25 C.F.R. § 215.9
Whenever a lease award to a proposed lessee has been approved by the Secretary of the Interior, as provided in §§ 215.7 and 215.8 , the lease contract shall be executed by the Indian owner of the land, if he be an adult and not incompetent as defined in § 215.0(c) . Before any lease is entered into by the Indian owners or is approved by the Secretary of the Interior, all the adult and competent owners or co-owners of the tract of land which it is proposed to lease, shall be furnished by the Bureau such geological reports as may be available or that can be secured from the representative of the Geological Survey showing the estimated mineral reserves on said property, the estimated reasonable value of such property for mining purposes, and such other data as might reasonably be necessary to fully advise the owners of said property of the then present status and mining value of their lands. If the Quapaw or other Indian owner of the land is a minor, or is otherwise an incompetent as defined in the regulations in this part, the lease contract shall be executed by the superintendent for and on behalf of such minor or such incompetent. The leases executed, either by the Indian owner of the land or by the superintendent in his behalf, shall be subject to the approval of the Secretary of the Interior and shall be effective only upon such approval.
25 C.F.R. §215.9