A certificate of purchase or of location of any lands in this state issued or made in pursuance of any law of the United States or of this state is prima facie evidence that the holder or assignee of the certificate is the owner of the land described in the certificate, but this evidence may be overcome by proof that at the time of the location or time of filing a preemption claim on which the certificate may have been issued, the land was in the adverse possession of the adverse party or those under whom the adverse party claims or that the adverse party is holding the land for mining purposes.
§ 70-19-305, MCA