Mississippi Alluvial Plain (ecoregion)

Ecoregion in the southern United States Mississippi Alluvial Plain ecoregionMississippi Alluvial PlainEcologyBorders List Interior River Valleys and Hills (72)Mississippi Valley Loess Plains (74)Southern Coastal Plain (75)Gulf of MexicoWestern Gulf Coastal Plain (34)South Central Plains (35)Ouachita Mountains (36)Arkansas Valley (37)Boston Mountains (38)Ozark Highlands (39) GeographyArea44,834 km2 (17,311 mi2)CountryUnited StatesStatesArkansasIllinoisKentuckyLouisianaMississippiMissouriTennesseeClimate typeHumid subtropical (Cfa) The Mississippi Alluvial Plain is a Level III ecoregion designated by the Environmental Protection Agency (EPA) in seven U.S. states, though predominantly in Arkansas, Louisiana, and Mississippi. It parallels the Mississippi River from the Midwestern United States to the Gulf of Mexico. The Mississippi Alluvial Plain ecoregion has been subdivided into fifteen Level IV ecoregions. Description The Mississippi Alluvial Plain extends along the Mississippi River from the confluence of the Ohio River and Mississippi River southward to the Gulf of Mexico; temperatures and annual average precipitation increase toward the south. It is a broad, nearly level, agricul