25 U.S.C. § 163 — Roll of membership of Indian tribes

The Secretary of the Interior may order a final roll of a tribe's membership, whenever he decides, at his own discretion, that doing so is in the Indians' best interest. The roll must list each member's age and "quantum of Indian blood." This section does not define what "quantum of Indian blood" means. Once the Secretary approves the roll, it legally establishes who counts as a member of that tribe, for the purpose of dividing tribal funds under section 162 of this title. The roll is conclusive on both the members' ages and their blood quantum — meaning those listed facts cannot be challenged afterward. This rule does not apply to the Five Civilized Tribes, the Osage Tribe of Indians, the Chippewa Indians of Minnesota, or the Menominee Indians of Wisconsin.