S.D. Codified Laws § 8-1-10
Following the hearing required in § 8-1-9, the proposed reorganization, division, or merger shall be decided by the voters of the affected civil townships and the affected portions of unorganized congressional townships by ballot at the next regular township election. Any registered voter residing in the affected portion of an unorganized congressional township shall be afforded the opportunity to vote in conjunction with the election held in the township to which the unorganized area is proposed to be attached, except that the votes of such persons shall be tabulated separately by officials of the township. The board of supervisors of each affected township shall publish notice of election in the same manner as provided in chapter 8-3 for publication of notice of the annual township meeting. If any portion of an unorganized congressional township is proposed to be attached to a civil township, the affected civil township shall also publish its notice in any official newspaper of the county that is not an official newspaper of the township. If a majority of the votes cast in each of the affected townships and in the affected portion of each affected unorganized congressional township are in favor of the proposed reorganization, division, or merger, the proposal shall be implemented as provided in this chapter. If no vote is cast by any resident of an affected portion of a civil township or unorganized congressional township, the board of county commissioners of the county in which the affected portion is located shall determine the status of the affected portion for purposes of deciding the results of the election in the affected portion.
SDCL 8-1-10