A subtropical region of marsh, swamp, and grassland in southern Florida. The Everglades is bounded on the north by Lake Okeechobee, on the south by mangrove swamps and saltwater marshes, on the east by a limestone ridge topped with pine trees, and on the west by Big Cypress Swamp. Elevation ranges from about 15 feet (4.6 m) above sea level in the north to sea level in the south. Drainage southward from Lake Okeechobee and heavy rainfall are the chief sources of water for the Everglades.

The Everglades consists mainly of fields of saw grass (a tall sedge) and open water dotted with tree-covered islands (called hammocks and heads). Among the trees on these islands are palm, palmetto, gumbo-limbo, willow, and mahogany.

South of the Tamiami Trail (U.S. Highway 41) lies Everglades National Park, covering 2,354 square miles (6,097 km²). It includes part of the Everglades proper plus coastal mangrove swamps and a number of offshore islands. The park is noted for its varied wildlife, including herons, ibises, pelicans, spoonbills, otters, deer, alligators, and many kinds of snakes. Many endangered species, including the Florida cougar, Everglade kite, wood stork, hawksbill turtle, and American crocodile, are found within the park.

The Everglades was uninhabited until the 1840s, when Seminole Indians took refuge there from the United States Army after the Second Seminole War. A number of Seminoles still live there.

The Everglades originally covered more than 4,000 square miles (10,000 km²) and its water flowed slowly southward to the sea. Since the late 19th century, more than half of the Everglades has been drained by canals that divert its water for agricultural, industrial, and municipal purposes. This drainage has caused the loss of much plant and animal life. In addition, the Everglades has been damaged by pollution from nearby farms and cities and its ecology has been changed by the introduction of rapidly growing non-native plants that crowd out many native plants. In 1993, the United States Department of the Interior began a project to restore the Everglades to a more natural condition.