40 CFR § 35.582
Definitions
June 9, 2020
Federal Indian reservation. All land within the limits of any Indian reservation under the jurisdiction of the United States Government, notwithstanding the issuance of any patent, and, including rights-of-way running through the reservation.
Tribe. Any Indian Tribe, band, group, or community recognized by the Secretary of the Interior, exercising governmental authority over a federal Indian reservation.