Colter's Hell

Colter's Hell is an area of fumaroles and hot springs on the Shoshone River near Cody in the U.S. state of Wyoming. The thermal area covers about a square mile at the mouth of the Shoshone's canyon. Its thermal activity has declined ever since its description by mountain man John Colter, who passed through the region in the winter of 1807-1808. Colter's account of the features on what was then called the Stinkingwater River has subsequently been confused with the much more extensive and powerful geysers in Yellowstone National Park, which Colter may not have actually visited.

• http://en.wikipedia.org/wiki/Colter's Hell