Chittenden brought to this enduring work an appreciation of geography and a feeling for the lives and times of colorful trappers and mountain men like Manuel Lisa, William H. Ashley, the Sublette brothers, Jedediah Smith, Jim Bridger, and Kenneth McKenzie. He provided a comprehensive view of the fur trade that still remains sound.

Volume 1 of the Bison edition includes the organization and financing of the fur trade and a detailed history of the major American companies operating in the trans-Mississippi West to the year 1843.