Just two historical corrections to your otherwise excellent review:

Paragraph 1: The western fur trade didn’t peak in the 1820s, but rather the mid-1830s. When Glass went out with Henry in 1822 the Western fur trade had already begun 15 years earlier. The Rocky Mountain Fur Company, established by Ashley and Henry in 1822, continued until 1834. The American Fur Company, established in 1808, continued until 1843.

Paragraph 6: I would disagree in calling the French "voyageurs". Nothing in what they do would class them with voyageurs, as voyageurs were watermen, engaged by a company to transport goods to an outpost and furs back to the home base.