Blackwater Natural Bridge is a remote natural arch in Shoshone National Forest in northwestern Wyoming, perched on a ridge at 10,777 feet near Coxcomb Mountain and above the headwaters of Blackwater Creek. It is significant both for its isolation and because its true size remains uncertain: no official measurement has been completed, and estimates range from 70 to 100 feet to claims that it may be among the world’s largest natural arches. Reaching it requires a long off-trail hike from trailheads connected to U.S. Routes 14, 16, and 20 near Cody, passing the site of the devastating 1937 Blackwater fire.