Public Law 95-625, approved November 10, 1978, (92 Stat. 3511) amended the Act to create a new category of National Historic Trails, to closely follow original routes of national historic significance.
National Recreation Trails may be established by the Secretaries of Interior or Agriculture on land wholly or partly within their jurisdiction, with the consent of the involved State(s), and other land managing agencies, if any. National Scenic and National Historic Trails may only be designated by an Act of Congress.
As of January 1, 1989, segments of 12 National Trails cross units of the National Wildlife Refuge System.