S.D. Codified Laws § 41-2-40

No lands may be considered for disposal under §§ 41-2-39 to 41-2-46, inclusive, unless the lands lie outside the fence to be constructed under § 41-17-26. No lands may be disposed of under §§ 41-2-39 to 41-2-46, inclusive, unless the Department of Game, Fish and Parks and the Game, Fish and Parks Commission first determine that the lands are surplus and not needed for present or future development of the trail, nor for other transportation uses.