Rocky Mountain Rendezvous: A History of The Fur Trade 1825 - 1840 by Fred R. Gowans is a pretty good read. Almost like a diary of every "organized" rendezvous held during those years.
Forty Years a Fur Trader on the Upper Missouri (Volumes 1 & 2); The Personal Narrative of Charles Larpenteur, 1833-1872 by Charles Larpenteur is a compilation of his journals. Charley was kind of a blowhard and seemed (IMHO) to have a very high regard for himself.
Both are available at Amazon, maybe other places, too. Have fun.
