S.D. Codified Laws § 10-26-5.1
If any of the following persons has annually, on or before September tenth, on a form prescribed by the Department of Revenue:
the county treasurer shall, in addition to the notice required by §§ 10-26-4 and 10-26-5, send the notice to take tax deed containing the information set forth in § 10-26-4 to the person in possession of the real property, the person in whose name the property is taxed, the mortgagee named in any unsatisfied mortgage then in force upon the real property, and, if the mortgage has been assigned, to the assignee of the mortgage, to any person holding a special assessment certificate which is a lien upon the real estate, and, in case bonds have been issued in lieu of assessment certificates, to the holder of the bond last maturing and also to the city auditor or town clerk of such municipal corporation, and to any other person who has or claims an interest in the real estate.
The county treasurer shall send the notice to take tax deed by certified mail to such person at the address as shown on the form. The notice shall contain the information set forth in § 10-26-4 and shall be mailed on or before November tenth.
SDCL 10-26-5.1