Wheeler, O. D. 1. (1904). The trail of Lewis and Clark, 1804-1904: A story of the great exploration across the continent in 1804-6; with a description of the old trail, based upon actual travel over it, and of the changes found a century later. New York ; London: G.P. Putnam's Sons.

Wheeler, Olin D. 1852-1925. The Trail of Lewis and Clark, 1804-1904: A Story of the Great Exploration Across the Continent in 1804-6; With a Description of the Old Trail, Based Upon Actual Travel Over It, and of the Changes Found a Century Later. New York ; London: G.P. Putnam's Sons, 1904.

Wheeler, Olin D. 1852-1925. The Trail of Lewis and Clark, 1804-1904: A Story of the Great Exploration Across the Continent in 1804-6; With a Description of the Old Trail, Based Upon Actual Travel Over It, and of the Changes Found a Century Later. New York ; London: G.P. Putnam's Sons, 1904.