All lands allotted to Indians in severalty, except allotments made to members of the Five Civilized Tribes and Osage Indians in Oklahoma, may by said allottee be leased for mining purposes for any term of years as may be deemed advisable by the Secretary of the Interior; and the Secretary of the Interior is authorized to perform any and all acts and make such rules and regulations as may be necessary for the purpose of carrying the provisions of this section into full force and effect: Provided, That if the said allottee is deceased and the heirs to or devisees of any interest in the allotment have not been determined, or, if determined, some or all of them cannot be located, the Secretary of the Interior may offer for sale leases for mining purposes to the highest responsible qualified bidder, at public auction, or on sealed bids, after notice and advertisement, upon such terms and conditions as the Secretary of the Interior may prescribe. The Secretary of the Interior shall have the right to reject all bids whenever in his judgment the interests of the Indians will be served by so doing, and to readvertise such lease for sale.
25 U.S. Code § 396 - Leases of allotted lands for mining purposes
1955—Act Aug. 9, 1955, authorized Secretary of the Interior to lease allotted lands for mining purposes where the allottee is deceased and the heirs to or devisees of any interest in the allotment either have not been determined or cannot be located.
Pub. L. 106–462, title II, § 201, Nov. 7, 2000, 114 Stat. 2007, authorized the Secretary of the Interior to approve oil or gas leases affecting individually owned Navajo Indian allotted lands in certain circumstances and defined pertinent terms with respect to such leases.
Pub. L. 105–188, § 1, July 7, 1998, 112 Stat. 620, as amended by Pub. L. 106–67, § 1(2), Oct. 6, 1999, 113 Stat. 979, authorized Secretary of the Interior to approve any mineral lease or agreement that affects individually owned land located within Fort Berthold Indian Reservation in North Dakota or certain former Indian reservations located in Oklahoma upon consent of majority interest and best interest determination.