During the 1840s tens of thousands of American migrants made long journeys through the American West seeking land in Oregon, gold in California, and religious liberty in Utah.
The Oregon and California Trails stretched nearly 2,000 miles from jumping-off points near the Missouri River to the Willamette Valley in Oregon and the Sacramento Valley in California; the Mormon Trail 1,300 miles from Nauvoo, Illinois, to Salt Lake City. While dozens of alternate cutoffs were developed to shorten journeys, the course of rivers—the Platte, Sweetwater, Snake, and Humboldt—that provided emigrants and their animals with water dictated the majority of the routes.