While most Oregon-bound emigrants traveled a route that passed by landmarks in Missouri, Kansas, Nebraska, Wyoming, Idaho and Oregon, there was never just one set of wagon ruts leading west. Pioneers often spread out for several miles across the plains to hunt, find grazing patches for their animals and avoid the choking dust clouds kicked up by other wagon trains. As the years passed, enterprising settlers also blazed dozens of new trails, or cutoffs, that allowed travelers to bypass stopping points and reach their destination quicker. These shortcuts were especially popular in Wyoming, where the network of alternative pathways meandered more than a hundred miles north and south.

Frontier explorers and fur trappers blazed the rough outlines of the Oregon Trail in the early 19th century, but the route was initially considered too demanding for women, children or covered wagons to navigate. That changed in 1836, when newlywed missionaries Marcus and Narcissa Whitman took a small party of wagons from St. Louis to the Walla Walla Valley to minister to Cayuse Indians. 28-year-old Narcissa became the first white woman to traverse the Rocky Mountains, and her colorful letters home were later published in Eastern newspapers, convincing many would-be pioneers that it was possible for their families to survive the journey west. Still, it wasn’t until 1843 that the pioneer dam finally burst. That year, Marcus helped lead the first major wagon train of around 1,000 settlers along the Oregon Trail, an exodus now known as the “Great Migration.” Traffic soon skyrocketed, and by the late-1840s and early 1850s, upwards of 50,000 people were using the trail each year.

Popular depictions of the Oregon Trail often include trains of boat-shaped Conestoga wagons bouncing along the prairie. But while the Conestoga was an indispensable part of trade and travel in the East, it was far too large and unwieldy to survive the rugged terrain of the frontier. Most pioneers instead tackled the trail in more diminutive wagons that become known as “prairie schooners” for the way their canvas covers resembled a ship’s sail. These vehicles typically included a wooden bed about four feet wide and ten feet long. When pulled by teams of oxen or mules, they could creak their way toward Oregon Country at a pace of around 15 to 20 miles a day. They could even be caulked with tar and floated across un-fordable rivers and streams. Prairie schooners were capable of carrying over a ton of cargo and passengers, but their small beds and lack of a suspension made for a notoriously bumpy ride. With this in mind, settlers typically preferred to ride horses or walk alongside their wagons on foot.

As traffic on the Oregon Trail increased, a bustling industry of frontier trading posts sprang up to supply food and equipment for the five-month haul. In popular jumping-off points like Independence, Missouri, unscrupulous merchants made a killing by conning frightened pioneer families into buying more provisions than they actually needed. The overloading meant that many sections of trail became junk heaps filled with discarded food barrels and wagon parts. Broken down prairie schooners and dead draft animals also littered the roads, and it wasn’t unusual to see personal items like books, clothes and even furniture. Fort Laramie in Wyoming eventually became known as “Camp Sacrifice” for its reputation as an Oregon Trail dumping ground. During the Gold Rush of 1849, pioneers reportedly abandoned a whopping 20,000 pounds of bacon outside its walls.

Contrary to the depictions of dime novels and Hollywood Westerns, attacks by the Plains Indians were not the greatest hazard faced by westbound settlers. While pioneer trains did circle their wagons at night, it was mostly to keep their draft animals from wandering off, not protect against an ambush. Indians were more likely to be allies and trading partners than adversaries, and many early wagon trains made use of Pawnee and Shoshone trail guides. Hostile encounters increased in the years after the beginning of the Civil War, but statistics show only around 400 settlers were killed by natives between 1840 and 1860. The more pressing threats were cholera and other diseases, which were responsible for the vast majority of the estimated 20,000 deaths that occurred along the Oregon Trail.

Along with painting messages and mottos on their wagon canvasses, pioneers also developed a tradition of carving their names, hometowns and dates of passage on some of the stone landmarks they encountered during their journey west. One of the most notable prairie guest books was Independence Rock, a 128-foot-tall granite outcropping in Wyoming dubbed “The Register of the Desert.” Thousands of travelers left their mark on the rock while camping along the nearby Sweetwater River. Those in a hurry sometimes even paid stonecutters a few dollars to carve their messages for them. In addition to Independence Rock, pioneers also left behind signatures on Register Cliff and Names Hill, two other sites in Wyoming.

Only around 80,000 of the estimated 400,000 Oregon Trail emigrants actually ended their journey in Oregon’s Willamette Valley. Of the rest, the vast majority splintered off from the main route in either Wyoming or Idaho and took separate trails leading to California and Utah. The California Trail was eventually traveled by some 250,000 settlers, most of them prospectors seeking to strike it rich in the gold fields. The Utah route, meanwhile, shuttled roughly 70,000 Mormon pilgrims to the lands surrounding Salt Lake City.

One trip on the Oregon Trail was more than enough for most pioneers, but Ohio native Ezra Meeker eventually made the trek a half-dozen times using nearly every available means of conveyance. The unusual odyssey began in 1906, when the 76-year-old jumped behind the reins of a covered wagon and retraced the steps of his original pioneer journey from 54 years before. Meeker was concerned that the legacy of the Oregon Trail was being forgotten, so he made frequent stops to give lectures on its history and install homemade “Meeker Markers” at pioneer landmarks. The trip made him a national celebrity. Crowds gathered to mark his arrival in major cities, and he eventually piloted his wagon all the way to Washington, D.C. for a meeting with President Theodore Roosevelt. Meeker went on to journey the Oregon Trail several more times by wagon, train and automobile. His final crossing came at age 94, when he made the trip in a biplane flown by famed pilot Oakley Kelly.

By the time the last wagon trains crossed in the 1880s, mass migration on the Oregon Trail had left an indelible mark on the American frontier. Decades of prairie schooner traffic carved up certain sections of the trail, leaving imprints in stone and wearing down grasslands so much that nothing grows on them to this day. These pioneer wagon ruts can still be seen in all six of the states that once encompassed the trail.