This bill, titled the "Route 66 National Historic Trail Designation Act," amends the National Trails System Act to formally establish the Route 66 National Historic Trail . This designation encompasses all alignments of U.S. Highway 66 that existed between 1926 and 1985, spanning approximately 2,400 miles from Chicago, Illinois, to Santa Monica, California. The trail will be administered by the Secretary of the Interior through the National Park Service, with a directive to respect its unique character and conduct active, meaningful, and timely consultation with affected Indian Tribes for any activities with substantial direct impacts. Significantly, the legislation includes several limitations on federal authority regarding the trail. It prohibits the use of eminent domain or condemnation for land acquisition and restricts acquisitions to an average of one-quarter mile on either side, requiring owner consent for land outside federally managed areas. The bill explicitly states that the designation does not create buffer zones, impede energy development or infrastructure, or classify the trail as "lands in the National Park System" for certain purposes. Furthermore, it clarifies that the designation does not alter existing authority for granting easements or rights-of-way, nor does it impose new federal permit requirements solely due to its inclusion in the National Trails System.