SDCL § 7-8-15: Chair and vice chair--Election--Vacancy--Duties.

At the first meeting of the board of county commissioners in each year, the board shall elect a chair and vice chair. The chair shall continue to serve as chair until a successor is elected. If there is a vacancy for the chair or vice chair from any cause, the board shall elect another chair or vice chair.

The chair or, in the chair's absence, the vice chair shall preside at the meetings of the board and sign all orders and claims approved by the board.