SDCL § 11-2-26: Continuance of nonconforming uses permitted--Discontinuance.

Any lawful use, lot, or occupancy of land or premises existing at the time of the adoption of the zoning ordinance may be continued, even though the use, lot, or occupation does not conform to the provisions of the ordinance. However, if the nonconforming use, lot, or occupancy is discontinued for a period of more than one year, any subsequent use, lot, or occupancy of the land or premises shall conform with the zoning ordinance.