Before the late 18th century when French trappers and Spaniards stepped in, the Rocky Mountain area was a land of many tribes, including the Nez Percé, the Shoshone, the Crow, the Lakota and the Utes.
Meriwether Lewis and William Clark claimed their enduring fame after the USA bought almost all of present-day Montana, Wyoming and eastern Colorado in the Louisiana Purchase in 1803. The two explorers set out to survey the land, covering 8000 miles in three years. Their success urged on other adventurers, and soon the migration was in motion. Wagon trains voyaged to the mountainous lands into the 20th century, only temporarily slowed by the completion of the Transcontinental Railroad across southern Wyoming in the late 1860s.
To accommodate settlers, the USA purged the western frontier of the Spanish, British and, in a truly shameful era, most of the Native American population. The government signed endless treaties to defuse Native American objections to increasing settlement, but always reneged and shunted tribes onto smaller reservations. Gold miners’ incursions into Native American territory in Montana and the building of US Army forts along the Bozeman Trail ignited a series of wars with the Lakota, Cheyenne, Arapaho and others.
Gold and silver mania preceded Colorado’s entry to statehood in 1876. Statehood soon followed for Montana (1889), Wyoming (1890) and Idaho (1890). Along with miners, white farmers and ranchers were the people with power in the late 19th century.
Mining, grazing and timber played major roles in the area’s economic development, sparking the growth of cities and towns to provide financial and industrial support. They also subjected the region to boom-and-bust cycles by unsustainable use of resources and left a legacy of environmental disruption.
After the economy boomed post-WWII, the national parks started attracting vacationers. Tourism is now a leading industry in all four states, with the military – there is a major presence in Colorado especially – trailing not far behind.