Devil's Gate (Wyoming) is a natural rock formation, a gorge on the Sweetwater River a few miles southwest of Independence Rock. The site, significant in the history of western pioneers, was a major landmark on the Mormon Trail and the Oregon Trail although the actual routes of travel did not pass through the very narrow gorge. The earliest surviving photograph of this landmark was made in 1858 by Samuel C. Mills, a photographer with the Captain Simpson Expedition. It is accessible today from Wyoming Highway 220 (mile marker 57) between Casper and Muddy Gap, near the Mormon Handcart Historic Site and Martin's Cove.