Potomac Heritage are official units of the NPS; though their enabling legislation does not distinguish them, these have more direct administration. The NPS manages its other three trails more as a coordinator with local partners than as an administrator. The NPS manages its scenic trails like its other areas, as long, linear parks. Five trails are overseen by the U.S. Forest Service. In 2022 Arlette Laan, whose trail name was "Apple Pie," became the first woman known to have completely hiked all eleven of the national scenic trails. National Historic Trails The 21 national historic trails are designated to protect the courses of significant overland or water routes that reflect the history of the nation. They represent the earliest European travels in the country in Chesapeake Bay and on Spanish royal roads; the nation's struggle for independence on the Overmountain Victory National Historic Trail and Washington–Rochambeau Revolutionary Route; westward migrations on the Oregon, California, and Mormon Trails, which traverse some of the same route; and the development of continental commerce on the Santa Fe Trail, Old Spanish Trail, and Pony Express. They also memorialize the forced displacement and hardships of the Native Americans on the Trail of Tears and Nez Perce National Historic Trail. Their routes follow the nationally significant, documented historical journeys of notable individuals or groups but are not necessarily meant to be continuously traversed today; they are largely networks of partner sites along marked auto routes rather than the exact non-motorized trails as originally used. Interpretative sites are often at other areas of the National Park System along the trails, as well as locally operated museums and sites. The National Historic Trails Interpretive Center in Wyoming is on the Oregon, California, Mormon Pioneer, and Pony Express National Historic Trails and has exhibits on Western emigration. Nine are administered by the NPS National Trails Office in Santa Fe and Salt Lake City. National historic trails were authorized under the National Parks and Recreation Act of 1978 (), amending the National Trails System Act of 1968. They have a total length of approximately ; many trails include several branches making them much longer than a single end-to-end distance. Connecting or side trails The act also established a category of trails known as connecting or side trails. Though there are no guidelines for how these are managed, these have been designated by the secretary of the interior to extend trails