Mont. Code Ann. § 15-23-704

The tax on gross proceeds from coal must be levied as taxes on other forms of property, and this tax and the severance tax on coal production are each a lien upon the coal mine and a prior lien upon all personal property and improvements used to produce the coal. Unless suspended under the provisions of 15-23-708, taxes may be collected by the seizure and sale of the property used as collateral in consideration of a payment plan and personal property on which the tax is a lien as provided under 15-16-119 and 15-17-911.