REVOLVING CREDIT AGREEMENT

Exhibit 10.50

$5,000,000

REVOLVING CREDIT AGREEMENT

Between

Alliance Holdings GP, L.P.,

as Borrower

and

C-Holdings, LLC,

as Lender

Dated as of April __, 2006

TABLE OF CONTENTS

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REVOLVING CREDIT AGREEMENT

This REVOLVING CREDIT AGREEMENT, dated as of April __, 2006 (the “ Agreement ”), is between ALLIANCE HOLDINGS GP, L.P., a Delaware limited partnership (the “ Borrower ”), and C-HOLDINGS, LLC, a Delaware limited liability company (the “ Lender ”).

W I T N E S S E T H:

WHEREAS, the Borrower desires to obtain a revolving credit facility from the Lender in an amount of up to $5,000,000, and the Lender desires to make available to the Borrower such revolving credit facility, in each case upon the terms and conditions set forth herein;

NOW, THEREFORE, in consideration of the premises and the mutual covenants and agreements herein contained, the Borrower and the Lender hereby agree as follows:

ARTICLE I

DEFINITIONS AND ACCOUNTING TERMS; AMENDMENT AND RESTATEMENT

Section 1.1 Definitions . As used in this Agreement, and unless the context requires a different meaning, the following terms shall have the meanings indicated (such meanings to be, when appropriate, equally applicable to both the singular and plural forms of the terms defined):

“ Agreement ” has the meaning specified in the preamble hereof.

“ Bankruptcy Code ” shall mean Title 11 of the United States Code or any similar or successor federal law for the relief of debtors, as the same may be amended from time to time.

“ Borrower ” has the meaning specified in the preamble of this Agreement.

“ Borrowing Notice ” has the meaning specified in Section 2.2(a) hereof.

“ Business Day ” means any day on which commercial banks are open for business (and not required or authorized by law to close) in Tulsa, Oklahoma.

“ Commitment Fee ” has the meaning specified in Section 3.6 hereof.

“ Default Rate ” means the rate of interest applicable from time to time as specified under Section 3.3 hereof.

“ Dollars ”, “U.S.$” and the sign “$” mean such coin or currency of the United States of America as at the time shall constitute legal tender for the payment of public and private debts.

“ Event of Default ” has the meaning specified in Section 6.1 hereof.

“ Funding Date ” shall mean the date on which any loan shall be made by a Lender to the Borrower hereunder.

“ Indemnitee ” has the meaning specified in Section 7.7 hereof.

“ Interest Rate ” has the meaning specified in Section 3.1 hereof.

“ Lender ” has the meaning specified in the preamble of this Agreement.

“ LIBOR ” means, with respect to any calendar month while this Agreement remains in effect or any Obligations owing hereunder shall remain unpaid, the London interbank offered rate for Dollar deposits for a 30-day interest period as quoted on the first Business Day of such calendar month in the Wall Street Journal or, if not quoted therein on such date, as quoted in the Wall Street Journal on the immediately preceding Business Day; provided , however , that if LIBOR cannot be determined by reference to the Wall Street Journal , then LIBOR shall be determined by reference to another publicly available source or service (such as Bloomberg), as reasonably selected by the Lender, that displays LIBOR rates for comparable periods as of comparable dates. The LIBOR rate determined pursuant to this definition for any calendar month shall remain in effect for such calendar month from the first day of such calendar month to the last day of such calendar month.

“ Material Adverse Change ” shall mean any material adverse change in the business, operations, affairs, financial condition, assets or properties of the Borrower and any subsidiary thereof, taken as a whole.

“ Obligations ” shall mean all now existing or hereafter arising indebtedness, obligations, liabilities and covenants of the Borrower to the Lender arising under or in connection with or evidenced by this Agreement whether now or hereafter existing, or due or to become due, including, without limitation, all unpaid principal of and interest on, and all fees owing in respect of, the Revolving Loans.

“ Potential Event of Default ” means an event, condition or circumstance which, with the giving of notice or the lapse of time, or both, would constitute an Event of Default.

“ Revolving Loan(s) ” shall have the meaning specified in Section 2.1(a) hereof.

“ Revolving Loan Commitment ” shall mean the commitment of the Lender to make Revolving Loans in an aggregate amount of up to Five Million and no/100 Dollars ($5,000,000), as such amount may be reduced from time to time in accordance with the provisions of Section 2.1(c) hereof or pursuant to Section 6.1 hereof.

“ Termination Date ” shall mean the earlier of ( x ) March 31, 2007 and ( y ) the date that is 30 calendar days following the date on which the Lender shall have given written notice to the Borrower to the effect that, on (but not before) such 30th day (or such later

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date which shall be not more than 90 calendar days from the date of the giving of such notice), the Lender shall cease to be the legal and beneficial owner, directly or indirectly, of at least 50.1% of the outstanding equity voting interests of the sole or managing general partner of the Borrower.

