William Clark kept this diary on an expedition to make a treaty with the Osage Indians in the Missouri Territory. A sketch drawn under the September 16 entry is apparently a draft of Clark's Fort Osage map, while the first page of notes presents color scheme used on another draft. See Kate L. Gregg, Westward with Dragoons (1937: 48) for the map in printed version.

Kept during the Lewis and Clark Expedition, this diary notes distances covered and a draft of suggestions for routes for the fur trade.