Since 1841, Nebraska's Platte River Valley has served as a historic highway of westward migration. In this area, the Overland Trail divided into two branches, one following the north fork of the river and the other the south fork. Emigrants bound for Oregon or California crossed the South Platte near here and traveled up the North Platte Valley past landmarks such as Chimney Rock and Scott's Bluffs. After gold was discovered in the Rocky Mountains in 1859, growing numbers of travelers followed the South Fork of the Platte to Denver and the mining camps. Although the South Platte could be forded at several points, the crossing most often used was the Old California Crossing, several miles east of present Big Springs. Whatever crossing they chose, emigrants and their heavily loaded wagons faced a formidable obstacle in the river's wide, sandy channel. Today, the Platte Valley remains an important thoroughfare across Nebraska and the nation, and a few miles east I-80 divides into two major routes, echoing the South Platte region's nineteenth-century role as a junction for overland travel.