I concur.  This book lists descriptions of some trips on rivers such as the Laird, via the Grand Canyon of the Laird, and also the route up and over MacDougall Pass (the lowest elevation pas of the Rocky Mountains, way up north of the Arctic circle), as well as some descriptions of what the conditions of the first expeditions were like.  I think it would tie in with Arthur Rays two works, "Indians in the Fur Trade," "The Canadian Fur Trade In The Industrial Age," and Eric Morse's work, "Fur Trade Canoe Routes of Canada: Then and Now."  

P.  S.  Should anyone here attempt to read A.  Ray, be prepared to do some serious and intense reading - he certainly wrote with the academic scholars in mind, not the popular readers.  Morse and Karamanski are definitly easier to digest and comprehend.