The administration, protection, and development of the aforesaid park shall be exercised under the direction of the Secretary of the Interior by the National Park Service, subject to the provisions of the Act of , entitled “An Act to establish a National Park Service, and for other purposes,”  as amended: , That the provisions of the Federal Power Act [ et seq.] shall not apply to this park: , That the minimum area to be administered and protected by the National Park Service shall be, for the said Mammoth Cave National Park, twenty thousand acres: , That no general development of said area shall be undertaken until a major portion of the remainder in such area, including all the caves thereof, shall have been accepted by said Secretary, and he shall have established a schedule of fees for admission to such caves.116 U.S.C. 791aAugust 25, 19161916-08-25ProvidedAnd provided furtherProvided further