The Platte River // (Pawnee: Kíckatusʾ) is a major river in the state of Nebraska and is about 310 mi (500 km) long. Measured to its farthest source via its tributary the North Platte River, it flows for over 1,050 miles (1,690 km). The Platte River is a tributary of the Missouri River, which in turn is a tributary of the Mississippi River which flows to the Gulf of Mexico. The Platte over most of its length is a muddy, broad, shallow, meandering stream with a swampy bottom and many islands—a braided stream. These characteristics made it too difficult for canoe travel, and it was never used as a major transportation route by European-American trappers or explorers.
The Platte is one of the most significant tributary systems in the watershed of the Missouri, draining a large portion of the central Great Plains in Nebraska and the eastern Rocky Mountains in Colorado and Wyoming. The river valley played an important role in the westward expansion of the United States, providing the route for several major emigrant trails, including the Oregon, California, Mormon and Bozeman trails. The first Europeans to see the Platte were French explorers and fur trappers about 1714; they first called it the Nebraskier (Nebraska), a transliteration of the name given by the Otoe people, meaning "flat water".