Atchafalaya Basin

The Atchafalaya Basin, or Atchafalaya Swamp, is the largest swamp in the United States. Located in south central Louisiana, it is a combination of wetlands and river delta area where the Atchafalaya River and the Gulf of Mexico converge. The river stretches from near Simmesport in the north through parts of eight parishes to the Morgan City area in the south. The Atchafalaya is unique among Louisiana basins because it has a growing delta system (see illustration) with nearly stable wetlands.