EXHIBIT 24.1

                                POWER OF ATTORNEY

     The  undersigned  directors  and/or officers of Ultramar  Diamond  Shamrock
Corporation,  hereby constitute and appoint Timothy J. Fretthold, H. Pete Smith,
Curtis  V.  Anastasio,  Todd  Walker,  or any of them,  their  true  and  lawful
attorneys-in-fact   and  agents,  each  with  full  power  of  substitution  and
resubstitution,  to do any and all acts and  things in their  name and behalf in
their  capacity  as a director  and/or  officer  of  Ultramar  Diamond  Shamrock
Corporation and to execute any and all instruments for them and in their name in
such capacity, which said attorneys-in-fact and agents, or any of them, may deem
necessary or advisable to enable Ultramar Diamond Shamrock Corporation to comply
with the Securities Exchange Act of 1934, as amended, and any rules, regulations
and requirements of the Securities and Exchange  Commission,  in connection with
the Annual Report on Form 10-K of Ultramar Diamond Shamrock  Corporation for the
fiscal year ended December 31, 1997,  including  without  limitation,  power and
authority to sign for them, in their name in the capacity  indicated above, such
Form 10-K and any and all  amendments  thereto,  and to file the same,  with all
exhibits  thereto,  and  other  documents  in  connection  therewith,  with  the
Securities and Exchange Commission, hereby ratifying and confirming all that the
said  attorneys-in-fact  and agents, or their substitute or substitutes,  or any
one of them, shall do or cause to be done by virtue hereof.


/s/ R. R. HEMMINGHAUS                       /s/ JEAN GAULIN
    R. R. HEMMINGHAUS                           JEAN GAULIN


/s/ E. GLENN BIGGS                         /s/ BYRON ALLUMBAUGH
    E. GLENN BIGGS                             BYRON ALLUMBAUGH

/s/ W. E. BRADFORD                         /s/ H. FREDERICK CHRISTIE
    W. E. BRADFORD                             H. FREDERICK CHRISTIE

/s/ W. H. CLARK                            /s/ RUSSELL H. HERMAN
    W. H. CLARK                                RUSSELL H. HERMAN

/s/ BOB MARBUT                             /s/ MADELEINE SAINT-JACQUES
    BOB MARBUT                                 MADELEINE SAINT-JACQUES

/s/ KATHERINE D. ORTEGA                    /s/ C. BARRY SCHAEFER
    KATHERINE D. ORTEGA                        C. BARRY SCHAEFER

                                           /s/ H. PETE SMITH
                                               H. PETE SMITH

Dated: February 4, 1998

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