In Pittsburgh you’ll make the choice to stay on the main route or to follow the Philadelphia Alternate. The route uses the Great Allegheny Passage, a multi-use trail that primarily follows railroad corridors from Pittsburgh to Cumberland. It traverses four tunnels; the longest is the Big Savage Tunnel at 3,294 feet. Grades along the trail are less than 2 percent. In Cumberland the route continues onto the C&O Canal Trail and follows the Potomac River eastward along the Maryland/West Virginia state border. At Hagerstown the route heads northeast past Gettysburg National Military Park, crosses the Susquehanna River, and enters Lancaster County, known as “Pennsylvania Dutch Country.” Click on enlargement for detail. Map section includes portions of the C & O Canal and Great Allegheny Gap trail.