Mo. Rev. Stat. § 444.030
Any such person or persons who, by the permission or consent of the owner or lessee of any real estate, and having the right to mine thereon, and having entered and dug or mined thereon any lead ore or other mineral, shall have the right to the exclusive possession of such ore or mineral, except the royalty thereon, which shall be paid as herein provided, until he or they shall be paid or tendered by such owner or lessee of such real estate the then highest market price in cash paid by such owner or lessee for the same kind of ore or mineral dug or mined on said lands, and if no other such ores or minerals are at the time being dug or mined on said lands and sold to such owner or lessee, then the highest price paid for such ore or mineral dug on lands nearest thereto shall be paid or tendered by such owner or lessee in such case, and upon such payment or tender, the absolute right to the possession of such lead ore or other mineral so dug out and mined under the provisions of section 444.020, and for which such payment or tender shall have been made, shall vest in such owner or lessee.
§ 444.030, RSMo