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Exhibit 10.18

DS-459
9/26/95

STATE OF MONTANA

COAL LEASE

C-1100-00

        THIS LEASE, is made and entered into between the State of Montana, by and through its lawfully qualified and acting Board of Land Commissioners, hereinafter referred to as "Lessor", and

Spring Creek Coal Company
P.O. Box 57
Decker, MT 59025

hereinafter referred to as "Lessee", under and pursuant to the authority granted Lessor by the terms and provisions of Section 77-3-301 et seq ., MCA, all acts amendatory thereof and supplementary thereto, and all rules adopted pursuant thereto.

        IT IS MUTUALLY UNDERSTOOD, AGREED AND COVENANTED BY AND BETWEEN THE PARTIES TO THIS LEASE AS FOLLOWS:

        1.     GRANTING CLAUSE.     The Lessor, in consideration of the rents and royalties to be paid and the conditions to be observed as hereinafter set forth does hereby grant and lease to the lessee, for the purpose of mining and disposing of coal and constructing all such works, buildings, plants, structures and appliances as may be necessary and convenient to produce, save, care for, dispose of and remove said coal, and for the reclamation thereafter, all the lands herein described, as follows:

Land located in Big Horn County

Total Number of Acres: 150, more or less, belonging to School grant.

All rights granted to Lessee under this Lease are contingent upon Lessee's compliance with the Montana Strip Mine Siting Act and the Montana Strip and Underground Mine Reclamation Act (Title B2, Chapter 4, Parts 1 and 2, MCA). If these acts are repealed subsequent to the issuance of this Lease, all rights granted Lessee are contingent upon Lessor review and approval of Lessee's mine operation and reclamation plan. The rights granted under this Lease are further subject to agency responsibilities and authority under the provisions of the Montana Environmental Policy Act.

        2.     EFFECTIVE DATE AND TERM.     This lease takes effect on November 20, 2000 and is granted for a primary term of ten (10) years and so long thereafter as coal is produced from such lands in commercial quantities, subject to all of the terms and conditions herein set forth. A lease not producing coal in commercial quantities at the end of the primary term shall be terminated, unless the leased lands are described in a strip mine permit issued under Section 82-4-221, MCA, or in a mine site location permit under Section 82-4-122, MCA, prior to the end of the primary term, and the lease shall not be terminated so long as said lands are covered and described under valid permit.

        3.     RIGHTS RESERVED.     Lessor expressly reserves the right to sell, lease, or otherwise dispose of any interest or estate in the lands hereby leased, except the interest conveyed by this Lease; provided, however, that Lessor hereby agrees that subsequent sales, leases or other dispositions of any interest or estate in the lands hereby leased shall be subject to the terms of this Lease and shall not interfere with the Lessee's possession or rights hereunder.

        4.     BOND.     Lessee shall immediately upon the execution of this Lease furnish a surety bond in the amount of $1,000. conditioned upon compliance with the provisions of this Lease, or, in the option of the Lessor, a cash deposit in the amount of $1,000 or an irrevocable letter of credit in a form

approved by Lessor drawn upon an approved bank in the same amount. All rentals, royalties and interest must be paid and all disturbance must be reclaimed to the satisfaction of Lessor prior to release of any bond. Additional bonding may be required, or reduced bonding allowed, whenever Lessor determines it is necessary, or sufficient, to ensure compliance with this Lease.

        5.     RENTAL.     Lessee shall pay Lessor annually, in advance, for each acre or fraction thereof covered by this Lease, beginning with the date this Lease takes effect, an annual money rental of $3.00 per acre. Rental terms are subject to readjustment as provided in Paragraph 7, but in no case shall it be less than two (2) dollars per acre.

        6.     ROYALTY.     Lessee shall pay Lessor in money or in kind at Lessor's option a royalty on every short ton (2,000 pounds) of coal mined and produced during the term of this Lease, calculated upon the f.o.b. mine price of the coal prepared for shipment, including production-based taxes. Lessee shall pay a royalty of 12.5% upon coal removed by strip, surface, or auger mining methods and a royalty of 10.0% for coal removed by underground mining methods. Royalty terms are subject to review and readjustment as provided in Paragraph 7, but in no case shall the royalty for the coal mined be less than ten (10) percent of the f.o.b. price of a ton prepared for shipment.

        7.     READJUSTMENT OF RENTAL AND ROYALTY TERMS.     The rental and royalty terms of this Lease shall be subject to readjustment to reflect fair market value at the end of the primary term to ten (10 years) and at the end of each five (5) year period thereafter if the lease is producing coal in commercial quantities.

        8.     OFFSETTING PRODUCTION.     The obligation of Lessee to pay royalties under this Lease may be reduced by the Board for coal produced from any particular tract within the Lease upon a showing by Lessee to the Board that the coal is uneconomical to mine at prevailing market prices and operating costs unless Lesssor's royalty is reduced. Under no circumstances may Lessor's royalty be reduced below ten (10) percent of the coal produced and sold f.o.b. the mine site, prepared for shipment, including taxes based on production of value.

        9.     LESSOR NOTIFICATION AND REPORTS.     Lessee shall notify Lessor prior to the commencement of any prospecting, exploration, development or production operations. As soon as any mining operations are commenced, Lessee shall submit to Lessor, on or before the last day of each month, a royalty report and payment covering the preceding calendar month, which report shall be in such form and include such information as Lessor shall prescribe. Upon request, Lessee shall also furnish to Lessor, reports, plats, and maps showing exploration data, development work, improvements, amount of leased deposits mined, contracts for sale and any other information with respect to the land leased which Lessor may require. Lessor's point of contact for all matters related to this Lease is:

Department of Natural Resources & Conservation
Minerals Management Bureau
P. O. Box 201601
1625 Eleventh Avenue
Helena, MT 59620-1601

Lessor will notify Lessee of any subsequent change in point of contact.

        10.     INSPECTION.     Representatives of the Lessor shall at all times have the right to enter upon all parts of the leased premises for the purposes of inspection, examination, and testing that they may deem necessary to ascertain the condition of the Lease, the production of coal, and Lessee's compliance wi