SECURITIES AND EXCHANGE COMMISSION
   WASHINGTON, D.C.  20549

   SCHEDULE 14D-1
   AMENDMENT NO. 10
   TENDER OFFER STATEMENT PURSUANT TO SECTION 14(D)(1) OF THE SECURITIES
   EXCHANGE ACT OF 1934

   SANTA FE PACIFIC CORPORATION
   (NAME OF SUBJECT COMPANY)

   UNION PACIFIC CORPORATION
   UP ACQUISITION CORPORATION
   (BIDDERS)

   COMMON STOCK, PAR VALUE $1.00 PER SHARE

   (TITLE OF CLASS OF SECURITIES)

   802183 1 03
   (CUSIP NUMBER OF CLASS OF SECURITIES)

   RICHARD J. RESSLER
   ASSISTANT GENERAL COUNSEL
   UNION PACIFIC CORPORATION
   EIGHTH AND EATON AVENUES
   BETHLEHEM, PENNSYLVANIA  18018
   (610) 861-3200
   (NAME, ADDRESS AND TELEPHONE NUMBER OF PERSON AUTHORIZED TO
   RECEIVE NOTICES AND COMMUNICATIONS ON BEHALF OF BIDDERS)

   with a copy to:

   PAUL T. SCHNELL, ESQ.
   SKADDEN, ARPS, SLATE, MEAGHER & FLOM
   919 THIRD AVENUE
   NEW YORK, NEW YORK  10022
   TELEPHONE:  (212) 735-3000
                                                                         
          Union Pacific Corporation, a Utah corporation ("Parent"),
     and UP Acquisition Corporation, a wholly owned subsidiary of
     Parent (the "Purchaser"), hereby amend and supplement their
     Statement on Schedule 14D-1 ("Schedule 14D-1"), filed with the
     Securities and Exchange Commission (the "Commission") on November
     9, 1994, as amended by Amendment No. 1, dated November 10, 1994,
     Amendment No. 2, dated November 14, 1994,  Amendment No. 3, dated
     November 18, 1994, Amendment No. 4, dated November 22, 1994,
     Amendment No. 5, dated November 23, 1994,  Amendment No. 6, dated
     November 29, 1994, Amendment No. 7, dated December 2, 1994,
     Amendment No. 8, dated December 8, 1994, and Amendment No. 9,
     dated December 15, 1994, with respect to the Purchaser's offer to
     purchase 115,903,127 shares of Common Stock, par value $1.00 per
     share (the "Shares"), of Santa Fe Pacific Corporation, a Delaware
     corporation (the "Company").

          Unless otherwise indicated herein, each capitalized term
     used but not defined herein shall have the meaning assigned to
     such term in Schedule 14D-1 or in the Offer to Purchase referred
     to therein.

     ITEM 3.  PAST CONTACTS, TRANSACTIONS OR NEGOTIATIONS WITH 
              THE SUBJECT COMPANY.

          The information set forth in Item 3(b) of Schedule 14D-1 is
     hereby amended and supplemented by the following information:

          On December 14, 1994, Drew Lewis, Chairman and Chief
     Executive Officer of Parent, sent a letter, dated December 14,
     1994, to the Company; a copy of the letter is attached hereto as
     Exhibit (g)(9) and incorporated herein by reference.

          On December 16, 1994, Parent issued a press release
     announcing that Parent continues to be willing to consider and
     discuss revisions to its proposals to acquire the Company.  The
     press release also announced that Parent's legal counsel sent a
     letter, dated December 15, 1994, to the Company's legal counsel
     and that Drew Lewis, sent a letter, dated December 16, 1994, to
     the Company.  A copy of the press release, the letter to the
     Company, and the letter to the Company's legal counsel are
     attached hereto as Exhibit (a)(23) and incorporated herein by
     reference.


     ITEM 10.  ADDITIONAL INFORMATION.

