The route started at St. Joseph, Missouri on the Missouri River, it then followed what is modern-day U. S. Highway 36 (US 36 the Pony Express Highway) to Marysville, Kansas, where it turned northwest following Little Blue River to Fort Kearny in Nebraska. Through Nebraska it followed the Great Platte River Road, cutting through Gothenburg, Nebraska, clipping the edge of Colorado at Julesburg, Colorado, and passing Courthouse Rock, Chimney Rock, and Scotts Bluff, before arriving at Fort Laramie in Wyoming. From there it followed the Sweetwater River, passing Independence Rock, Devil's Gate, and Split Rock, to Fort Caspar, through South Pass to Fort Bridger and then down to Salt Lake City. From Salt Lake City it generally followed the Central Nevada Route blazed by Captain James H. Simpson of the Corps of Topographical Engineers in 1859. This route roughly follows today's US 50 across Nevada and Utah. It crossed the Great Basin, the Utah-Nevada Desert, and the Sierra Nevada near Lake Tahoe before arriving in Sacramento. Mail was then sent via steamer down the Sacramento River to San Francisco. On a few instances when the steamer was missed, riders took the mail via horseback to Oakland, California.