25 U.S.C. § 161: Deposit in Treasury of trust funds

The Secretary of the Interior is authorized to deposit, in the Treasury of the United States, any and all sums held by him on April 1, 1880 , or which may be received by him, as Secretary of the Interior and trustee of various Indian tribes, on account of the redemption of United States bonds, or other stocks and securities belonging to the Indian trust fund, and all sums received on account of sales of Indian trust lands, and the sales of stocks lately purchased for temporary investment, whenever he is of the opinion that the best interests of the Indians will be promoted by such deposits, in lieu of investments; and the United States shall pay interest semiannually, from the date of deposit of any and all such sums in the United States Treasury, at the rate per annum stipulated by treaties or prescribed by law, and such payments shall be made in the usual manner, as each may become due, without further appropriation by Congress.