The Mississippi River Alluvial Plain is an alluvial plain created by the Mississippi River on which lies parts of seven U.S. states, from southern Louisiana to southern Illinois.
The plain is divided into the Mississippi River Delta in the southern half of Louisiana and the inland Mississippi embayment running from central Louisiana to Illinois. The term Mississippi embayment is sometimes used more narrowly to refer to the section on the western side of the river, running through eastern Arkansas, southeastern Missouri, westernmost Tennessee, westernmost Kentucky and southern Illinois, and excluding northwest Mississippi (the alluvial plain known as the Mississippi Delta) on the east bank.
It is the largest ecoregion of Louisiana, covering 12,350 square miles (32,000 km2), and including all of the historic Mississippi River floodplain.
Coordinates: 34°N 91°W / 34°N 91°W