16 U.S.C. § 679
The Secretary of the Interior is authorized and directed to issue to the State of South Dakota patents conveying title, but reserving the minerals therein, to any unpatented lands of the United States held or claimed by virtue of locations made prior to March 3, 1925, under the United States general mining laws, within the Custer State Park, not exceeding a total of two thousand acres, upon payment to the United States of $1.25 per acre therefor, and upon evidence being furnished that all claim, right, title, and interest of such claimants have been transferred to the State or have been abandoned. Patents so issued to the State of South Dakota shall be conditioned upon the lands being used for park purposes, and provide for the reversion of the lands of the United States in the event of failure to so hold and use. The United States reserves all coal, oil, gas, or other minerals in the lands patented under this section with the right, in case any of said patented lands are found by the Secretary of the Interior to be more valuable for the minerals therein than for park purposes, to provide, by special legislation, having due regard for the rights of the State of South Dakota, for the disposition and extraction of the coal, oil, gas or other minerals therein. The provisions of this section are limited to lands lying within the limits of the Custer State Park, within townships 3 and 4 south, range 6 east, and the east one-third of townships 3 and 4 south, range 5 east, Black Hills meridian.
16 U.S.C. § 679