1. Short title This Act may be cited as the Route 66 National Historic Trail Designation Act . 2. Designation of the Route 66 National Historic Trail Section 5(a) of the National Trails System Act ( 16 U.S.C. 1244(a) ) is amended by adding at the end the following: (31) Route 66 National Historic Trail (A) In general The Route 66 National Historic Trail, a trail that includes all the alignments of U.S. Highway 66 in existence between 1926 and 1985, extending along a route of approximately 2,400 miles from Chicago, Illinois, to Santa Monica, California, as generally depicted on the map entitled Route 66 National Historic Trail, Proposed Route , numbered P26/141,279, and dated December 2017. (B) Availability of map The map described in subparagraph (A) shall be on file and available for public inspection in the appropriate offices of the National Park Service, Department of the Interior. (C) Administration The Route 66 National Historic Trail shall be administered by the Secretary of the Interior, acting through the Director of the National Park Service. Such administration shall be conducted in a manner that respects and maintains the idiosyncratic nature of the Route 66 National Historic Trail. (D) Land Acquisition The United States may not acquire for the Route 66 National Historic Trail any land or interest in land— (i) outside the exterior boundary of any federally managed area without the consent of the owner of the land or interest in land