Swamplands USA is a two-part documentary that investigates the swamp-dwellers -- both animals and humans -- who live and work with nature in America's largest and least-known wetlands. Each one-hour episode features a different swamp: The Okefenokee Swamp in Georgia, a black and still expanse of water topped with thousands of lily pads, which is home to alligators, fishing spiders and giant salamanders; and The Atchafalaya Swamp, an immense floodplain in the heart of Louisiana, which provides refuge for an astonishing array of wildlife, including alligators, river shrimp and an array of secretive amphibians.