S.D. Codified Laws § 12-22-22
Whenever it shall come to the attention of the Supreme Court that two or more contests are pending involving nomination or election to the same office or position, or the same submitted or referred question, the court may, on its own motion, or on the motion of any interested person and on reasonable notice to the parties, make an order, under its power of supervision of lower courts, directing that such proceedings be consolidated, and designating the circuit court in which further proceedings are to be had, with such provisions as the court considers necessary to safeguard the rights of the parties. It shall be the duty of any attorney appearing in any such case, upon learning of the pendency of any such other proceedings, to call the same to the attention of the Supreme Court. Any circuit judge before whom any such case is pending, upon learning of the pendency of any such other case, shall proceed no further, but shall at once notify the Supreme Court of the situation.
SDCL 12-22-22