Platte River, a river in Nebraska. It begins in west-central Nebraska at the junction of the North and South Platte rivers, whose sources are in the Rocky Mountains. The Platte follows a curving 310-mile (499-km) course eastward across the state and joins the Missouri River near Omaha. Chief tributaries are the Loup and Elkhorn rivers.
During the 19th century, the Platte River valley was an important route in the westward expansion of the United States. Through the valley passed the Mormon and Oregon trails and the Overland Stage Route.
