Upper Mississippi River Basin
The Mississippi River is the state boundary between Missouri and Illinois along 361 miles of the Upper Mississippi River. For 126 miles the Lower Mississippi River separates Missouri from Kentucky and Tennessee. The Mississippi River is an important waterway, transporting goods to both domestic and foreign markets. Upstream of St. Louis, a series of locks and dams maintain adequate water depths for navigation. Downstream of St. Louis, the Mississippi River is free flowing all the way to the Gulf of Mexico. The Mississippi River also provides an important source of water for drinking, cooling, recreation, and fish and wildlife.

The Ohio River confluence is a dividing line within the Mississippi River basin. The Upper Mississippi River basin encompasses the headwaters in Minnesota and Wisconsin to the confluence near Cairo, Illinois. The Lower Mississippi River basin includes the area below the confluence to the Gulf of Mexico.


Lower Mississippi River Basin

River Data

Associations and Groups

Projects and Studies

Mississippi River