Mountain men were trappers and explorers who roamed the North American Rocky Mountains — from about 1810 through the 1880s (with a peak population in the early 1840s) where they were instrumental in opening up the various Emigrant Trails (widened into wagon roads) allowing Americans in the east to settle the new territories of the far west by organized wagon trains traveling over roads explored and in many cases, physically improved by the mountain men and the big fur companies originally to serve the mule train based inland fur trade.

They arose in a natural geographic and economic expansion driven by the lucrative earnings available in the North American fur trade, in the wake of the various 1806–07 published accounts of the Lewis and Clark expeditions’ (1803–1806) findings about the Rockies and the (ownership disputed) Oregon Country where they flourished economically for over three decades.

By the time the two new international treaties in early 1846 and early 1848 respectively[1] settled new western coastal territories officially on the United States and spurred a large upsurge in migration, the days of many Mountain men making a good living by fur trapping had become a thing of the past as the industry was a failing subsistence because of over trapping activity vice the lucrative boom business it once been. Fortuitously, America’s ongoing western migration by wagon train with the goal of claiming cheap lands in the west was however building rapidly from a trickle of settlers from 1841’s opening of the Oregon Trail (now a wagon road) to a flood of emigrants headed west by 1847–49 and thereafter well into the later 1880s.

With the silk trade and over trapped (scarcity driven) quick collapse of the North American beaver based fur trade in the later 1830s–1840s, many of the mountain men settled into jobs as Army Scouts, wagon train guides and settlers in and through the lands which they had helped open up. Others, like William Sublette opened up fort-trading posts along the Oregon Trail to service the remnant fur trade and the settlers heading west.

Mountain men were ethnically, socially, and religiously diverse, fitting no ready stereotype, and while they considered themselves independent, were in fact, economically an arm of the big fur companies which held annual fairs for the mountain men to sell their wares known as Trapper’s rendezvous. Most were born in Canada, the United States, or in Spanish-governed Mexican territories, although some European immigrants also moved west in search of financial opportunity, and the French and British both had long standing active fur trading industries in Canada. Like any businessman, Mountain men were primarily motivated by profit, trading Amerindians (and sometimes trapping) for beaver and other skins and selling the skins, although some few were more interested in exploring the West and traded solely to support their passion. As such, most of them were part trader, part explorer, part exploiter, part trappers, part teamsters, and part settlers, sometimes farmers or occasional (army) hired scouts; most survived and kept their scalps by having good relations with one or more native tribes, being multilingual out of necessity, and quite frequently living part of the year (mainly winters) with Amerindians and as often, taking Indian wives in the normal course of human events. By the time the fur trade began to collapse in the 1840s providing motivation to change jobs, the trails they had explored and turned into reliable mule trails and improved gradually into wagon capable freight roads combined to allow them to hire themselves as guides and scouts, just as the great push west along the newly opened Oregon Trail built up from a trickle of settlers in 1841 to a steady stream in 1844–1846, and then became a flood as the highly organized Mormon migration exploited the road to the Great Salt Lake discovered by mountain man Jim Bridger in 1847–1848. The migration would explode in 1849’s “The Forty-Niners” in response to the discovery of gold in California in 1848. Manifest Destiny had received a powerful push in the spring and summer of 1846 with the international treaties settling the ownership of the Pacific coast territories and the Oregon Country on the United States.