
..............................................................................
 3      SEC USE ONLY
..............................................................................
  4     SOURCE OF FUNDS

        AF PF
..............................................................................
 5      CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT
        TO ITEMS 2(d) or 2(E)                                                [ ]
..............................................................................
 6      CITIZENSHIP OR PLACE OF ORGANIZATION

        A CALIFORNIA LIMITED PARTNERSHIP
..............................................................................
                              7     SOLE VOTING POWER

NUMBER OF                           0
SHARES                       ................................................
BENEFICIALLY                  8     SHARED VOTING POWER
OWNED BY
EACH REPORTING                       1,662,650
PERSON WITH                  ................................................
                              9     SOLE DISPOSITIVE POWER

                                    0
                             ................................................
                             10     SHARED DISPOSITIVE POWER

                                    1,662,650
..............................................................................
11      AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

        1,662,650
..............................................................................
12      CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN
        SHARES                                                               [ ]

..............................................................................
13      PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 11

        6.8%
..............................................................................
12      TYPE OF REPORTING PERSON

        IA
..............................................................................



4
                                  United States
                       Securities and Exchange Commission

                                  SCHEDULE 13D
                                AMENDMENT NO. 15
*********************

ITEM 1.  SECURITY AND ISSUER

Common Stock, $0.10 par value.

        Plains Resources, Inc.
        700 Milam Street, Suite 3100
        Houston, TX  77002

ITEM 2.  IDENTITY AND BACKGROUND

The Reporting Persons include Kayne Anderson Capital Advisors, L.P. and Richard
A. Kayne and the investment partnerships and limited liability company
identified in the next paragraph.

a.      KAYNE ANDERSON CAPITAL ADVISORS, L.P.

        Kayne Anderson Capital Advisors, L.P. ("KACALP"), a California limited
        partnership, is an investment adviser registered with the Securities and
        Exchange Commission under the Investment Advisers Act of 1940. It serves
        as sole general partner of and investment adviser to various investment
        partnerships holding the issuer's Common Stock. KACALP also serves as
        investment adviser to a small number of separate account clients which
        hold the issuer's Common Stock.

        Kayne Anderson Investment Management, Inc. ("KAIM"), a Nevada
        corporation, is the sole general partner of KACALP. KAIM is owned by KA
        Holdings, Inc. ("KA Holdings"), a California corporation, the
        shareholders of which are Richard A. Kayne and John E. Anderson. The
        principal business address of the Reporting Persons, KAIM and KA
        Holdings is 1800 Avenue of the Stars, Second Floor, Los Angeles,
        California 90067.


b.      RICHARD A. KAYNE

        Mr. Kayne, a U.S. citizen, is President, Chief Executive Officer and
        Director of KAIM and KA Holdings.

        Mr. Kayne also serves as Co-Management Chair and Chief Executive Officer
        of Kayne Anderson Rudnick Investment Management, LLC, a California
        limited liability company ("KARIM"), and President and Director of KA
        Associates, Inc., a Nevada corporation ("KAA"). KARIM is a registered
        investment adviser. KAA is a registered broker/dealer. The principal
        business address of KARIM and KAA is 1800 Avenue of the Stars, Second
        Floor, Los Angeles, CA 90067.


c.      None of the Reporting Persons, KAIM or KA Holdings has been convicted in
        a criminal proceeding (excluding traffic violations or similar
        misdemeanors) in the past five years, nor has any of them been a party
        to a civil proceeding of a judicial or administrative body of competent
        jurisdiction, which resulted in a judgment, decree or final order
        enjoining future violations of, or prohibiting or mandating activities
        subject to, federal or state securities laws or finding any violation
        with respect to such law during the last five years.


5




d.      The following additional persons are officers and/or directors of one or
        more of KAIM and KA Holdings. (KACALP, a limited partnership, does not
        have any officers or directors.) Each such person is a U.S. citizen
        whose address is, unless noted otherwise, 1800 Avenue of the Stars,
        Second Floor, Los Angeles, California 90067. None of such persons has
        been convicted in a criminal proceeding (excluding traffic violations or
        similar misdemeanors) in the past five years, nor has any of them been a
        party to a civil proceeding of a judicial or administrative body of
        competent jurisdiction, which resulted in a judgment, decree or final
        order enjoining future violations of, or prohibiting or mandating
        activities subject to, federal or state securities laws or finding any
        violation with respect to such law during the last five years.

