The expedition was financed by John Jacob Astor, a rival of the Hudson’s Bay Company. However, that changed in 1832 when Benjamin Bonneville, a United States Army officer, requested a leave of absence to pursue an expedition to the West. The trail passes through Missouri, Kansas, Nebraska, Colorado, Wyoming, Idaho, Utah, Nevada, Oregon, and California.īefore the trail was blazed, the Great Basin region had only been partially explored during the days of Spanish and Mexican rule. The specific route that emigrants and forty-niners used depended on their starting point in Missouri, their final destination in California, their wagons and livestock conditions, and yearly changes in water and forage along the different routes. The general route began at various jumping-off points along the Missouri River and stretched to various points in California, Oregon, and the Sierra Nevada.

The California Trail carried over 250,000 gold-seekers and farmers to the goldfields and rich farmlands of the Golden State during the 1840s and 1850s, the greatest mass migration in American history.