16 U.S.C. § 441k

Subject to the provisions of subsection (b) hereof, the Secretary of the Interior may, within the boundaries of the park, acquire lands and interests in lands by donation, purchase with donated or appropriated funds, or exchange, except that any lands or interests in lands owned by the State of South Dakota, a political subdivision thereof, or the Oglala Sioux Tribe of South Dakota may be acquired only with the consent of owner. Notwithstanding any other provision of law, lands and interests in lands located within the park under the administrative jurisdiction of any other Federal agency may be transferred to the administrative jurisdiction of the Secretary without a transfer of funds.

lAs to lands located within the boundaries of the park but outside the boundaries of the gunnery range referred to in section 441 of this title, the Secretary of the Interior may acquire only rights-of-way and scenic easements.