SIXTH AMENDMENT OF REVOLVING CREDIT AND TERM LOAN AGREEMENT


          THIS SIXTH AMENDMENT OF REVOLVING CREDIT AND TERM LOAN AGREEMENT (this
"Amendment"), dated as of February 13, 1998, is by and among TIPPERARY
CORPORATION, a Texas corporation ("Tipperary"), TIPPERARY OIL & GAS CORPORATION,
a Texas corporation ("TOG"), and U.S. BANK NATIONAL ASSOCIATION, a national
banking association ("USB"), f/k/a COLORADO NATIONAL BANK, a national banking
association ("CNB").

                                      RECITALS
                                          
          A.   Tipperary, TOG and CNB are parties to a Revolving Credit and Term
Loan Agreement dated as of March 30, 1992, as amended (as so amended, the "Loan
Agreement"), setting forth the terms upon which CNB would make loans to
Tipperary and TOG and by which such loans would be governed.  Capitalized terms
used herein but not defined herein shall have the same meanings as set forth in
the Loan Agreement.

          B.   USB is the successor to CNB.

          C.   Tipperary, TOG and USB wish to enter into this Amendment in order
to amend further certain terms and provisions of the Loan Agreement.

                                     AGREEMENT

          NOW, THEREFORE, in consideration of $10.00 and other good and valuable
consideration, the receipt and sufficiency of which are hereby acknowledged, the
parties hereby agree as follows:

          1.   LOAN AGREEMENT.  The Loan Agreement shall be, and hereby is,
amended, effective as of the date hereof:

               (a)  All references in the Loan Agreement to "Colorado National
Bank" shall be changed to be references to "U.S. Bank National Association."

               (b)  The Borrowing Base under the Loan Agreement for the time
period commencing February 13, 1998 and ending August 31, 1998 shall be
increased to $16,500,000.  The semi-annual Borrowing Base redetermination
scheduled for July 31, 1998 under Section 2.14 of the Loan Agreement shall be
re-scheduled to August 31, 1998.  To the extent that the outstanding principal
balance of the Loan exceeds $12,000,000 at any time, Borrowers shall designate
not more than two LIBO rate tranches (and from and after March 27, 1998, one
LIBO Rate tranche) having an aggregate principal amount of exactly $12,000,000
as the "Low-Interest Portion" of the Loan.

               (i)  In line 19 of Section 2.9 on page 15 of the Loan Agreement,
the "Maturity Date" shall remain unchanged at September 5, 2002.  The reference
in Clause 2) of Section 2.9 on

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page 15 of the Loan Agreement to the Term Loan amortizing in "48 equal monthly
principal payments" shall be changed to "36 equal monthly principal payments."

          2.   LOAN DOCUMENTS.  All references in any document to the Loan
Agreement shall refer to the Loan Agreement, as amended pursuant to this
Amendment.

          3.   CONDITIONS PRECEDENT.  The obligations of the parties under this
Amendment are subject, at the option of USB, to the prior satisfaction of the
condition that Tipperary and TOG shall have delivered to USB the following (all
documents to be satisfactory in form and substance to USB and, if appropriate,
duly executed and/or acknowledged on behalf of the parties other than USB):

               (a)  This amendment.

               (b)  An Amendment of Subordination Agreement and Consent of
     Subordinating Party in the form of Exhibit A attached hereto and made a
     part hereof.

               (c)  any and all other loan documents required by USB, including
     without limitation such amendments and supplements to the Collateral
     Documents as may be required by USB.

               (d)  A loan fee in the amount of $10,000.

          4.   REPRESENTATIONS AND WARRANTIES.  Tipperary and TOG hereby certify
to USB that as of the date of this Amendment all of Tipperary's and TOG's
representations and warranties contained in the Loan Agreement are true,
accurate and complete in all material respects, no Event of Default has
occurred under the Loan Agreement, and no event has occurred that with the
passage of time or notice, or both, would constitute an Event of Default under
the Loan Agreement.

          5.   CONTINUATION OF THE LOAN AGREEMENT.  Except as specified in this
Amendment, the provisions of the Loan Agreement shall remain in full force and
effect, and if there is a conflict between the terms of this Amendment and those
of the Loan Agreement, the terms of this Amendment shall control.

          6.   EXPENSES.  Tipperary and TOG shall pay all reasonable expenses
incurred in connection with the transactions contemplated by this Amendment,
including without limitation all reasonable fees and expenses of USB's attorney
and any and all recording and filing fees, charges and expenses.

          7.   MISCELLANEOUS.  This Amendment shall be governed by and construed
under the laws of the State of Colorado and shall be binding upon and inure to
the benefit of the parties hereto and their successors and assigns.  This
Amendment may be executed in any number of counterparts, each of which shall be
an original, but all of which together shall constitute one instrument.

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          Executed as of the date first above written.

                              TIPPERARY CORPORATION


                              By:  /s/ David L. Bradshaw
                                   --------------------------------------------
                                   David L. Bradshaw,
                                   President

                              TIPPERARY OIL & GAS CORPORATION


                              By:  /s/ David L. Bradshaw
                                   --------------------------------------------
                                   David L. Bradshaw,
                                   President

                              U.S. BANK NATIONAL ASSOCIATION
                                   f/k/a/ COLORADO NATIONAL BANK


                              By:  /s/ Charles S. Searle
                                   --------------------------------------------
                                   Charles S. Searle,
                                   Senior Vice President