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                                                                 Exhibit 10.7(c)


THIS NOTE HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED,
OR APPLICABLE STATE SECURITIES LAWS, AND MAY NOT BE TRANSFERRED OR RESOLD EXCEPT
IN COMPLIANCE WITH SUCH LAWS. THE TRANSFER OF THIS NOTE IS ALSO SUBJECT TO
CERTAIN RESTRICTIONS SET FORTH IN THE PARTICIPATING SHAREHOLDER'S AGREEMENT,
DATED OCTOBER 30, 1992, BETWEEN THE COMPANY AND THE PAYEE.

                              INDIAN OIL COMPANY

                                UNSECURED NOTE

                                                         Date:  January 20, 1993
$352,226.42

     On or before January 20, 2003, INDIAN OIL COMPANY, an Oklahoma corporation
(the "Company"), for value received, hereby promises to pay to MICHAEL C. BLACK
the principal amount of Three Hundred Fifty-Two Thousand Two Hundred Twenty-Six
Dollars and Forty-Two Cents ($352,226.42), together with interest on the
principal amount from time to time remaining unpaid hereon at the rate of 10%
per annum from the date hereof until maturity, payable on the first day of each
March, June, September, and December of each year and at maturity. Both the
principal hereof and interest hereon are payable at the principal office of the
Company in coin or currency of the United States of America which at the time of
payment shall be legal tender for the payment of public and private debts. If
any amount of principal or interest on or in respect of this Note becomes due
and payable on any date which is not a Business Day, such amount shall be
payable on the next following Business Day. "Business Day" means any day other
than a Saturday, Sunday, statutory holiday or other day on which national banks
in the United States are required by law to close or are customarily closed.
Interest shall be computed on the actual number of days elapsed based on a year
consisting of 360 days.

     This Note is one of several Notes, all dated January 20, 1993, issued by
the Company in the aggregate principal amount of $2,000,000, and is issued under
and pursuant to the terms and provisions of those certain Participating
Shareholder's Agreements, all dated as of October 30, 1992, entered into by the
Company with the original purchasers of the Notes. All of the terms, conditions,
representations, warranties, covenants, and agreements contained in the
Participating Shareholder's Agreement are hereby incorporated by reference
herein.

     This Note and any other Notes outstanding under the Participating
Shareholder's Agreements may be declared due prior to their expressed maturity
dates, all in the events, on the terms and in the manner and amounts as provided
in the Participating Shareholder's Agreements. Any payment of principal and, to
the extent legally enforceable, interest which is not paid when due shall bear
interest at the rate of 18% per annum from the due date until paid.

     The Company may prepay the Notes in whole or in part at any time without
penalty, provided that prepayments shall be made on a pro rata basis on all
Notes and all unpaid accrued interest on the full unpaid principal balance of
the Note shall be paid with any prepayment.
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     This Note is subject to certain restrictions on transfer as set forth in
the Participating Shareholder's Agreements.

     Notwithstanding any agreement to the contrary, in no event, whether by
reason of acceleration of the maturity of this Note, prepayment of this Note in
whole or in part or otherwise, shall the amount paid or agreed to be paid for
the use, forbearance, or detention of the money loaned hereunder, or for the
payment or performance of any covenant or obligation contained in any other
document evidencing, securing or pertaining to this Note, exceed the maximum
amount permissible under applicable state law, if any, and federal law. If from
any circumstances whatsoever fulfillment of any provision hereof or of any of
such other documents, at the time performance of such provision shall be due,
shall involve transcending the limit of validity prescribed by law, then, ipso
                                                                          ----
facto, the obligation to be fulfilled shall be reduced to the limit of such
-----
validity, and if from any such circumstance there shall be paid interest or
anything of value deemed interest under applicable law which would exceed the
maximum rate allowed under law, such amount which would be excessive interest
shall be applied to the reduction of the principal amount owing on account of
this Note and not to the payment of interest, or if such excessive interest
exceeds the unpaid balance of principal of this Note, such excess shall be
refunded to the Company. All sums paid or agreed to be paid for the use,
forbearance or detention of the indebtedness of the Company shall, to the extent
permitted by applicable law, be amortized, prorated, allocated and spread
throughout the full term of such indebtedness until payment in full so the
actual rate of interest on account of such indebtedness complies with applicable
law throughout the term thereof. The terms and provisions of this paragraph
shall control and supersede every other provision of all agreements relating to
the indebtedness evidenced by this Note.

     This Note is governed by and construed in accordance with the laws of
Oklahoma.


                              INDIAN OIL COMPANY



                         By:  --------------------------------------
                              Richard R. Dunning, President