          The information set forth in Item 10(f) of Schedule 14D-1 is
     hereby amended and supplemented by the following information:

          On December 16, 1994, Parent issued a separate press release
     announcing that it has extended the Expiration Date of the Offer
     to 12:00 midnight, New York City time, on Thursday, January 19,
     1995.  Parent also announced that as of 12:00 midnight, New York
     City time, on Thursday, December 15, 1994, approximately
     28,700,000 Shares had been tendered in the Offer.  A copy of the
     press release is attached hereto as Exhibit (a)(24) and
     incorporated herein by reference. 

     ITEM 11.  MATERIAL TO BE FILED AS EXHIBITS.

          (a)(23)   Text of Press Release issued by Union Pacific
                    Corporation on December 16, 1994.

          (a)(24)   Text of Press Release issued by Union Pacific
                    Corporation on December 16, 1994.

          (g)(9)    Letter, dated December 14, 1994, by Union
                    Pacific Corporation to Santa Fe Pacific Corporation.


                                 SIGNATURE

          After due 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.

     Dated:  December 16, 1994

                                     UNION PACIFIC CORPORATION

                                     By: /s/ Gary M. Stuart           
                                        _________________________
                                        Title: Vice President and
                                                 Treasurer


                                 SIGNATURE

          After due 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.

     Dated:  December 16, 1994

                                     UP ACQUISITION CORPORATION

                                     By: /s/ Gary M. Stuart           
                                        _____________________________
                                        Title: Vice President and
                                                 Treasurer
          


                               EXHIBIT INDEX

     Exhibit No.         Description

          (a)(23)   Text of Press Release issued by Union Pacific
                    Corporation on December 16, 1994.

          (a)(24)   Text of Press Release issued by Union Pacific
                    Corporation on December 16, 1994.

          (g)(9)    Letter, dated December 14, 1994, by Union
                    Pacific Corporation to Santa Fe Pacific Corporation.



                                                    Exhibit (a)(23)

          (UNION PACIFIC                     NEWS RELEASE
          CORPORATION - LOGO)

                                             Contact:  610-861-3388
                                             Harvey S. Turner
                                             Director - Public Relations
                                             Martin Tower
                                             Eighth and Eaton Avenues
                                             Bethlehem, PA  18018

                                             FOR IMMEDIATE RELEASE

          UNION PACIFIC ADVISES SANTA FE IT WILL CONSIDER REVISIONS 
            TO ITS PROPOSAL IF SANTA FE ESTABLISHES FAIR PROCESS   

          BETHLEHEM, PA, DECEMBER 16, 1994 -- Union Pacific
          Corporation (NYSE:UNP) said it continues to be willing to
          consider and discuss revisions to its proposal to acquire
          Santa Fe Pacific Corporation (NYSE:SFX), provided that
          Santa Fe establishes a fair process to consider competing
          acquisition proposals.

               Responding to a letter from Santa Fe's Chairman and
          CEO, Robert Krebs, Drew Lewis, Union Pacific's Chairman
          and CEO, said "Your characterization of Santa Fe's
          process for considering bids, or lack of such a process,
          is inaccurate and distorted . . .  Santa Fe has pursued a
          process that favors any outcome other than a transaction
          with Union Pacific.  We are extremely disappointed with
          the flawed and biased sale process being pursued by Santa
          Fe."

               Lewis added, "Let me be very clear.  By your actions
          you have put Santa Fe up for sale and Union Pacific is a
          very interested buyer.  We want to acquire Santa Fe by
          competing on an equal basis with Burlington Northern and
          any other potential bidders.  If Santa Fe establishes a
          fair and open process, we would be eager to participate,
          and would be willing to consider and discuss revisions to
          our proposal."

