On my many trips between Missouri and Colorado, I often think of the emigrants who crossed the Great Plains via wagon trains. Of course, they were preceded by explorers and trappers on horseback who scoured the West during the 17th and 18th Centuries and by the Lewis & Clark Expedition that followed the Missouri and Columbia River Valleys from 1803-1805. Like the latter expedition, most of the early emigrants began their journeys in what is now the State of Missouri.
Within a decade of Lewis and Clark, emigrants were following the Santa Fe Trail, which began in Franklin, on the north bank of the Missouri River (not far west of Columbia); this was the farthest upstream that steamboats could reach at the time. The wagon trail crossed the river at Arrow Rock, passed through Lexington and continued on to Independence; within a few years, this latter city became the primary steamboat destination. Leading west to Olathe, the Santa Fe Trail angled WSW through what is now Kansas, passing through Great Bend and Dodge City en route; just beyond Garden City, it split into its Mountain and Cimarron Forks, the former cutting through southern Colorado to Bent's Fort and the latter crossing northwest Oklahoma and northeast New Mexico on their way to Santa Fe.
The Oregon, California and Mormon Trails began at Independence, Missouri, splitting from the Santa Fe Trail in eastern Kansas, southeast of Lawrence. They then followed a common path northwestward (crossing the Kansas River at Topeka) and entered Nebraska, continuing westward along the Platte, North Platte, Sweetwater and Snake Rivers, thereby skirting the high ranges of Colorado and Wyoming. At Fort Hall, in southeastern Idaho, these three trails split, heading toward Oregon, California and Utah. By the late 1860s, railroads crossed the Great Plains and Intermountain West, putting an end to the wagon train era.