S.D. Codified Laws § 16-6-32

Retired justices and judges, with their consent, may be authorized by the Chief Justice to preside in any action or proceeding, or over any term of court, in the circuit court and when so authorized and acting, the orders, judgments, and decrees of that court entered by him are as effectual for all purposes as though made by a regularly elected or appointed judge. The Supreme Court shall provide for the reimbursement of their expenses.