 The Appalachian Trail turns south onto PA 248 at this point.When Pennsylvania first legislated routes in 1911, what is now PA 873 was incorporated as part of Legislative Route 163, which ran between Allentown and Mauch Chunk (present-day Jim Thorpe).With the creation of the U.S. Highway System in 1926, the section of road between Schnecksville and Lehigh Gap was designated as part of US 309, a route that ran from Philadelphia north to Wilkes-Barre.