S.D. Codified Laws § 21-35-10
If there are unknown owners or persons interested in the property to be taken or damaged, or if any of the defendants are not residents of the state, the plaintiff may apply to the court upon affidavit setting forth the nature of the proceeding, and the facts in relation to such unknown persons or nonresident defendants, for an order of publication of such summons, whereupon the court shall grant such order. The summons as published shall have annexed thereto a notice that if the defendants as to whom publication has been ordered do not appear in said proceeding within thirty days from the first publication thereof, the plaintiff will make application to the court for the order mentioned in the body of the summons. Such summons shall be published for thirty days at least once in each week in some newspaper published and of general circulation in the county where the proceeding is had, and each publication of the same shall show at the top thereof the date of the first publication; and except as modified by this section, the proceeding of publication of the summons shall in all respects be governed by the provisions of Title 15 relating to publication of summons. Personal service on any defendant outside of the state shall be of the same effect as service within the state and shall dispense with necessity of publication as to such defendant.
SDCL 21-35-10