S.D. Codified Laws § 38-22-18

If the owner of infested land is not a resident of South Dakota, service of notice may be made by posting such notice at the courthouse in the county in which the land is situated, and by mailing to the last known address of the owner. Service is deemed complete five days after the date of the posting and mailing of the notices, which shall be evidenced by the affidavit of a person qualified to serve civil process in this state to be filed with the county auditor. However personal service upon the owner outside of this state is sufficient.