The South Dakota Department of Environment and Natural Resources is responsible for maintaining a state water plan, intended to implement state policies for water management. A portion of the plan is reserved for rivers designated as wild, scenic, or recreational by the Board of Water and Natural Resources. No development may occur that is detrimental to the natural and scenic beauty of the designated river.
The Missouri River has a national designation as a recreational river (http://www.nps.gov/mnrr/index.htm). It is unclear whether any other rivers are currently designated as wild, scenic, or recreational in South Dakota.