born 1775, in or near Staunton, Va. died 1813, in present-day Missouri, U.S. U.S. explorer. A member of the Lewis and Clark Expedition (1803-06), in 1807 he was sent to make contact with Indian tribes in the Yellowstone River area; he became the first white man to see and describe the region. In three expeditions to the head of the Missouri River (1808-10), he narrowly escaped death in battles with Indians. He retired to a farm on the Missouri