S.D. Codified Laws § 49-1-8.2
The Public Utilities Commission may appoint an executive director who shall serve at the pleasure of the commission. The executive director shall serve as the chief administrative officer of the commission and shall be directly responsible to all the members of the commission. The executive director shall carry out those functions that have been delegated to him by the commission or any of its members. The executive director may sign all orders, tariffs, and other documents on the commission's behalf and at the request of the commission after their review. At the time of signature the executive director shall indicate on the face of the document that he has been authorized to sign the document at the request of the commission or individual members. The executive director may not conduct or administer the office so as to discriminate against any of the commission members.
SDCL 49-1-8.2