December 4th, 2012 - Jennifer at Devil's Gate
The actual Devil's Gate is the break in the rocks behind the sign.
From Wikipedia: "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.
Once the Union Pacific Railroad was extended to Benton, six miles east of present day Sinclair, Wyoming, the Mormon Trail was rerouted through Whiskey Gap in Carbon County to a point 10 miles west of Devil's Gate to rejoin the original trail.
Devil's Gate is a remarkable example of superposed or an antecedent drainage stream. The Sweetwater River cuts a narrow 100-meter deep slot through a granite ridge, yet had it flowed less than a kilometer to the south, it could have bypassed the ridge completely. The gorge was cut because the landscape was originally buried by valley fill sediments. The river cut downward and when it hit granite, kept on cutting. It was a matter of pure chance that the river hit the buried ridge where it did."
From Photo a Day 2012