25 U.S. Code § 61 - Estimates for personal services in Indian Office
Annual estimates in detail shall be submitted for all personal services required in the Indian Office, and it shall not be lawful to employ in said office any personal services other than those specifically appropriated for in the legislative, executive, and judicial appropriation Acts, except temporary details of field employees for service connected solely with their respective employments.
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.