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                                                                       EXHIBIT 3




                      SECOND AMENDMENT TO RIGHTS AGREEMENT

                 This Second Agreement, dated as of April 26, 1996 (the
"Amendment"), is between MESA Inc., a Texas corporation (the "Company"), and
American Stock Transfer and Trust Company (the "Rights Agent"),

                              W I T N E S S E T H:

                 WHEREAS, the Company and the Rights Agent are parties to a
Rights Agreement dated as of July 6, 1995 and amended by a First Amendment
dated as of July 20, 1995 (as so amended, the "Agreement"); and

                 WHEREAS, pursuant to Section 27 of the Agreement, the Company
and the Rights Agent desire to amend the Agreement set forth below.

                 NOW, THEREFORE, in consideration of the premises and the
mutual agreements herein set forth, the parties hereby agree as follows:

                 Section 1.       Defined Terms.  Terms defined in the Rights
Agreement shall have the same meaning when used in this Amendment.

                 Section 2.       Amendments to Definitions.

                 (a)      The definition of "Acquiring Person" in Section 1 of
the Agreement is amended to add the following as a new fourth paragraph:

                          Notwithstanding anything contained in this Agreement
         to the contrary, neither DNR-MESA Holdings, L.P., a Texas limited
         partnership ("DNR"), nor any of its Affiliates or Associates shall
         become or be an Acquiring Person solely by virtue of either

                           (i)   the execution, delivery and performance of
                 either that certain Stock Purchase Agreement dated April 26,
                 1996 between DNR and the Company, as it may be amended from
                 time to time hereafter (such agreement, as so amended, being
                 herein called the "DNR Agreement") or of the Ancillary
                 Documents (as defined in the DNR Agreement); or

                           (ii)   the consummation of the Transaction (as 
                 defined in the DNR Agreement); or

                          (iii)  without limiting the generality of clauses
                 (i) and (ii) above, the beneficial ownership by any of such
                 Persons of shares of Common Stock as a result of their
                 beneficial ownership of shares of (A) Series B Preferred Stock
                 acquired by DNR pursuant to the DNR Agreement including,
                 without limitation, shares acquired at the "First Closing" or
                 the "Second Closing" (in





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                 each case as defined in the DNR Agreement); (B) Series A
                 Preferred Stock issued in exchange for Series B Preferred
                 Stock; and (C) Series A Preferred Stock and Series B Preferred
                 Stock issued as dividends;

         unless and until such time as any such Person, together with its
         Affiliates and Associates, is then the Beneficial Owner of 10% or more
         of the shares of Common Stock then outstanding (including, without
         limitation, by virtue of Beneficial Ownership referenced in clause
         (i), (ii) or (iii) above) and either (x) such Person shall then
         purchase or otherwise become the Beneficial Owner of any additional
         shares of Common Stock or (y) any other Person who is the Beneficial
         Owner of any shares of Common Stock shall become an Affiliate or
         Associate of DNR.

                 (b)      New definitions of  "Series A Preferred Stock" and
"Series B Preferred Stock" are hereby added to Section 1 of the Agreement as
follows:

                 "Series A Preferred Stock" shall mean the Series A 8%
                 Cumulative Convertible Preferred Stock, par value $.01 per
                 share, of the Company.

                 "Series B Preferred Stock" shall mean the Series B 8%
                 Cumulative Convertible Preferred Stock, par value $.01 per
                 share, of the Company.

                 Section 3.       Severability.  If any term, provision,
covenant or restriction of this Amendment is held by a court of competent
jurisdiction or other authority to be invalid, void or unenforceable, the
remainder of the terms, provisions, covenants and restrictions of this
Amendment shall remain in full force and effect and shall in no way be
affected, impaired or invalidated.

                 Section 4.       Governing Law.  This Amendment shall be
deemed to be a contract made under the laws of the State of Texas and for all
purposes shall be governed by and construed in accordance with the laws of such
State applicable to contracts made and to be performed entirely within such
State.

                 Section 5.       Counterparts.  This Amendment may be executed
in any number of counterparts and each of such counterparts shall for all
purposes be deemed to be an original, and all such counterparts shall together
constitute but one and the same instrument.

                 Section 6.       Effect of Amendment.  Except as expressly
modified herein, the Agreement shall remain in full force and effect.





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                          IN WITNESS WHEREOF, the parties hereto have caused
         this Amendment to be duly executed all as of the day and year first
         above written.

                                              MESA INC.


                                              By /s/ Stephen K. Gardner
                                                 ----------------------
                                                 Name: Stephen K. Gardner
                                                 Title: Vice President and 
                                                        Chief Financial Officer


                                              AMERICAN STOCK TRANSFER
                                               AND TRUST COMPANY


                                              By /s/ Herbert J. Lemmer 
                                                 ---------------------
                                                 Name: Herbert J. Lemmer 
                                                 Title: Vice President