S.D. Codified Laws § 43-31-2
The homestead embraces the house used as a home by the owner of it, being either, real property or a mobile home, and if the owner has two or more houses or mobile homes thus used at different times and places, the owner shall select which he or she will retain as a homestead.
The homestead may not embrace more than one dwelling house or any other buildings except such as are properly appurtenant to the homestead. A shop, store, or other building situated on real property and really used or occupied by the owner in the prosecution of the owner's own ordinary business may be deemed appurtenant to the owner's homestead.
A mobile home may include any vehicle without motive power which can provide adequate, comfortable, all season quarters for the purpose of making it a residence and which vehicle is larger than two hundred forty square feet, measuring at the base of the vehicle. The mobile home must be registered in South Dakota at least six months prior to the claim of exemption.
SDCL 43-31-2