S.D. Codified Laws § 6-17-3
Current with legislation signed by the governor on or before 3/6/2024
No initiated resolution of cooperation may become operative unless approved by a majority of the votes cast in each of the affected local government entities. If so approved, the resolution takes effect one hundred eighty days after the election or other date as specifically stated in the resolution or within one hundred eighty days after the election as the affected local government entities may agree.
SDCL 6-17-3