What river forms the eastern border of Nebraska?

The Missouri River forms the eastern border of Nebraska, serving as a natural boundary between Nebraska and the state of Iowa. It plays a significant role in the geography and hydrology of the region, influencing both agricultural practices and the local ecosystem. The Missouri River is also one of the longest rivers in North America and historically has been a vital waterway for trade and transport.

In contrast, the Mississippi River, located further east, does not border Nebraska, while the Amazon and Nile rivers are not located in the United States at all. This highlights the significance of the Missouri River in relation to Nebraska's geography while emphasizing that the other rivers listed have no direct relevance to the state's borders.