When we finished cycling the Great Allegheny Passage (GAP) the other day, we were at the western terminus of the Chesapeake & Ohio (C&O) Canal Towpath cycling route. Unlike the GAP which is a converted railroad line, the C&O trail is a towpath that follows the course of the Potomac River 184.5 miles from Cumberland, Maryland to Georgetown, Washington, DC. The towpath was originally created to aid commerce between the US capital and its expanding western frontier. Today, it’s a quiet, wooded multi-use trail along the remains of the canal.