By using both the Chesapeake and Ohio Canal Trail (C&O Canal), as well as the Great Allegheny Passage Rail-Trail (dubbed “America’s Friendliest Long-Distance Rail-Trail”), you can bike all the way from the Southernmost point in Montgomery County all the way to the Steel City without ever needing to bike on a road. The Chesapeake and Ohio Canal Trail starts in Georgetown and follows the Potomac River to Cumberland, Maryland. Then the Great Allegheny Passage Rail-Trail goes the rest of the way from Cumberland, making its way past the Mason-Dixon Line, through the Appalachian Mountains and finishing up in Downtown Pittsburgh.
The Great Allegheny Passage Rail-Trail is 150 Miles, while the C&O Canal is 184.5 Miles making for a total distance of 334.5 Miles from DC to Pittsburgh.
Images from Britannica and Discovery Bicycle Tours
By Tom Merritt
Doing this today.
Might want to give a shoutout to Ride Allegheny (https://rideallegheny.org/), who ride that route over 4 days. Raising funds for Operation Second Chance, a charity that supports veterans.