Mississippi River Tributaries: Not Rivers *In* It, But Rivers *Feeding* It

Clarification: No Rivers Inside a River

The Mississippi River receives water from major tributaries—it doesn't contain other rivers internally.

Largest Tributaries (by discharge)

1. Ohio River: 281,000 cfs avg; joins at Cairo, IL – largest by volume
2. Missouri River: 76,000 cfs; joins near St. Louis – longest tributary (2,341 mi)
3. Arkansas River: 41,000 cfs; joins in AR – 1,469 mi
4. Red River: 31,000 cfs; joins in LA – southernmost major tributary
5. Tennessee River: Via Ohio; 68,000 cfs – TVA system

System Scale

• Mississippi Basin: 1.2M mi² (41% of lower 48)
• 250+ tributaries >100 mi long
• Drains 32 US states + 2 Canadian provinces

The Ohio contributes more water than the Upper Mississippi itself at their confluence—making the "Mississippi" below Cairo hydrologically more "Ohio" than Mississippi.