Everglades, marshy, low-lying subtropical savanna area, c.4,000 sq mi (10,000 sq km), S Fla., extending from Lake Okeechobee S to Florida Bay. Characterized by water, sawgrass, hammocks (islandlike masses of vegetation), palms, pine and mangrove forests, and solidly packed black muck (resulting from millions of years of vegetation decay in near-stagnant water), the Everglades receives an annual average rainfall of more than 60 in. (152 cm), mainly in the summer. Big Cypress Swamp, to the northwest, and Lake Okeechobee are the chief sources of its water. Low limestone rises rim the area, acting as a natural retaining wall. The wildlife-rich area is home to such endangered species as the Florida panther, American crocodile, and manatee, and also home to a sizable, non-native Burmese python population.

Colonial expeditions in the 1500s found Native Americans living in the Everglades; in the late 1830s the Everglades was the scene of military operations against the Seminole. Large tracts of land were drained in the late 19th and early 20th cent., when the area was considered rich in agricultural potential, but only lands immediately bordering Lake Okeechobee were farmed. Winter vegetables and sugarcane are now the main crops; some cattle are raised. After great fires in 1939 (abetted by overdrainage), the first thorough studies of the Everglades concluded that most of the southern part was unfit for cultivation.

A ring dike had been constructed around Lake Okeechobee in the 1920s to prevent hurricanes from blowing water out of the lake, and massive additional flood control projects were undertaken following 1947 hurricanes. These, land development, and roadbuilding, especially the Tamiami Trail (U.S. 41), disrupted the shallow, 60-mile (100-km) wide “River of Grass” that had flowed across the Everglades, altering seasonal rhythms, channeling water to the Gulf of Mexico so as to create shortages that have damaged plant and animal life, and causing increased salinity in Florida Bay to the south.

In 1994, Florida—and in 1996 the federal government—launched long-term reclamation projects, aimed at removing levees, reflooding drained swampland, and otherwise “replumbing” the Everglades. Legislation enabling the multibillion-dollar project, with the cost split between the state and the U.S. government, was passed by Congress in 2000. In 2008, however, the South Florida Water Management District suspended work on a reservoir to be used in restoration, in anticipation of the sizable costs of a planned state purchase of citrus and sugar farmland between Okeechobee and the preserved portions of the Everglades. Work on the reservoir was later (2010) ordered resumed by the federal judge overseeing reclamation, and the proposed purchase of farmland was scaled back significantly.

At the southwestern end of Florida is Everglades National Park and Expansion, (1,508,580 acres/610,761 hectares), est. 1947. Big Cypress National Preserve and Addition (est. 1974) adjoins it to the north. See National Parks and Monuments (table)national parks and monuments (table).

See M. S. Douglas, The Everglades (1947, repr. 1988); C. S. Rom, Everglades (1989); M. Grunwald, The Swamp (2006).

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