Okla. Const. art. XI, § 2

All proceeds of the sale of public lands that have heretofore been or may be hereafter given by the United States for the use and benefit of the common schools of this State, all such per centum as may be granted by the United States on the sales of public lands, the sum of five million dollars appropriated to the State for the use and benefit of the common schools in lieu of sections sixteen and thirty-six, and other lands of the Indian Territory, the proceeds of all property that shall fall to the State by escheat, the proceeds of all gifts or donations to the State for common schools not otherwise appropriated by the terms of the gifts, and such other appropriations, gifts, or donations as shall be made by the Legislature for the benefit of the common schools, shall constitute the permanent school fund, the income from which shall be used for the maintenance of the common schools in the State. The principal shall be deemed a trust fund held by the State, and shall forever remain inviolate. It may be increased, but shall never be diminished. The State shall reimburse said permanent school fund for all losses thereof which may in any manner occur, and no portion of said fund shall be diverted for any other use or purpose.