Uncontested mining leases for minerals other than oil and gas shall be made on forms1 prescribed by the Department, for a period of 15 years with the right of renewal on such terms as the superintendent may prescribe, and shall be subject only to approval by the Area Director. See provisions of the act of February 14, 1920 (41 Stat. 408). Any persons aggrieved by any decision or order of the Area Director approving, rejecting, or disapproving any such lease may appeal from the same to the Secretary of the Interior within 30 days from the date of such decision or order.