Devils Tower is an igneous intrusion or laccolith in the Bear Lodge Mountains (part of the Black Hills) near Hulett and Sundance in Crook County, northeastern Wyoming, above the Belle Fourche River. It rises dramatically 1,267 feet (386 m) above the surrounding terrain and the summit is 5,114 feet (1,559 m) above sea level.
In recent years, about 1% of the Monument's 400,000 annual visitors climbed Devils Tower, mostly using traditional climbing techniques.
Geologists Carpenter and Russell studied Devils Tower in the late 19th century and came to the conclusion that it was formed by an igneous intrusion. Modern geologists agree that it was formed by the intrusion of igneous material, but not on exactly how that process took place. Several believe the molten rock comprising the Tower might not have surfaced; others are convinced the tower is all that remains of what once was a large explosive volcano.
In recent years, climbing Devils Tower National Monument has increased in popularity. The first known ascent of Devils Tower by any method occurred on July 4, 1893, and is accredited to William Rogers and Willard Ripley, local ranchers in the area. They completed this first ascent after constructing a ladder of wooden pegs driven into cracks in the rock face. A few of these wooden pegs are still intact and are visible on the tower when hiking along the 1.3-mile (2.1 km) Tower Trail at Devils Tower National Monument. Over the following thirty years many climbs were made using this method before the ladder fell into disrepair. The man most famous for climbing the tower is Fritz Wiessner, who summited with William P. House and Lawrence Coveney in 1937. This was the first ascent using modern climbing techniques. Wiessner led the entire climb free, placing only a single piece of fixed gear, a piton, which he later regretted, deeming it unnecessary.
