43 U.S. Code § -
(a) Establishment, maintenance and regulation
The Secretary may establish and maintain, and regulate the use of, stock driveways in districts and may charge a fee for or permit the free use of such driveways.
(b) Grazing of livestock free of charge
The Secretary may permit any person, including prospectors and miners, to graze free of charge a small number of livestock upon any land included within any grazing district.
(c) Grazing allotments to Eskimos or other native or half-breed
The Secretary may in his discretion grant a permit or lease for a grazing allotment without charge on unallotted public lands to any Eskimo or other native or half-breed. Whenever such native or half-breed grazes his livestock through cooperative agreement on allotment held by other lessee or permittee, any grazing fees charged for said allotment shall be reduced in proportion to the relative number of such native owned livestock to the total number on said allotment.