Chapter 5 was written by Major Long, and points out significant hydrographical and topographical features of the country the expedition traversed. Long also evaluates Native Americans' complex relations with the United States and its settlers. The book includes several appendices on natural history. Thomas Say classifies zoological materials and observations, and Lewis de Schweinitz contributes a catalogue of the plant specimens Say collected along the way. James Colhoun presents astronomical data, and Joseph Lovell, the U.S. Surgeon-General, compares climate readings at several American military outposts. The volume concludes with a comparative list of Native American vocabularies.

Journey from Philadelphia, to Lake Winnipeg, and back across the lake country and the northern boundary of the Great Lakes. The route traces the Mississippi River, Minnesota River, and Red River.