Section 1.2 Time Period Computations . In the computation of a period of time specified in this Agreement from a specified date to a subsequent date, the word “from” means “from and including” and the words “to” and “until” mean “to but excluding”.

ARTICLE II

GENERAL PROVISIONS OF REVOLVING CREDIT FACILITY

Section 2.1 The Revolving Loans .

(a) Revolving Loan Borrowings . Subject to the terms and conditions of this Agreement, the Lender agrees to make revolving loans (each, a “ Revolving Loan ” and, collectively, the “ Revolving Loans ”) to the Borrower from time to time on and after the date hereof until one Business Day prior to the Termination Date in an aggregate principal amount outstanding at any time of up to, but not in excess of, the Revolving Loan Commitment. Within the limits and subject to the terms and conditions set forth in this Agreement, the Borrower may borrow up to the Revolving Loan Commitment pursuant to this Section 2.1 and Section 2.2 hereof, may prepay pursuant to Section 3.5 hereof, and reborrow under this Section 2.1 hereof.

(b) Recording of Loans . The Lender is hereby authorized to record in its books and records, among other things, the amount and Funding Date of each Revolving Loan made by the Lender and the amount and date of each payment or prepayment of any Revolving Loan. No failure to so record nor any error in so recording shall affect the obligations of the Borrower to repay the actual outstanding principal amount of the Revolving Loans, with interest thereon, as provided in this Agreement.

(c) Optional Termination or Reduction in Revolving Loan Commitment . The Borrower shall have the right, upon not less than 3 Business Days’ notice to the Lender, to terminate the unused part of the Revolving Loan Commitment; provided that no such termination or reduction shall be permitted to the extent that after giving effect thereto and to any prepayments of Revolving Loans made on the effective date thereof, the aggregate principal amount of the Revolving Loans then outstanding would exceed the Revolving Loan Commitment then in effect. Any such reduction shall be in an amount equal to $500,000 or a whole multiple of $100,000 in excess thereof, and shall reduce permanently the Revolving Loan Commitment then in effect.

Section 2.2 Revolving Loan Borrowing Procedures .

(a) Notice of Revolving Borrowing . Whenever the Borrower desires to borrow Revolving Loans under Section 2.1 hereof, the Borrower shall deliver to the Lender written notice (each such notice, a “ Borrowing Notice ”) no later than 5:00 p.m. (Central time) on the Business Day prior to the Funding Date of such Revolving Loan (or, in the sole discretion of the Lender, no later than 11:00 a.m. (Central time) on the Funding Date). The Borrowing Notice

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shall specify ( i ) that the Borrower wishes to effect one or more Revolving Loans, ( ii ) the aggregate principal amount of the Revolving Loan thereby requested (which shall not be less than $50,000.00 and shall be in multiples of $10,000, ( iii ) the requested Funding Date of such Revolving Loan, which date shall be a Business Day, and ( iv ) the total aggregate amount of the undrawn Revolving Loan Commitment then available. In lieu of delivering the above-described Borrowing Notice, the Borrower may give the Lender telephonic notice of any such proposed borrowing by the time period, as applicable, required under this Section 2.2(a); provided that such notice shall be confirmed in writing by delivery to the Lender promptly (but in no event later than 1:00 p.m. (Central time) on the Funding Date of the requested Revolving Loan) of a Borrowing Notice.

(b) Making of Revolving Loans . After receipt of a Borrowing Notice under clause (a) of this Section 2.2 (or telephonic notice, as the case may be), the Lender shall, subject to the provisions of Section 4.1 hereof, make the amount of the requested Revolving Loan available to the Borrower in Dollars and in immediately available funds not later than 3:00 P.M. (Central time) on the Funding Date applicable to the Revolving Loan specified in the Borrowing Notice.

ARTICLE III

INTEREST, FEES AND REPAYMENT

Section 3.1 Interest Rate on the Revolving Loans . The aggregate amount of all Revolving Loans outstanding from time to time shall bear interest at a rate per annum equal to LIBOR plus two (2.0%) (the “ Interest Rate ”).

Section 3.2 Interest after Due Date . In the event the Borrower fails to make any payment of the principal amount of or interest on any of the Revolving Loans or any other amount owing hereunder, in each case when due (whether by demand, acceleration or otherwise), the Borrower shall pay to the Lender interest on such unpaid amount, payable from time to time on demand, from the date such amount shall have become due to the date of payment thereof, accruing on a daily basis, at a per annum rate (the “ Default Rate ”) equal to the sum of ( x ) the Interest Rate plus ( y ) two percent (2%).

Section 3.3 Payment and Computations .

(a) Payments . All pay