S.D. Codified Laws § 47-14B-17
Service of legal process upon any foreign business trust shall be made by delivering a copy personally to any trustee of the foreign business trust in the state or the registered agent of the foreign business trust in the state, or by leaving it at the dwelling house or usual place of abode in the state of any such trustee or registered agent (if the registered agent be an individual), or at the registered office or other place of business of the foreign business trust in the state. If the registered agent be a corporation, service of process upon it as such may be made by serving, in the state, a copy thereof on the president, vice president, secretary, assistant secretary, or any director of the corporate registered agent. Service by copy left at the dwelling house or usual place of abode of any trustee or registered agent, or at the registered office or other place of business of the foreign business trust in the state, to be effective, must be delivered thereat at least six days before the return date of the process, and in the presence of an adult person, and the officer serving the process shall distinctly state the manner of service in the officer's return thereto. Process returnable forthwith must be delivered personally to the trustee or registered agent.
SDCL 47-14B-17