John Colter, a Virginia backwoodsman, like many of his contemporaries in 1803, was driven by the fever to drive Westward. It was that urge which led him to the town of Maysville where he became a member of the Lewis and Clark expedition. Primarily a trapper, Colter spanned the vast uncharted territory of the West--the Wind River Mountains and Teton Range--on foot, with the certainty of a fearless animal. His achievement in being the first man to explore the Yellowstone territory and the contribution he made toward the charting of this area are vigorously recounted in this biography.