Appleman, Roy Edgar. Lewis and Clark: Historic Places Associated with Their Transcontinental Exploration (180406). Washington, D.C.: National Park Service, 1975. Contains many maps and illustrations, some in color.

Bergon, Frank, ed. The Journals of Lewis and Clark. New York: Viking Press, 1989. Selections from the journals, with an introduction by the editor.

Betts, Robert B. In Search of York: The Slave Who Went to the Pacific with Lewis and Clark. Boulder: Colorado Associated Press, 1985. On the important but neglected role (except in myth) of the first African American to cross the country to the Pacific Ocean. Illustrations, some in color.

Clark, Ella E., and Margot Edwards.

Sacagawea of the Lewis and Clark Expedition. Berkeley: University of California Press, 1979. A biography "in historical perspective" of the Indian guide, including her later life until her death in 1884.

DeVoto, Bernard. The Journals of Lewis and Clark. Boston: Houghton Mifflin...