Great Allegheny Passage

Routes and locations linked to the Great Allegheny Passage (GAP) trail. The GAP is a rail trail in Maryland and Pennsylvania. It is the central trail of a network of long-distance hiker-biker trails covering hundreds of miles through the Allegheny region of the Appalachian Mountains, connecting Washington, D.C. to Pittsburgh, Pennsylvania and beyond.The multi-use trail, suitable for biking and walking, occupies abandoned corridors of the Baltimore and Ohio Railroad, Pittsburgh and Lake Erie Railroad, Union Railroad and the Western Maryland Railway.