               In his letter to Krebs, Lewis described the numerous
          deficiencies in Santa Fe's sale process, including Santa
          Fe's refusal to even consider a proposal from Union
          Pacific valued at less than $20 per Santa Fe share.  Mr.
          Lewis said, "Your insistence on such a high minimum price
          as a condition to a transaction with Union Pacific
          discourages any transaction with Union Pacific while you
          pursue a variety of alternative transactions with
          Burlington Northern at a lower value level."

               Mr. Lewis also criticized Santa Fe for using Union
          Pacific as a stalking horse for an improved Burlington
          Northern bid.  Mr. Lewis said, "You have simply sought
          'clarifications' from us while repeatedly asking us to
          'improve' what for many weeks has been the most
          attractive proposal on the table . . .  We must assume
          that Santa Fe is using information obtained in its
          discussions with Union Pacific to assist Burlington
          Northern in its efforts to improve its bid."

               The text of Lewis' letter to Krebs and the letter to
          Santa Fe's counsel are attached.



                                        December 16, 1994

          Mr. Robert D. Krebs
          Chairman, President and CEO
          Santa Fe Pacific Corporation
          1700 East Golf Road
          Schaumburg, IL  60173

          Dear Rob:

                    I have read your December 15 letter, and can
          only conclude that you have not been kept fully apprised
          of the actions of your management and advisors.

                    Your characterization of Santa Fe's process for
          considering bids, or lack of such a process, is
          inaccurate and distorted.  Most importantly, you have
          not, as you assert, done everything you can to enable
          Union Pacific to revise its proposal.  On the contrary,
          Santa Fe has pursued a process that favors any outcome
          other than a transaction with Union Pacific.  

                    We are extremely disappointed with the flawed
          and biased sale process being pursued by Santa Fe.  Our
          financial advisor, CS First Boston, expressed our
          concerns to your financial advisor, Goldman Sachs, on
          December 14.  On December 15, before you sent me your
          letter, our counsel expressed these concerns in a letter
          to your counsel, a copy of which is enclosed.

                    And now, in light of your letter, I will tell
          you directly of our concerns.

                    Here are the facts:

                    1.   Your advisors have said you will not even
          consider a proposal from us at less than $20 per share,
          although you negotiated and recommended several
          transactions with Burlington Northern at prices well
          below $20 per share.  Your insistence on such a high
          minimum price as a condition to a transaction with Union
          Pacific discourages any transaction with Union Pacific
          while you pursue a variety of alternative transactions
          with Burlington Northern at a lower value level.

                    2.   Santa Fe has refused to establish any
          procedures that would permit us to compete on an equal
          basis with Burlington Northern.  While you obviously have
          continued to engage in serious, substantive negotiations
          with Burlington Northern, you have simply sought
          "clarifications" from us while repeatedly asking us to
          "improve" what for many weeks has been the most
          attractive proposal on the table.  You are using Union
          Pacific as a stalking horse for an improved Burlington
          Northern bid.  Based on your agreement with Burlington
          Northern, we must assume that Santa Fe is using
          information obtained in its discussions with Union
          Pacific to assist Burlington Northern in its efforts to
          improve its bid.

                    3.   Santa Fe has discussed alternative
          acquisition structures with Burlington Northern, but,
          despite our stated willingness to consider alternative
          structures and revisions to our current proposal, you
          have not given us any indication of what alternative
          structures would be acceptable to Santa Fe.

                    4.   Santa Fe, in its recent Schedule 14D-9
          filing, stated that our proposal "is subject to a number
          of conditions that are of concern to [Santa Fe]."  But,
          the fact is, Union Pacific's proposal contains fewer
          conditions, and provides greater certainty for your
          shareholders, than the transaction you willingly agreed
          to with Burlington Northern.

                    5.   Santa Fe's Board of Directors unilaterally
          adopted a "poison pill" rights plan that specifically
          exempts Burlington Northern but is applicable to our
          proposal.

                    6.   Santa Fe has stood silently by while
          Burlington Northern, your preferred suitor, has tried
          unsuccessfully to block ICC approval of our voting trust. 
          This is the voting trust that you specifically asked us
          to establish more than two months ago and that provides
          speed and certainty for your shareholders.

