When title to such lands, structures, and other property in the Cumberland Gap-Cumberland Ford areas, being portions of the Warriors Path of the Indians and Wilderness Road of Daniel Boone, within Bell and Harlan Counties, Kentucky; Lee County, Virginia; and Claiborne County, Tennessee; as may be determined by the Secretary of the Interior as necessary or desirable for national historical park purposes, shall have been vested in the United States, such area or areas shall be, and they are, established, dedicated, and set apart as a public park for the benefit and inspiration of the people and shall be known as the Cumberland Gap National Historical Park: Provided, That the United States shall not purchase by appropriation of public moneys any lands within the aforesaid areas.