CERTIFICATE
              ULTRAMAR DIAMOND SHAMROCK CORPORATION


     I, Harold D. Mallory, Assistant Secretary of ULTRAMAR DIAMOND SHAMROCK
CORPORATION, a Delaware corporation, and custodian of the books and records
of said corporation, do hereby certify that the following resolutions were
duly adopted by the Board of Directors of said corporation on April 23,
1997, and that said resolutions are in full force in effect.

     RESOLVED that the appropriate officers of the Corporation be, and
     hereby they are, authorized and directed on behalf of the Corporation
     to prepare, execute and file with the Securities and Exchange
     Commission a Registration Statement on Form S-8 for the registration
     under the Securities Act of 1933, as amended (the "1933 Act"), of the
     number of shares of Common Stock (the "Shares") of the Corporation
     available for issuance or transfer pursuant to each of the 401(k)
     Retirement Savings Plan and the Nonqualified 401(k) Plan, and to file 
     such amendments thereto as may, in the opinion of the officers
     executing the same on behalf of the Corporation, be necessary or
     proper to effect the registration of such Shares under the 1933 Act,
     and to cause to be filed with the Securities and Exchange Commission
     all such post-effective amendments, additional papers, prospectuses,
     undertakings and documents as may be necessary or advisable in order
     to make such registration statement effective, to comply with the
     provisions of the 1933 Act, and to comply with any undertakings of the
     Corporation made in connection with such registration.  

     RESOLVED that  Patrick J. Guarino, Curtis V. Anastasio, Harold D.
     Mallory, and Todd Walker, or any of them, be and hereby are
     designated to act on behalf of the Corporation as its agent or agents
     for service in respect of matters concerning the Registration
     Statements relating to the Shares with the powers enumerated in Rule
     487 of the Rules and Regulations of the Securities and Exchange
     Commission.  

     RESOLVED that the name of any officer or director of the Corporation
     signing the Registration Statements (and any amendments thereto) on
     its behalf may be signed pursuant to a power of attorney duly executed
     and delivered by the officer or director whose name is so signed.  

     RESOLVED that the proper officers and employees of the Corporation be,
     and hereby they are, authorized and directed in the name and on behalf
     of the Corporation to take any and all action which they in their
     discretion may deem necessary or advisable in order to register or
     qualify the Shares, or any number thereof, issued pursuant to such
     401(k) Retirement Savings Plan and such Nonqualified 401(k) Plan, for
     issuance and sale under the securities laws of any of the states of
     the United States of America, or to take any and all other action
     which they in their discretion may deem necessary or advisable in
     order to register or license the Corporation as a dealer or broker in
     securities in any such state or to secure permission for the
     Corporation to issue such Shares pursuant to such 401(k) Retirement
     Savings Plan and Nonqualified 401(k) Plan and in connection with such
     applications, registrations or qualifications to execute, acknowledge,
     verify, deliver, file and publish all such applications, reports,
     issuance, covenants, certified copies of resolution, powers of
     attorney, consents to service of process and any and all other papers
     or instruments as may be required under the laws of any such state,
     and to take any and all other action which they deem necessary or
     advisable in order to maintain such registration or qualification for
     as long as they deem to be in the best interest of the Corporation or
     in order to cancel such registration or qualification if and when they
     deem such cancellation to be in the best interest of the Corporation. 

     RESOLVED that if, in any state in which any application, statement,
     notice or other instrument is required for the purpose of registering
     or qualifying the Shares issued pursuant to the 401(k) Retirement
     Savings Plan and the Nonqualified 401(k) Plan for offering or sale or
     to register or license the Corporation as a dealer or broker in
     securities, a prescribed form of resolution or resolutions relating
     to such offering or sale or to any application, statement, notice or
     other instrument in connection is required, each such preamble and
     resolution shall be deemed to have been, and hereby is, adopted by
     this Board of Directors and the Secretary of the Corporation is hereby
     authorized and directed to certify any such preamble or resolution as
     though the same were now presented to this meeting, all such preambles
     and resolutions to be inserted in the Minute Book following the
     minutes of this meeting.  

     RESOLVED that the appropriate officers of the Corporation be, and
     hereby they are, authorized and directed to prepare, execute and file
     with the New York Stock Exchange listing applications, listing fee
     agreements and listing agreements with respect to the listing on such
     exchange, upon official notice of issuance of the Shares issued from
     time to time under and pursuant to the provisions of the 401(k)
     Retirement Savings Plan and the Nonqualified 401(k) Plan, and the
     proper officers of the Corporation be, and hereby they are, authorized
     and empowered to cause such listing applications to be amended and
     modified to the extent that the officers executing the same may deem
     necessary or proper and to cause to be filed with such exchange, all
     additional papers, undertakings, agreements and documents as may be
     necessary or advisable in order to cause such exchange to list those
     Shares.  

     RESOLVED that  Patrick J. Guarino, Curtis V. Anastasio, Harold D.
     Mallory, and Todd Walker, and any of them be, and hereby they are,
     authorized to appear if necessary or advisable before officials of
     such exchange, with authority to make changes in the listing
     applications relating to the Shares to be issued under and pursuant
     to the provisions of the 401(k) Retirement Savings Plan and the
     Nonqualified 401(k) Plan and take such steps as may be necessary to
     effect the listing of the Shares on such exchange.  

     RESOLVED that the Corporation's Transfer Agent be, and hereby it is
     duly authorized to either (a) issue or (b) transfer from the
     Corporation's treasury as may be authorized in the manner provided
     below, and that the Corporation's Registrar be and hereby it is duly
     authorized to register certificates of Common Stock of this
     Corporation issued or transferred from the Corporation's treasury
     pursuant to the terms of the 401(k) Retirement Savings Plan and the
     Nonqualified 401(k) Plan, upon written certification and authorization
     by the Chief Executive Officer, Chief Operating Officer and President,
     any Vice President, the Secretary, or Assistant Secretary of the
     Corporation that Shares were issued thereunder to each director or
     employee designated in such certification, that each such director or
     employee is entitled to receive the number of shares specified in such
     certification and that shares of Common Stock therefore are to be
     either issued or transferred from the Corporation's treasury, as the
     case may be. 

     RESOLVED that the appropriate officers and employees of the
     Corporation be, and hereby they are, authorized and directed to take
     any and all further action and do any and all other things that may
     be necessary, proper or advisable to effectuate the foregoing
     resolutions.

     RESOLVED that such further specific resolutions as may be required in
     connection with the  registration and listing of Shares as
     contemplated above be, and hereby they are, deemed adopted and such
     resolutions may be certified by the Secretary of the Corporation as
     having been adopted by the Board of Directors provided that a copy
     thereof is inserted in the Minute Book following the minutes of this
     meeting.


     IN WITNESS WHEREOF, I have set my hand and the seal of this
corporation upon this 22nd day of May, 1997.



                              /s/ HAROLD D. MALLORY
                                  Harold D. Mallory




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