25 C.F.R. § 162.012
What are the consent requirements for a lease?
(a) For fractionated tracts:
(1) Except in Alaska, the owners of the following percentage of undivided trust or restricted interests in a fractionated tract of Indian land must consent to a lease of that tract:
| If the number of owners of the undivided trust or restricted interest in the tract is . . . | Then the required percentage of the undivided trust or restricted interest is . . . |
|---|---|
| (i) One to five, | 90 percent; |
| (ii) Six to 10, | 80 percent; |
| (iii) 11 to 19, | 60 percent; |
| (iv) 20 or more, | Over 50 percent. |
(2) Leases in Alaska require consent of all of the Indian landowners in the tract.
(3) If the prospective lessee is also an Indian landowner, his or her consent will be included in the percentages in paragraphs (a)(1) and (2) of this section.
(4) Where owners of the applicable percentages in paragraph (a)(1) of this section consent to a lease document:
(i) That lease document binds all non-consenting owners to the same extent as if those owners also consented to the lease document; and
(ii) That lease document will not bind a non-consenting Indian tribe, except with respect to the tribally owned fractional interest, and the non-consenting Indian tribe will not be treated as a party to the lease. Nothing in this paragraph affects the sovereignty or sovereign immunity of the Indian tribe.
(5) We will determine the number of owners of, and undivided interests in, a fractionated tract of Indian land, for the purposes of calculating the percentages in paragraph (a)(1) of this section based on our records on the date on which the lease is submitted to us for approval.
(b) Tribal land subject to a tribal land assignment may only be leased with the consent of the tribe.