25 U.S. Code § 163 - Roll of membership of Indian tribes
The Secretary of the Interior is authorized, wherever in his discretion such action would be for the best interest of the Indians, to cause a final roll to be made of the membership of any Indian tribe; such rolls shall contain the ages and quantum of Indian blood, and when approved by the said Secretary are declared to constitute the legal membership of the respective tribes for the purpose of segregating the tribal funds as provided in section 162  of this title, and shall be conclusive both as to ages and quantum of Indian blood:
 See References in Text note below.
For transfer of functions of other officers, employees, and agencies of Department of the Interior, with certain exceptions, to Secretary of the Interior, with power to delegate, see Reorg. Plan No. 3 of 1950, §§ 1, 2, eff. May 24, 1950, 15 F.R. 3174,64 Stat. 1262, set out in the Appendix to Title 5, Government Organization and Employees.