20 U.S.C. § 5606

(a) Establishment of Trust Fund There is established in the Treasury of the United States a trust fund to be known as the “Morris K. Udall and Stewart L. Udall Trust Fund” to be administered by a Foundation. The Trust Fund shall consist of amounts appropriated to it pursuant to section 5609(a) of this title and amounts credited to it under subsection (b). (b) Investment of Trust Fund assets (1) 1 1 So in original. No par. (2) has been enacted. In general .— It shall be the duty of the Secretary of the Treasury to invest, at the direction of the Foundation Board, in full the amounts appropriated to the Trust Fund. Such investments shall be in public debt securities with maturities suitable to the needs of the Trust Fund. Investments in public debt securities shall bear interest “at rates determined by the Secretary of the Treasury taking into consideration the current average market yield on outstanding marketable obligations of the United States” of comparable maturity. Beginning on October 1, 2023 , and thereafter, interest earned from investments made with any new appropriations to the Trust Fund shall only be available subject to appropriations and is authorized to be appropriated to carry out the provisions of this chapter.