43 C.F.R. § 2561.0-8

(a) A Native may be granted a single allotment of not to exceed 160 acres of land. All the lands in an allotment need not be contiguous but each separate tract of the allotment should be in reasonably compact form.

(b) In areas where the rectangular survey pattern is appropriate, an allotment may be in terms of 40-acre legal subdivisions and survey lots on the basis that substantially continuous use and occupancy of a significant portion of such smallest legal subdivision shall normally entitle the applicant to the full subdivision, absent conflicting claims.

(c) Allotments may be made in national forests if founded on occupancy of the land prior to the establishment of the particular forest or if an authorized officer of the Department of Agriculture certifies that the land in the application for allotment is chiefly valuable for agricultural or grazing purposes.

(d) Lands in applications for allotment and allotments that may be valuable for coal, oil, or gas deposits are subject to the regulations of § 2093.4 of this chapter.