Mo. Rev. Stat. § 293.250

Every owner, agent or operator of any coal mine in this state, employing five or more persons, violating any of the provisions of sections 293.210 to 293.240, shall be deemed guilty of a misdemeanor, and on conviction shall be fined for each offense not less than fifty nor more than two hundred dollars, or by imprisonment in the county jail not less than three nor more than twelve months, or by both such fine and imprisonment.