Idaho Code § 5-206.2

In every action for the recovery of real property, or the possession thereof, a person establishing a legal title to the property is presumed to have been possessed thereof within the time required by law, and the occupation of the property by another person is deemed to have been under and in subordination to the legal title, unless it appears that the property has been held and possessed adversely to such legal title, for twenty (20) years before the commencement of the action.