43 CFR § 4300.53
Can BLM reduce the size of the land in my permit?
June 11, 2020
Yes. BLM may reduce it at any time but must notify you at least 30 days before taking this action. BLM can reduce the area when:
(a) BLM determines that the area is too large for the number of reindeer you are grazing; or
(b) When disposal, withdrawal, natural causes, such as drought or fire, or any other reason in §4300.50 so requires.