Best Solitary Trail: Maah Daah Hey Trail (Theodore Roosevelt National Park, North Dakota)
Credit: Ryan Creary / Getty Images

Difficulty: Moderate

Trail running meets adventure travel on the Maah Daah Hey (rough translation from the Mandan Indian language: "be here a long time"), a 97-mile singletrack passage through the North Dakota badlands, mostly in the two sections of Theodore Roosevelt National Park and the Little Missouri National Grasslands. As the trail snakes over rolling hills, rugged buttes, and treeless prairies, a highlight reel of Old West clichés unfolds: coyotes, prairie dogs, wild mustangs, bighorn sheep, and endless horizons.