16 U.S.C. § 460aa-2
Except as provided in section 460aa-3 of this title, the Secretary is authorized to acquire by donation, purchase with donated or appropriated funds, exchange, bequest, or otherwise any lands, or lesser interests therein, including mineral interests and scenic easements, which he determines are needed for the purposes of this subchapter: Provided, That acquisitions of lands or interests therein for access to and utilization of public property, and for recreation and other facilities, shall not exceed five per centum of the total acreage of all private property within the recreation area as of August 22, 1972.
As used in this subchapter the term "scenic easement" means the right to control the use of land in order to protect the esthetic values for the purposes of this subchapter, but shall not preclude the continuation of any use exercised by the owner as of August 22, 1972.
In exercising this authority to acquire lands, the Secretary shall give prompt and careful consideration to any offer made by an individual owning any land, or interest in land, within the boundaries described in section 460aa(b) of this title. In considering such offer, the Secretary shall take into consideration any hardship to the owner which might result from any undue delay in acquiring his property.
The Secretary may utilize condemnation proceedings without the consent of the owner to acquire private lands or interests therein pursuant to this section only in cases where, in his judgment, all reasonable efforts to acquire such lands or interests therein by negotiation have failed, and in such cases he shall acquire only such title as, in his judgment, is reasonably necessary to accomplish the objectives of this subchapter.
In exercising his authority to acquire property by exchange, the Secretary may accept title to any non-Federal property, or interests therein, located within the recreation area and, notwithstanding any other provision of law, he may convey in exchange therefor any federally owned property within the State of Idaho which he classifies as suitable for exchange and which is under his administrative jurisdiction. The values of the properties so exchanged shall be approximately equal or, if they are not approximately equal, they shall be equalized by the payment of cash to the grantor or to the Secretary as the circumstances require. In the exercise of his exchange authority, the Secretary may utilize authorities and procedures available to him in connection with exchanges of national forest lands.
Nothing in this subchapter shall be construed as limiting the authority of the Secretary to acquire mineral interests in lands within the recreation area, with or without the consent of the owner. Upon acquisition of any such interest, the lands and/or minerals covered by such interest are by this subchapter withdrawn from entry or appropriation under the United States mining laws and from disposition under all laws pertaining to mineral leasing and all amendments thereto.
Any land or interest in land owned by the State of Idaho or any of its political subdivisions may be acquired only by donation or exchange.
Notwithstanding any other provision of law, any Federal property located within the recreation area may, with the concurrence of the agency having custody thereof, be transferred without consideration to the administrative jurisdiction of the Secretary for use by him in carrying out the purposes of this subchapter. Lands acquired by the Secretary or transferred to his administrative jurisdiction within the recreation area shall become parts of the recreation area and of the national forest within or adjacent to which they are located.
Except as otherwise provided, the Secretary shall have the authority to use condemnation as a means of acquiring a clear and marketable title, free of any and all encumbrances.
16 U.S.C. § 460aa-2