Three Major Rivers of the Central United States

1. Mississippi River: North America's longest river (~2,340 mi), drains 31 U.S. states and 2 Canadian provinces.
2. Missouri River: Mississippi's longest tributary (~2,341 mi), originates in Montana Rockies, joins Mississippi at St. Louis.
3. Ohio River: Largest tributary by volume, formed at Pittsburgh by Allegheny + Monongahela, joins Mississippi at Cairo, IL.

Together, these rivers form the backbone of the central U.S. drainage basin, supporting commerce, agriculture, and ecosystems across the heartland.