(1) The lessee shall pay in cash a royalty on all coal produced from the leased premises at a rate of not less than ten percent of the value of the coal.

(2) The fair market value of the coal shall be determined by the board in accordance with 77-3-312 and 77-3-316(4), MCA.

(3) On or before the last day of each month, every holder of a producing coal lease shall make a report to the department on a form the department prescribes, showing the number of tons mined during the preceding calendar month, the price obtained therefore at the mine, the total amount of all sales, and any additional information required by the department. The report shall be signed by the lessee or some responsible person having knowledge of the facts reported and be accompanied by payment of the royalty due the state for the preceding month as shown by the report.

(4) The lessee shall report any adjustments to the sales price of the coal which affect the sales price as previously reported in the monthly reports within 30 days of the adjustment. The royalty shall be adjusted accordingly.