The Atchafalaya Basin or Atchafalaya Swamp

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 Atchafalaya is unique among basins because it has a growing delta system with nearly stable wetlands.

The Atchafalaya Basin, the surrounding plain of the river, is filled with bayous, bald cypress swamps, and marshes that give way to more brackish conditions and end in the Spartina grass marshes, near and at where it 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.

The basin, which is susceptible to heavy flooding, is sparsely inhabited. The basin is about 20 miles (32 km) in width from east to west and 150 miles (240 km) in length. With 595,000 acres (2,410 km2), it is the nation’s largest swamp wilderness, containing nationally significant expanses of bottomland hardwoods, swamplands, bayous and back-water lakes.

Its wetlands, bayous and marshes are home to 300 species of birds, 90 species of fish and shellfish and 54 species of reptiles and amphibians, including the great American alligator. It owes much of its haunting and mysterious beauty to the towering, moss-draped bald cypress trees that thrive in its swamp waters.

For hundreds of years, the Basin's human dwellers—from the Native Americans who harvested its timber to the present-day Cajuns who hunt alligators in its murky depths—have subsisted on its many bountiful resources. In the second half of the 18th century, the region became a refuge for several thousand French colonists who had been expelled from Acadie, part of present-day Nova Scotia, for refusing to swear allegiance to the British crown and church. Known as the Acadians, the settlers adapted their way of life to the changeable nature of the Basin's wetland environment, where water levels fluctuate depending on the season, by favoring houseboats and campsites to more permanent homes. Many began growing sugarcane and other crops in the fertile bayou soil, while others made a living as loggers, hunters, trappers or fishermen.

The Acadian community grew and prospered, eventually giving birth to the distinctly Louisianan "Cajun" culture, known throughout the world for its food, music and unique dialect. Today, the Cajuns make up a significant part of southern Louisiana's population, and many continue to embrace the lifestyle and traditions of their ancestors.