25 U.S. Code § 635 - Disposition of lands
Any restricted Indian lands owned by the Navajo Tribe, members thereof, or associations of such members, or by the Hopi Tribe, members thereof, or associations of such members, may be leased by the Indian owners, with the approval of the Secretary of the Interior, for public, religious, educational, recreational, or business purposes, including the development or utilization of natural resources in connection with operations under such leases. All leases so granted shall be for a term of not to exceed twenty-five years, but may include provisions authorizing their renewal for an additional term of not to exceed twenty-five years, and shall be made under such regulations as may be prescribed by the Secretary. Restricted allotments of deceased Indians may be leased under this section, for the benefit of their heirs or devisees, in the circumstances and by the persons prescribed in section 380 of this title. Nothing contained in this section shall be construed to repeal or affect any authority to lease restricted Indian lands conferred by or pursuant to any other provision of law.
Notwithstanding any other provision of law, land owned in fee simple by the Navajo Tribe may be leased, sold, or otherwise disposed of by the sole authority of the Navajo Tribal Council, in any manner that similar land in the State in which such land is situated may be leased, sold, or otherwise disposed of by private landowners, and such disposition shall create no liability on the part of the United States.
The Secretary of the Interior is authorized to transfer, upon request of the Navajo Tribal Council, to any corporation owned by the tribe and organized pursuant to State law, or to any municipal corporation organized under State law, legal title to or a leasehold interest in any unallotted lands held for the Navajo Indian Tribe, and thereafter the United States shall have no responsibility or liability for, but on request of the tribe shall render advice and assistance in, the management, use, or disposition of such lands.