        JOHN E. ANDERSON.     Chairman of Topa Equities, Ltd., a diversified
                              investment company located at 1800 Avenue of the
                              Stars, Suite 1400, Los Angeles, California 90067.
                              Mr. Anderson is Director of KAIM and KA Holdings.

        HOWARD M. ZELIKOW.    Vice President and Director of KAIM

        ROBERT V. SINNOTT.    Vice President of KAIM

        RALPH C. WALTER.      Chief Operating Officer of KAIM and KA Holdings.

        DAVID J. SHLADOVSKY.  General Counsel and Secretary of KAIM and
                              KA Holdings.

        JOHN F. DALEY.        Chief Financial Officer and Treasurer of KAIM and
                              KA Holdings.


ITEM 3.  SOURCE AND AMOUNT OF FUNDS OR OTHER CONSIDERATION


ITEM 4.  PURPOSE OF TRANSACTION

This Amendment No. 15 is filed for purposes of disclosing that KACALP has
entered into a Voting Agreement, dated as of July 12, 2004 (the "Voting
Agreement"), by and among KACALP, Vulcan Capital ("Vulcan") and EnCap
Investments, L.L.C. ("EnCap"), pursuant to which, KACALP has granted Vulcan an
irrevocable proxy to direct the vote of its 1,662,650 shares as described below
in Item 6.


ITEM 5.  INTEREST IN SECURITIES OF THE ISSUER

Based upon information set forth in the definitive proxy statement filed by
Issuer with the Securities and Exchange Commission on June 23, 2004, as of June
14, 2004, there were 24,520,183 shares of the Issuer's Common Stock issued and
outstanding.

a. Mr. Kayne beneficially owns 1,743,266 shares of the Common Stock, or
approximately 7.1% of the outstanding Common Stock. Of those shares, KACALP, as
general partner of or investment adviser to investment funds or accounts,
beneficially owns 1,662,650 shares of the Common Stock, or approximately 6.8% of
the outstanding Common Stock.

b. (i) Mr. Kayne has the sole power to vote and dispose, or direct the
disposition, of 80,616 shares of the Common Stock, and (ii) Mr. Kayne and KACALP
have the shared power to vote and dispose, or direct the disposition, of
1,662,650 shares of the Common Stock.

The shares over which Mr. Kayne has sole voting and dispositive power are held
by him directly or by accounts for which he serves as trustee or custodian. The
shares over which Mr. Kayne and KACALP have shared voting and dispositive power
are held by accounts for which KACALP serves as general partner or investment
adviser.






6



KACALP disclaims beneficial ownership of the shares reported, except those
shares attributable to it by virtue of its general partner interests in the
limited partnerships holding such shares. Mr. Kayne disclaims beneficial
ownership of the shares reported, except those shares held by him or
attributable to him by virtue of his limited partner interests in such limited
partnerships and by virtue of his indirect interest in the interest of KACALP in
such limited partnerships.

c. The following transactions in the Common Stock beneficially owned by the
Reporting Persons were effected in the last 60 days:




                         Common Stock          Stock
  Date        Type        # of shares          Price      Where/how transaction effected
  ----        ----       ------------          -----      ------------------------------
                                             
5/21/04        sell            1,150           17.18      open market
5/21/04        sell              200           17.18      open market
5/26/04        sell              400           17.13      open market
5/26/04        sell              500           17.13      open market



d.  Not applicable

e.  Not applicable


ITEM 6. CONTRACTS, ARRANGEMENTS, UNDERSTANDINGS OR RELATIONSHIPS WITH RESPECT TO
SECURITIES OF THE ISSUER.

