43 C.F.R. § 4300.59 If I want to assign my permit to another party, when must I notify BLM?
Title 43 - Public Lands: Interior
You must file a proposed assignment of your permit, in whole or in part, in duplicate with BLM within 90 days of the assignment execution date. No particular format is required. The assignment is effective when BLM approves it.
Title 43: Public Lands: Interior
PART 4300—GRAZING ADMINISTRATION; ALASKA; REINDEER; GENERAL
Assigning Your Permit to Another Party
§ 4300.59 If I want to assign my permit to another party, when must I notify BLM?

