The Atchafalaya Basin

The Atchafalaya Basin is the nation's largest river swamp, containing almost one million acres of America's most significant bottomland hardwoods, swamps, bayous and backwater lakes. The basin begins near Simmesport, La., and stretches 140 miles southward to the Gulf of Mexico. Currently, the Atchafalaya Basin is bound by natural ridges formed by levee building along active and abandoned courses of the Mississippi River.

Learn more about the Basin from those who grew up in it on our Mapping the Basin ArcGIS storymap, created by Jason Theriot in partnership with The T.E.C.H.E. project.

Mapping the Basin

More interesting facts about the Atchafalaya Basin:

• It is larger than the Florida Everglades
• It’s five times more productive than any other river basin in North America
• About 65 species of reptiles and amphibians inhabit the Basin
• Over 250 known species of birds fly in the Basin
• Other species of animals found in the area include black bear, nutria, fox, muskrat, beaver, otter and raccoon
• The Basin is home to the largest nesting concentration of bald eagles in the south central United States
• There are more than 100 different species of fish and aquatic life in the Basin
• The Basin has an estimated average annual commercial harvest of nearly 22 million pounds of crawfish
• The Basin contains the largest contiguous bottomland hardwood forest in North America and is the largest overflow alluvial hardwood swamp in the United States

Over the past 10,000 years or more, the Mississippi River has changed its path several times, ranging from the current location of Bayou Teche to today’s route past Baton Rouge and New Orleans. The Atchafalaya River runs down the middle of that traditional Mississippi floodplain and would probably be the main channel of the Mississippi by now, if not for the Old River Control Structure[s] near Simmesport.

Formerly the lower section of the Red River, the Atchafalaya River became much smaller after the Red joined the Mississippi in the 15th century. By the 19th century, the Atchafalaya was blocked by a huge log raft, as were parts of the Red.

Additional Information Sources

• For information on Corps of Engineers activities in the ABFS, go to http://www.mvn.usace.army.mil.
• For information on Louisiana State water management in the ABFS, go to http://www.dnr.state.la.us/Atchafalaya.