JJD RSBUD-35 Christopher "Kit" Carson, Army Frontier Scouts

A mountain man was an explorer who lived in the wilderness. 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.

Mountain men were most common in the North American Rocky Mountains from about 1810 through to the 1880s (with a peak population in the early 1840s). Approximately 3,000 mountain men ranged the mountains between 1820 and 1840, the peak beaver-harvesting period. While there were many free trappers, most mountain men were employed by major fur companies. The life of a company man was almost militarized. The men had mess groups, hunted and trapped in brigades and always reported to the head of the trapping party. This man was called a "boosway", a bastardization of the French term bourgeois. He was the leader of the brigade and the head trader.