As the 1840s approached, the fur trade began to collapse. There was a lessening demand for furs in Europe. Fur bearing animals had become over-trapped and there were no longer many to be found. With the silk trade, fabric took a stronghold and furs were considered too expensive for the common person to wear. At the same time, killing an animal for fur became less politically correct.
Mountain Man, Robert Newell, told Jim Bridger: “We are done with this life in the mountains — done with wading in beaver dams, and freezing or starving alternately — done with Indian trading and Indian fighting. The fur trade is dead in the Rocky Mountains, and it is no place for us now, if ever it was.”
The final rendezvous was held in 1840.
As trapping became less and less lucrative, other means of earning a livelihood began a whisper in the ear of the weary mountain man.Fortuitously, Manifest Destiny received a powerful push with two new international treaties in early 1846 and early 1848 officially settling ownership of the Pacific coast territories and Oregon Country to the United States. This spurred an upsurge in America’s ongoing migration, in 1847-48, as it built rapidly from a trickle to a flood, largely due to the highly organized Mormon migration that exploited the road to the Great Salt Lake discovered by Mountain Man Jim Bridger.The migration further exploded in 1849 as “The Forty-Niners,” responded to the discovery of gold in California in 1848.
Many of the mountain men settled into jobs as Army Scouts, wagon train guides and settlers along the reliable mule trails through the lands which they had helped open up. The trails gradually improved into wagon capable freight roads.
Others, like William Sublette, opened up fort-trading posts along the Oregon Trail to service the remnant fur trade and the settlers heading west. During the summer of 1845 alone an estimated 5,000 immigrants went west. These immigrant trains from the east, and government surveying expeditions, provided a new realm of employment for the trappers.Military service was often the natural progression for trappers who guided for surveying expeditions. Sometimes the trappers joined the service out of loyalty to a particular officer, or because they were in the right place at the right time. Actual titles were not often needed and sometimes only given after long service.