Idaho Code § 5-207

When it appears that the occupant, or those under whom he claims, entered into the possession of the property under claim of title, exclusive of other right, founding such claim upon a written instrument, as being a conveyance of the property in question, or upon the decree or judgment of a competent court, and that there has been a continued occupation and possession of the property included in such instrument, decree or judgment, or of some part of the property under such claim, for twenty (20) years, the property so included is deemed to have been held adversely except that when it consists of a tract divided into lots, the possession of one (1) lot is not deemed a possession of any other lot of the same tract.