Virginia-born John Colter first answered the call of the West in 1804, when he took off on a journey to the Pacific Ocean and back as part of Lewis and Clark’s famed Corps of Discovery. Two years in the wilderness was more than enough for most of the expedition’s members, but as they made their way home in 1806, Colter decided to shun civilization and strike out on a career as a fur trapper. He soon established himself as one of America’s original mountain men, and may have been the first white man to lay eyes on Yellowstone National Park. A section of Wyoming’s Shoshone River even became known as “Colter’s Hell” for his descriptions of its geothermal activity.

Colter was once wounded while fighting alongside Crow and Flathead tribesmen, but the most legendary chapter in his career came in 1809, when he was captured by a band of Blackfeet while trapping near Three Forks, Montana. After killing his partner, the Indians stripped Colter naked, gave him a brief head start and then chased after him as though he were wild game. Ignoring the rocks and cactus that were shredding his feet, Colter supposedly outran most of the warriors before disarming his closest pursuer and killing him with his own lance. The mountain man then staggered into a fort several days later, having trekked over 200 miles clothed only in a blanket. He would go on to participate in more trapping missions—and have even more run-ins with the Blackfeet—before finally retiring to a Missouri farm in 1810.

In 1822, 18-year-old Jim Bridger joined up with the Rocky Mountain Fur Company on a trapping expedition along the Missouri River. The journey marked the beginning of a 45-year career that saw him discover new routes across the frontier, survive an arrow wound to the back, marry three different Indian wives and found a trading fort on the Oregon Trail. Bridger’s travels took him all the way from the Canadian border to southern Colorado. He made one of the earliest excursions to the Yellowstone region, and famously became the first Anglo-American to see the Great Salt Lake. Upon tasting its briny waters, he incorrectly concluded that it was part of the Pacific Ocean.

After the decline of the fur trade, Bridger reinvented himself as a trader and wilderness guide. He helped blaze Bridger’s Pass and Bridger Trail, both of which were well-traveled by pioneers and gold-seekers, and later worked as a scout for the U.S. Army. Health problems eventually forced “Old Gabe” Bridger to retire in the late-1860s, but by then his frontier exploits and endless supply of tall tales had established him among the greatest of the mountain men. One historian even labeled him a walking “atlas of the West.”

Christopher “Kit” Carson became a folk hero for his depictions in 19th century dime novels and newspapers, but the true story of his career is just as remarkable as the legend. Born in Kentucky in 1809, he fled a saddlemaker’s apprenticeship at age 16 and spent several years working as a fur trapper, teamster and buffalo hunter in the West. Though illiterate and small in stature, Carson was also a natural frontiersman who learned half a dozen native languages and knew the wilderness like the back of his hand.

In 1842, his skills caught the attention of explorer John C. Frémont, who enlisted him as a guide for a mission to map the American West. The pair eventually teamed up on three epic excursions across the Rocky Mountains, California and Oregon, and Carson became a frontier celebrity after Frémont praised him in his expedition dispatches. His fame only grew during the Mexican-American War, when he slipped past enemy lines at the Battle of San Pasquale and made a 30-mile barefoot trek to San Diego to fetch reinforcements.

Jedidiah Smith developed his thirst for adventure by reading the journals of Lewis and Clark as a boy, and he later followed in their footsteps during a legendary career as a trapper and explorer. The New Yorker was one of several future mountain men who answered William Ashley’s 1822 call for “enterprising young men” to trap beaver and otter in the uncharted frontier. Tasked with scouting out new hunting grounds in the Dakotas and Wyoming, he helped lead an expedition that rediscovered South Pass, a key Rocky Mountain crossing that became part of the Oregon Trail. Smith went on to explore huge swaths of the West as the owner of his own fur trading company. He traversed the Mojave Desert into Southern California in 1826, and later became the first explorer to journey the Pacific coastline from California into Oregon.

As with many mountain men, Smith’s travels were often punctuated by episodes of violence. His scouting parties were ambushed and decimated by Indian attacks on multiple occasions, and he famously had his ribs smashed and his scalp partially torn off in a grizzly bear mauling. He wore his hair long for the rest of his life to cover the scars. Smith tried to retire from the hazards of the wilderness in 1830, but just a year later he was attacked and killed by Comanche Indians while traveling the Santa Fe Trail. At the time of his death, the great explorer was just 32 years old.

The son of a black woman and a white man, James Beckwourth was born a slave on a Virginia plantation before being taken to Missouri as a boy. After receiving his freedom in the 1820s, he signed on with a fur trapping expedition and headed west to the Rocky Mountains in search of adventure. The details of Beckwourth’s time in the wilderness are hazy—he was a notorious teller of tall tales who once claimed to have escaped an Indian attack by sprinting 95 miles in a single day—but he seems to have worked as a mountain man and free trapper before dropping out of society and joining a band of Crow Indians in the late-1820s. He eventually spent at least six years living among the tribe, learning their language and marrying as many as ten different native women. Beckwourth even claimed that he became a powerful war chief and fought in several battles against the Blackfeet.

After leaving the Crow in the mid-1830s, Beckwourth worked as everything from a courier in Florida’s Seminole Wars to an innkeeper, trader and gambler, but he was best known as a scout and wilderness guide. He helped found a trading post that grew into the modern town of Pueblo, Colorado, and in 1850 he discovered a new route through the Sierra Nevada Mountains. The crossing, known as Beckwourth Pass, later became a popular route for prospectors headed to the gold fields of California.

Like Jedidiah Smith, Tennessee native Joseph Walker was a born explorer who pursued fur trapping and scouting as a way of financing his wanderlust. He first ventured west in 1820 as part of an illegal trapping expedition to Spanish-controlled New Mexico territory, and later served as a guide for the likes of Benjamin Bonneville and John C. Frémont. While working for Bonneville in 1833, Walker led an expedition that bushwhacked its way from Wyoming to California across the Sierra Nevada. His party was forced to eat their horses just to survive, but after exiting the mountains they became the first white men to encounter giant sequoia trees and the wonders of the Yosemite Valley. It was a sight Walker would never forget. He even had the words “Camped at Yosemite” inscribed on his tombstone.

Walker later worked as trapper, scout, wagon train guide and ranch owner, but he continued to explore the blank spots on the map at every opportunity. In 1861, at the age of 62, he set off on a two-year prospecting expedition across New Mexico, Arizona and Colorado. By the time his failing eyesight forced him to retire in 1867, he had spent some five decades on the frontier and served as a guide for hundreds of soldiers and pilgrims. Amazingly, during all of Walker’s years blazing new trails and traveling through hazardous territory, only one man is reported to have died under his command.