25 U.S. Code § 2 - Duties of Commissioner
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.
All supervisory and appellate powers and duties in regard to Indian affairs theretofore vested in Secretary of the Treasury were thereafter to be exercised and performed by Secretary of the Interior under provisions of section 1 of act July 27, 1868, ch. 259, 15 Stat. 228.