Missouri Revised Statutes Title XVIII. Labor and Industrial Relations § 293.020. Applicability of law

Unless indicated otherwise, this chapter applies to all mines in this state engaged in the mining or extraction of minerals for commercial purposes, except barite, marble, limestone, and sand and gravel, or the prospecting for or the production of petroleum or natural gas; but does apply insofar as shale is mined or extracted for the purpose of recovering oil.