Consists of journals, primarily by Clark, which cover the expedition's route up the Missouri River to Fort Mandan in present-day North Dakota and its frigid winter encampment there.
President Thomas Jefferson conceived the Corps of Discovery to travel up the Missouri River to the Rocky Mountains and westward along possible river routes to the Pacific Ocean. Meriwether Lewis and William Clark led the expedition of 1804-6. Along the way they filled hundreds of notebook pages with observations of the geography, Indian tribes, and natural history of the trans-Mississippi West.