                    7.   Santa Fe apparently never asked its
          financial advisor to express its opinion as to the
          fairness of our proposal, but, as you know, Santa Fe
          previously  requested and received a fairness opinion on
          the Burlington Northern merger which, at the time, based
          on the then current market price, valued Santa Fe shares
          at approximately $13.50.

                    This listing is by no means exhaustive but is
          illustrative of the flawed and biased sale process
          undertaken by Santa Fe.  In light of this, the assertion
          that Santa Fe's goal has been to achieve the best results
          for its shareholders rings hollow.

                    Let me be very clear.  By your actions you have
          put Santa Fe up for sale and Union Pacific is a very
          interested buyer.  We want to acquire Santa Fe by
          competing on an equal basis with Burlington Northern and
          any other potential bidders.  If Santa Fe establishes a
          fair and open process, we would be eager to participate,
          and would be willing to consider and discuss revisions to
          our proposal.

                    Santa Fe has stated that it is considering
          alternative structures.  If you and your Board truly
          desire a fair process, it is incumbent upon you to inform
          us promptly of each alternative under consideration, to
          state the minimum bidding level (if any) applicable to
          all interested parties, and to give us the opportunity to
          consider and respond to each alternative.  In addition,
          you should instruct your management and advisors to
          establish immediately a fair and unbiased sale process. 
          If you would like our specific suggestions concerning
          establishing a fair process, our advisors would be
          pleased to provide them.


                    Santa Fe has not necessarily received Union
          Pacific's best proposal.  I await your response.

                                        Sincerely,

                                        /s/ Drew

                                                                   


          [Skadden, Arps Letterhead]

                                        December 15, 1994

          BY FACSIMILE

          Scott J. Davis, Esq.
          Mayer, Brown & Platt
          190 South LaSalle Street
          Chicago, Illinois  60606

          Dear Scott:

                    On behalf of Union Pacific, I am writing to
          raise a number of concerns with the process that Santa Fe
          has established for considering competing proposals to
          acquire Santa Fe.  These issues were described yesterday
          in detail by CS First Boston to Goldman Sachs and also
          were referred to in a letter from Drew Lewis to Robert
          Krebs.

                    As CS First Boston advised Goldman Sachs
          yesterday, Santa Fe has not necessarily received Union
          Pacific's best proposal.  Union Pacific has been and is
          willing to consider and discuss revisions to its
          proposal.  However, Union Pacific's response at this
          stage is a function of Santa Fe's having pursued what we
          believe is a flawed sale process.  Santa Fe has failed to
          treat bidders on a fair and equal basis and appears to be
          pursuing a process that favors any outcome other than a
          transaction with Union Pacific.

                    Specifically, among other things, Santa Fe's
          financial advisors have repeatedly stated that Santa Fe
          will not negotiate a transaction with Union Pacific
          unless Union Pacific confirms that it is prepared to
          provide value of at least $20 per Santa Fe share.  This
          position is inconsistent with Santa Fe's negotiating and
          recommending several transactions with Burlington
          Northern, all of which have been at prices well below
          $20.  We are concerned that your insistence on such a
          high price as a condition to a transaction with Union
          Pacific serves to discourage any transaction with Union
          Pacific while you pursue a variety of alternative
          transactions with Burlington Northern at a lower value
          level.  If you also have told Burlington Northern and any 
          other interested parties that you will not negotiate a 
          transaction unless it provides value of at least $20 per 
          share, you should disclose to us and the public that you 
          have established a $20 bidding floor for all potential 
          purchasers.

                    We are further concerned that Santa Fe has
          limited itself to "clarifying" Union Pacific's proposal,
          while apparently engaging in extensive substantive
          negotiations with Burlington Northern.  Santa Fe's
          process appears designed to use Union Pacific as a
          stalking horse, and use what we discuss with you in your
          negotiations with Burlington Northern.

