25 CFR §161.602

1. (a)If a grazing permit is not used by the permittee for a 2-year period, BIA may cancel the permit upon the recommendation of the Grazing Committee and with the concurrence of the Resources Committee under § 161.606(c). Non-use consists of, but is not limited to, absence of livestock on the range unit, and/or abandonment of a permittee's grazing permit.
2. (b)Unused grazing permits or portions of grazing permits that are set aside for range recovery will not be cancelled for non-use.