National Parks near Fourth Gap Trail, Union County, Pennsylvania Fourth Gap Trail Main Page HIGH QUALITY TOPO MAP, CLICK HERE More Information about Fourth Gap Trail, Union County, Pennsylvania Nearest metro area is Lewisburg, Pennsylvania Click here for more outdoors activities near Lewisburg, Pennsylvania General Camping Information List of nearby National Parks: Catoctin Mountain Park, Thurmont - MD, 77.1 miles away Appalachian National Scenic Trail, Harpers Ferry - WV, 98.4 miles away Potomac Heritage National Scenic Trail, McLean - VA, 98.4 miles away Glen Echo Park, McLean - VA, 107.4 miles away Greenbelt Park, Greenbelt - MD, 107.4 miles away * Distances listed are direct linear distances, actual travel distance may be different. Go to Pennsylvania Outdoors Index