On February 19, 2004 (i) Vulcan, Mr. Paul G. Allen, Mr. James C. Flores and Mr.
John T. Raymond entered into an Amended and Restated Subscription Agreement,
dated as of February 19, 2004 (the "Subscription Agreement"), as amended on July
12, 2004, and (ii) the Issuer, Vulcan and Prime Time Acquisition Corporation, a
Delaware corporation ("Prime Time"), entered into an Agreement and Plan of
Merger, dated as of February 19, 2004 (the "Original Merger Agreement"), which
the parties amended by executing and delivering Amendment No. 1 to the Agreement
and Plan of Merger, dated as of July 12, 2004 (the "Amendment"). The Original
Merger Agreement, as amended by the Amendment, is referred to herein as the
"Merger Agreement"). In connection with the execution and delivery of the
Amendment by the Issuer, Vulcan and Prime Time, Vulcan, KACALP and EnCap entered
into the Voting Agreement.

KACALP entered into the Voting Agreement as a condition to the execution by
Vulcan of the Amendment, and beyond that, to KACALP's knowledge, no party
received consideration with the execution and delivery of the Voting Agreement.
Pursuant to the Voting Agreement, KACALP has a contractual obligation to vote
all of its respective shares of Common Stock (i) in favor of the approval and
adoption of the Merger Agreement and any actions required in furtherance
thereof, (ii) against any proposal to the stockholders of the Issuer that would
be reasonably likely to prevent the consummation of the proposed merger or to
result in the breach by the Issuer of the Merger Agreement, (iii) against (A)
any significant corporate transaction, such as a merger, consolidation, share
exchange, rights offering, reorganization, recapitalization, reclassification or
liquidation involving the Company or any of its subsidiaries, other than the
proposed merger, (B) any Acquisition Proposal (as defined in the Merger
Agreement, other than the proposed merger, or (C) any action that could
materially impede, interfere with, delay, postpone or adversely affect the
consummation of the proposed merger or the transactions contemplated by the
Voting Agreement, (iv) against any change in the composition of the Board of
Directors of the Issuer, other than as contemplated by the Merger Agreement, and
(v) against any amendment to the Second Restated Certificate of Incorporation or
Bylaws of the Issuer, as amended. KACALP has granted Vulcan an irrevocable proxy
under the Voting Agreement and is further restricted from transferring or
agreeing to transfer any of their shares of Common Stock or from granting any
proxy or power-of-attorney with respect to any shares of Common Stock
beneficially owned by it.

As a result of executing the Voting Agreement, KACALP may be deemed to have
formed a "group" with Vulcan and EnCap for purposes of Section 13(d) of the
Securities Exchange Act of 1934 and the rules promulgated thereunder, and such
"group" may be deemed to be the beneficial owner of the shares of Common Stock
beneficially owned by Vulcan and EnCap. KACALP expressly disclaims any assertion
or presumption that it and Vulcan and EnCap constitute a "group."




ITEM 7. MATERIAL TO BE FILED AS EXHIBITS.

Exhibit 1. Voting Agreement, dated as of July 12, 2--4, by and among Vulcan
Energy Corporation, Kayne Anderson Capital Advisors, L.P. and EnCap Investments,
L.L.C.



                                    SIGNATURE

    After reasonable inquiry and to the best of my knowledge and belief, I
certify that the information set forth in this statement is true, complete and
correct.


                 July 13, 2004
--------------------------------------------------
                     Date

             /S/ Richard A. Kayne
--------------------------------------------------
                Richard A. Kayne


KAYNE ANDERSON CAPITAL ADVISORS, L.P.

By:     Kayne Anderson Investment Management, Inc.


        By:  /S/ David J. Shladovsky
             -------------------------------------
             David J. Shladovsky, Secretary


               JOINT FILING AGREEMENT PURSUANT TO RULE 13d-1(f)(1)



This agreement is made pursuant to Rule 13d-1(f)(1) under the Securities
Exchange Act of 1934 (the "Act") by and between the parties listed below, each
referred to herein as a "Joint Filer." The Joint Filers agree that a statement
of beneficial ownership as required by Section 13(d) of the Act and the Rules
thereunder may be filed on each of their behalf on Schedule 13D or Schedule 13G,
as appropriate, and that said joint filing may thereafter be amended by further
joint filings. The Joint Filers state that they each satisfy the requirements
for making a joint filing under Rule 13d-1.



        ------------------------------------------------
        Richard A. Kayne



        ------------------------------------------------
        Kayne Anderson Capital Advisors, L.P., by
        David J. Shladovsky, Secretary of
        Kayne Anderson Investment Management, Inc.,
        general partner