S.D. Codified Laws § 11-6-10
The legislative body of an incorporated municipality and a board of county commissioners may jointly exercise the comprehensive planning and zoning powers granted in this chapter and chapters 11-2 and 11-4 in a joint jurisdictional area beyond the municipal corporate limits. The joint jurisdictional area, not to exceed six miles, shall be delineated in a comprehensive plan but in no instance may the area extend beyond a line equidistant from the corporate limits of any other municipality unless otherwise agreed to by a majority vote of the governing body of each municipality having a planning commission. Nothing contained in this chapter may be construed to amend or repeal any provisions of chapter 49-34A.
The county and city planning commissions shall meet jointly and hold at least one public hearing on the comprehensive plan. Notice of the time and place of the hearing shall be given once by either the city or county at least ten days in advance by publication in a legal newspaper. Following the public hearing, each planning commission shall submit a recommendation to their respective governing body.
SDCL 11-6-10