The Allegheny Highlands Trail of Maryland is a 20.47-mile rail trail in western Maryland that runs from the C&O Canal in Cumberland to the Mason–Dixon line, where it joins the Allegheny Highlands Trail of Pennsylvania. As part of the larger Great Allegheny Passage between Pittsburgh and Washington, DC, it occupies the former Connellsville extension of the Western Maryland Railway. Between Cumberland and Frostburg, active track still runs alongside part of the trail for the Western Maryland Scenic Railroad, creating a rare and unusually direct connection between the region’s railroad heritage and its modern use as a protected recreational route.