S.D. Codified Laws § 21-42-1

In addition to and not in lieu of the method otherwise provided by the statutes of this state for the taking of tax deeds any purchaser of property at tax sale, or his assigns, including the county where property is bid in by the county treasurer for lack of bidders, desiring a tax deed for any such property or desiring to quiet the title to property already covered by tax deeds may bring an action in the circuit court for the county within which such real property is situated, which said action shall be brought as an action in equity, and except as herein provided, shall be prosecuted the same as in other civil actions.