The Bear River Divide in southwestern Wyoming has been the locus of Euro-American interests since the 1820' s. Mountain men knew the area as one rich in beaver, whose pelts supported the colorful Rendezvous Era of 1820-40. Indeed place names such as Bridger Butte and the Smith's Fork are derived from these early trappers. The mountain men blazed the trail for the great Westward Expansion and immigrants followed routes through the Bear River Divide first identified by trappers such as Jim Bridger decades earlier. American settlement began in the 1880's as ranching operations became established on the flanks of the Bear River Divide. Coal was discovered in the region around the turn of the century and supported towns such as Kemmerer and Cumberland. Petroleum exploration soon followed, and with plentiful supplies of coal, oil, and gas, the Bear River Divide provided a livelihood for the region's inhabitants that endures today.