After the completion of the Lewis and Clark expedition, William Clark conducted a diplomatic expedition into the Missouri Territory where he would later serve as governor and superintendent of Indian affairs at St. Louis. His 1808 diary (8/25-9/22) recounts his journey to form a treaty with the territory's Osage Indians. In addition to detailed accounts of daily events, including interactions with indigenous peoples, this volume features a sketch that may have served as the basis of Clark's Fort Osage map (9/16/1808). Researchers interested in the early national period, U.S. midwestern exploration, and native diplomacy ought to find the journal particularly compelling.