Mont. Code § 82-2-423
A person or corporation buying or treating ores from leased mines or mining claims shall furnish the lessor and the lessee of the mines or mining claims a true and correct copy of the statement of returns of ores from the sale or shipment. The statement shall show both the gross and net proceeds derived from the sale or shipment of ores. Upon shipment of the ores from leased premises, either for sale or treatment, the shipper shall furnish to any sampling works or smelter buying or treating them the names and post-office addresses of the lessor and the lessee interested in that shipment of ores, and within 7 days after receipt of the statement from the sampling works or smelter, the shipper shall make settlement with the lessor and the lessee for the shipment or sale of ores, based upon the statement received by the parties from the sampling works or smelter.
§ 82-2-423, MCA