25 C.F.R. § 1000.435
The appropriate Assistant Secretary will decide an appeal of any initial decision made by a bureau head (see § 1000.433 ). If the Tribe/Consortium has appealed the bureau's initial adverse decision of the bureau to the bureau head and the bureau head's decision on initial appeal is contrary to the Tribe's/Consortium's request for relief, or the bureau head fails to make a decision within 30 days of receipt by the bureau of the Tribe's/Consortium's initial request for review and any accompanying statement and documentation, the Tribe's/Consortium's appeal will be sent automatically to the appropriate Assistant Secretary for decision. The Assistant Secretary must either concur with the bureau head's decision or issue a separate decision within 60 days of receipt by the bureau of the Tribe's/Consortium's initial request for review and any accompanying statement and documentation. The decision of the Assistant Secretary is final for the Department.
25 C.F.R. §1000.435