Details about the expeditions was provided primarily by Ross, a conscientious chronicler, who recorded Mackenzie's trailblazing expeditions of 1821-23 as well as the difficult 1824 expedition that he led.
"His journals provide the first account there is of daily happenings in the Snake country," historian John Phillip Reid points out. "The most compelling reason Ross and other leaders of the earliest Snake expedition kept journals was to furnish guidance to future trapping parties and inform them of problems, dangers, and places to avoid."
Expeditions in the Snake River Country,
by John Phillip Reid
The Arthur H. Clark Company, 2011
Artwork: Trappers Carrying Furs on Snowshoes
Out of the Past: Snake Country Expedition
History and American West Titles
Outrider Reading Group