                    There have been reports about Santa Fe's
          consideration of alternative structures for a
          transaction.  We are prepared to consider alternative
          structures and request that you promptly advise us of any
          alternatives which your client may prefer.

                    Please advise Santa Fe that Union Pacific is
          eager to participate in a fair process, and is willing to
          consider and negotiate revisions to its proposal.  Union
          Pacific asks only that it be treated on an equal basis
          with Burlington Northern.

                    You will be receiving today by separate cover a
          revised form of merger agreement.  Union Pacific's draft
          merger agreement contains fewer conditions, and provides
          greater certainty, than your agreement with Burlington
          Northern.  Notwithstanding this, Union Pacific is
          prepared to discuss any and all remaining concerns you
          may have.  

                    We note that our agreement does not contain any 
          "lock-up" provision, despite Union Pacific's having
          unilaterally offered Santa Fe a right to terminate any
          agreement with Union Pacific in order to accept a
          superior proposal--a right which does not exist in your
          current agreement with Burlington Northern.  We expect
          that your concerns about providing Union Pacific with any
          lock-up or expense reimbursement apply equally to
          Burlington Northern and that you will not provide
          Burlington Northern any stock or asset rights, a "bust
          up" fee or other arrangement that would in any manner
          impede Union Pacific's efforts to pursue a transaction
          with Santa Fe.

                    I would appreciate your discussing these
          matters with your client and responding to us at your
          earliest convenience.

                                        Sincerely,

                                        Paul T. Schnell  

          cc:  Carl W. von Bernuth, Esq.



                                                         Exhibit (a)(24)




               (UNION PACIFIC                     NEWS RELEASE
               CORPORATION - LOGO)

                                                  Contact:  610-861-3388
                                                  Harvey S. Turner
                                                  Director - Public Relations
                                                  Martin Tower
                                                  Eighth and Eaton Avenues
                                                  Bethlehem, PA  18018

                                                  FOR IMMEDIATE RELEASE


                      UNION PACIFIC EXTENDS SANTA FE PACIFIC OFFER


               BETHLEHEM, PA, DECEMBER 16, 1994 -- Union Pacific
               Corporation (NYSE: UNP) said today that it has extended
               the expiration date of its tender offer for 115,903,127
               shares of the Common Stock of Santa Fe Pacific
               Corporation (NYSE: SFX) to 12:00 midnight, New York City
               time, on Thursday, January 19, 1995.  As of 12:00
               midnight, New York City time, on Thursday, December 15,
               1994, approximately 28,700,000 shares of Santa Fe Common
               Stock had been tendered in the offer.



                                               Exhibit (g)(9)

     [Letterhead of 
     Union Pacific Corporation]

                                   December 14, 1994

     Mr. Robert D. Krebs
     Chairman, President and CEO
     Santa Fe Pacific Corporation
     1700 East Golf Road
     Schaumburg, IL  60173

     Dear Rob:

               I am writing to advise you, as requested by
     your advisors, of our position concerning our merger
     proposal.

               Our response at this stage is a function of
     Santa Fe's having pursued a flawed sale process.  Your
     advisors have repeatedly demanded that we improve our
     proposal while refusing to establish any procedures for
     considering competing proposals on a fair and equal
     basis.  In fact, your advisors have frequently told us
     you will not negotiate with Union Pacific unless we agree
     to pay at least $20 per Santa Fe share.  This position is
     clearly inconsistent with your negotiating and
     recommending several transactions with Burlington
     Northern at prices well below $20.

               We believe our current proposal is an extremely
     attractive one and in the best interests of Santa Fe and
     its shareholders and customers.  Despite this, you have
     continued to pursue a process that favors any result
     other than a transaction with Union Pacific.  We are
     prepared to continue discussions with you, but we urge
     you to establish a fair and open sale process.

                                   Sincerely,

                                   /s/ Drew