The twin deck-plate girder bridges on either side of the Pinkerton Tunnel carry the Great Allegheny Passage over the Casselman River twice in about a third of a mile. Over that span, the river bends in a tight hairpin, forming a narrow peninsula called the Pinkerton Horn, and drops significantly, so that while the 242-foot Pinkerton Low Bridge is just 30 feet over the water, the 543-foot Pinkerton High Bridge is 100 feet above the receding whitewater. River access is relatively easy from the east end of the low bridge, as are views of Amtrak’s Capitol Limited and freight trains on the active lines across the river..
These bridges were constructed in 1911 for the Western Maryland Railway’s extension into Pennsylvania, and were abandoned in the 1970’s. They were redecked for trail use in 1994.
Open dawn to dusk. The closest parking is along the GAP at Markleton, Pa., about two miles west.