Mont. Code Ann. § 50-37-110

Any person, firm, partnership, association, or corporation violating the provisions of this chapter shall be guilty of a misdemeanor and upon conviction shall be punished by a fine of not less than $100 or more than $500 or, in the case of individuals, the members of a partnership, and the responsible officers and agents of an association or corporation, by imprisonment in the county jail for a period of not less than 30 days or more than 6 months or by both such fine and imprisonment.