25 U.S. Code § 304 - South Dakota Indians; State course of study
On and after July 1, 1950, the course of study taught in any school operated and maintained by the Bureau of Indian Affairs on any Indian reservation in the State of South Dakota shall, upon a majority decision of the parents of children enrolled therein voting at a meeting called for that purpose by the superintendent of the reservation, meet the minimum education requirements prescribed by the department of public instruction for the public schools of that State.
Source(Sept. 7, 1949, ch. 566, 63 Stat. 694.)