Atchafalaya Basin

The Atchafalaya Basin, or Atchafalaya Swamp, is the largest wetland and 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 southern area.The Atchafalaya is different among Louisiana basins because it has a growing delta system (see illustration) with wetlands that are almost stable. The basin contains about 70% forest habitat and about 30% marsh and open water. It contains the largest contiguous block of forested wetlands remaining (about 35%) in the lower Mississippi River valley and the largest block of floodplain forest in the United States. Best known for its iconic cypress-tupelo swamps, at 260,000acre, this block of forest represents the largest remaining contiguous tract of coastal cypress in the US.Geographical featuresThe Atchafalaya Basin and the surrounding plain of the Atchafalaya River is filled with bayous, bald cypress swamps, and marshes which gives way to brackish estuarine conditions and ends in the Spartina grass marshes where the Atchafalaya River meets the Gulf of Mexico. It includes the Lower Atchafalaya River, Wax Lake Outlet, Atchafalaya Bay, and the Atchafalaya River and Bayous Chene, Boeuf, and Black navigation channel. See maps and photo views of the Atchafalaya Deltas centered on.