The Devil's Path is a hiking trail in the Catskill Mountains of New York. Though only 24.2 miles long, the trail boasts 8,000-9,000 vertical feet of climbing, and is considered by many to be the toughest hiking trail in the Eastern US. Wikipedia has detailed description of the trail.

The Northville Placid Trail (NPT) is a 142 mile route running between Waterfront Park in Northville, NY to the Lake Placid History Museum (forme

The Mason Dixon Trail connects the Appalachian Trail with the Brandywine Trail. This 193 mile long trail starts at Whiskey Springs, on the Appalachian Trail, in Cumberland County, PA and heads east towards the Susquehanna River, passing through Pinchot State Park en route. The trail then follows the west bank of the Susquehanna south to Havre de Grace in Maryland Across the river, the M-DT continues east, passes through Elk Neck State Forest, then on to Iron Hill Park in Delaware, north along the Christina River and White Clay Creek to the White Clay Creek Preserve.