AllNinety percent of the money received from the forest service of the United States under the Agricultural Act approved June 30, 1906, as receipts from the Black Hills National Forest, shall be is distributed annually to the counties of Lawrence, Meade, Pennington, Custer, and Fall River, for the benefit of the public roads and public schools of such counties, in proportion to the area of such Black Hills National Forest in each county. The remaining money is used to fund the Native American achievement schools grant program established under § 1-54-13.