By the golden age of the mountain man in the mid-19th-century, there were perhaps only three thousand living in the West. Their origins were disparate, although they included many Anglo-Americans. A good number hailed from wilderness regions of Kentucky and Virginia and throughout the newly purchased Louisiana Territory, which occupied the entire central section of the continent.

French Canadians traveled from the north to work in the fur trade, while Creole-Europeans represented approximately 15 percent of the men known to be living the isolated mountain life. Others were of Métis, Spanish, American, Black, Indian, and mixed-blood origin, most often Iroquois or Delaware. Most came to the West in their late adolescent years, the oldest learning the trade in their 30s. Many roamed the west for as long as their constitutions would hold up under constant attacks on their health and personal safety. Some stayed too long and failed to survive the experience. Among the most famous, Jim Bridger arrived at the age of 16, while Edward Robinson was eventually killed in his 60s by what were known as “bad snakes,” a reference to the Snake tribe in Idaho country. Jim Beckwourth left the mountains at 68 and Old Bill Williams died at the age of 62 when a band of Utes “made him to come.”

During the mid-19th century, the mountain man persona transformed into that of a more multifaceted individual. Frontiersmen who were once alone in the West were hired on as guides and scouts for the military, or for settlement caravans crossing the new trails to the Pacific Northwest and California. A third generation of mountain men followed the Civil War as veterans headed west to test their survival skills learned in the military.

The search for opportunities near the Pacific was not merely an option exercised by unemployed soldiers who could find no other use for themselves, as many had no home to which they could return. Meanwhile, the opportunities widened for prospectors, hunters, merchants, farmers, ranchers, and lawmen, occupations not yet in existence for the prior generation.