54 U.S.C. § 320301: National monuments

The President may, in the President’s discretion, declare by public proclamation historic landmarks, historic and prehistoric structures, and other objects of historic or scientific interest that are situated on land owned or controlled by the Federal Government to be national monuments. The President may reserve parcels of land as a part of the national monuments. The limits of the parcels shall be confined to the smallest area compatible with the proper care and management of the objects to be protected. When an object is situated on a parcel covered by a bona fide unperfected claim or held in private ownership, the parcel, or so much of the parcel as may be necessary for the proper care and management of the object, may be relinquished to the Federal Government and the Secretary may accept the relinquishment of the parcel on behalf of the Federal Government. No extension or establishment of national monuments in Wyoming may be undertaken except by express authorization of Congress.