S.D. Codified Laws § 10-25-3
The notice of intention to take a tax deed shall be served on the owner of record of the real property, the person in possession of the real property, the person in whose name the real property is taxed, and the mortgagee named in any unsatisfied mortgage in force on the real property of record in the office of the register of deeds of the county where the real property is located. However, if the mortgage has been assigned and the assignment is placed on record in the office of the register of deeds, then notice shall be served on the assignee in lieu of the mortgagee named in the mortgage. The notice of intention to take a tax deed shall also be served on any lienholder, any creditor of record, and other interested person as may appear from the records in the office of the register of deeds, the treasurer, or the clerk of courts. The treasurer may obtain any title information necessary to identify any person who appears from the records to have an interest in the real property as the owner, mortgagee, lienholder, or other interested person.
SDCL 10-25-3