Montana Title 15. Taxation § 15-37-103. Rate of tax

(1) The license tax to be paid by a person engaged in or carrying on the business of working or operating any mine or mining property in this state from which gold, silver, copper, lead, or any other metal or metals or precious or semiprecious gems or stones are produced is an amount computed on the gross value of product derived by the person from mining business, work, or operation within this state during the preceding reporting period.

(2) Concentrate shipped to a smelter, mill, or reduction work is taxed at the following rates:

(3) Gold, silver, or any platinum-group metal that is dore, bullion, matte, or another form of processed concentrate that is processed in a treatment facility owned or operated by the taxpayer and that is sold or shipped to a refinery for final processing is taxed at the following rates:

(4) The amount of gross value of product that is nontaxable under subsection (2) or (3) may not exceed $250,000 in a calendar year.