SDCL § 15-3-7: Possession of real property presumed from legal title--Occupation by another presumed subordinate to legal title.

In every action for the recovery of real property or the possession thereof, the person establishing a legal title to the premises shall be presumed to have been possessed thereof within the time required by law; and the occupation of such premises by any other person shall be deemed to have been under and in subordination to the legal title, unless it appear that such premises have been held and possessed adversely to such legal title for twenty years before the commencement of such action.