S.D. Codified Laws § 7-27-3
It shall be lawful for the county commissioners in their discretion to purchase, including by contract for deed or lease with purchase option, or lease or acquire by gift, bequest, or otherwise, land in such county and to erect or lease and maintain, repair, remodel, and otherwise improve at any time suitable buildings thereon for county fair purposes and to conduct a county fair thereon, employing a secretary or manager therefor, and to do any and all things in the premises which are ordinarily done by the manager conducting county agricultural and industrial fairs, or to delegate any and all such powers for the conduct of such fair to a county fair board or nonprofit operating corporation as provided by §§ 7-27-10 and 7-27-11, including the right to charge for entrance thereto and to offer premiums for exhibits thereat. In the discretion of the county commissioners county fair purposes may include buildings, equipment, and other facilities for 4-H achievements days or any other 4-H activity, and any funds provided by this chapter may be allocated and used for such expenditures.
SDCL 7-27-3