A prominent geographical feature of the continental United States, a significant waterway serves as a border for several states. This major river system is readily identifiable on any map depicting the United States. Its location is primarily in the eastern Midwest region.
Historically, this river served as a vital transportation route, facilitating trade and westward expansion. Its presence influenced settlement patterns and continues to support economic activity through navigation and resource provision. The river also marks a climatic and ecological transition zone.