SECURED PROMISSORY NOTE
$767,893.99 April 23, 1998
For value received, SANTA BARBARA PARTNERS, an Oklahoma general partnership ("Borrower"),
HALLADOR PETROLEUM, LLP, a Colorado limited liability partnership, HALLADOR PETROLEUM
COMPANY, a Colorado corporation, HALLADOR PRODUCTION COMPANY, a Colorado corporation,
and TRIO PETROLEUM, INC., a California corporation (collectively, "Maker"), jointly and severally promise
to pay to the order of THE TCW COMMINGLED DEBT AND ROYALTY FUND IIIB, a California Limited
Partnership ("Holder"), the principal sum of Seven Hundred Sixty-Seven Thousand Eight Hundred Ninety-Three
and Ninety-Nine/Hundredths Dollars ($767,893.99) together with accrued interest from the date of disbursement
on the unpaid principal until paid in full at the rates and times as set forth herein. This Secured Promissory Note
(the "Note") is issued in connection with that certain Term Loan Agreement dated as of May 25, 1990 by and
among Borrower, Trust Company of the West, a California trust company, in the capacities set forth therein
("TCW"), and The TCW Commingled Debt and Royalty Fund IIIB, a California Limited Partnership (as
heretofore or hereafter amended, modified or supplemented, from time to time, the "Term Loan Agreement") and
replaces the Amended Secured Promissory Note dated as of May 25, 1990 executed by Borrower, as Maker,
in favor of Holder. As used herein, the term "Holder" shall mean Holder and any subsequent holder of this Note,
whichever is applicable from time to time. Capitalized terms used herein without definition shall have the meanings
set forth in the Term Loan Agreement.
2. Maturity Date.
(a) The unpaid principal balance hereof, together with all unpaid interest accrued thereon, and all other amounts
payable by Maker under the terms of the Loan Documents shall be due and payable on June 1, 1999 (the
"Maturity Date") unless sooner paid or as otherwise provided herein or in the Term Loan Agreement.
(b) If the Maturity Date should fall on a