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, and 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, 1999, including without
limitation the power 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 substitutes, or any of
them, shall do or cause to be done by virtue hereof.


                                       
        /s/ Jean Gaulin                         /s/ Byron Allumbaugh
____________________________________      ____________________________________
            Jean Gaulin                             Byron Allumbaugh

       /s/ E. Glenn Biggs                    /s/ H. Frederick Christie
____________________________________      ____________________________________
           E. Glenn Biggs                        H. Frederick Christie

       /s/ W. E. Bradford                      /s/ Russell H. Herman
____________________________________      ____________________________________
           W. E. Bradford                          Russell H. Herman

        /s/ W. H. Clark                     /s/ Madeleine Saint-Jacques
____________________________________      ____________________________________
            W. H. Clark                         Madeleine Saint-Jacques

         /s/ Bob Marbut                        /s/ C. Barry Schaefer
____________________________________      ____________________________________
             Bob Marbut                            C. Barry Schaefer

    /s/ Katherine D. Ortega
____________________________________      ____________________________________
        Katherine D. Ortega                          H. Pete Smith


Dated: February 8, 2000