John Colter was a crack hunter with the Lewis and Clark expedition before striking out on his own as a mountain man and fur trader. A solitary journey in the winter of 1807-8 took him into present-day Wyoming. To unbelieving trappers he later reported sights that inspired the name of Colter's Hell. It was a sulfurous place of hidden fires, smoking pits, and shooting water. And it was real. John Colter is known to history as probably the first white...