In addition to the much vaunted Triple Crown trails , the Appalachian Trail (3,000 km), the Pacific Crest Trail (4,250 km), or the Continental Divide Trail (4,500 km), which go over relatively isolated, steep mountain ranges, you might check out the NCT.
The North Country Trail (NCT) connects America’s red plaid nation, wandering 4600 miles through America’s rugged northern heartlands. Stretching across seven states, this longest National Scenic Trail is brought to local communities through the dedication and hard work of volunteers. The NCT runs from New York to North Dakota.