Everglades

The Everglades is a natural region of flooded grasslands in the southern portion of the U.S. state of Florida, comprising the southern half of a large drainage basin within the Neotropical realm. The system begins near Orlando with the Kissimmee River, which discharges into the vast but shallow Lake Okeechobee. Water leaving the lake in the wet season forms a slow-moving river 60 miles (97 km) wide and over 100 miles (160 km) long, flowing southward across a limestone shelf to Florida Bay at the southern end of the state. The Everglades experiences a wide range of weather patterns, from frequent flooding in the wet season to drought in the dry season. Throughout the 20th century, the Everglades suffered significant loss of habitat and environmental degradation.

Human habitation in the southern portion of the Florida peninsula dates to 15,000 years ago. Before European colonization, the region was dominated by the native Calusa and Tequesta tribes. With Spanish colonization, both tribes declined gradually during the following two centuries. The Seminole, formed from mostly Creek people who had been warring to the North, assimilated other peoples and created a new culture after being forced from northern Florida into the Everglades during the Seminole Wars of the early 19th century. After adapting to the region, they were able to resist removal by the United States Army.

Migrants to the region who wanted to develop plantations first proposed draining the Everglades in 1848, but no work of this type was attempted until 1882. Canals were constructed throughout the first half of the 20th century, and spurred the South Florida economy, prompting land development. In 1947, Congress formed the Central and Southern Florida Flood Control Project, which built 1,400 miles (2,300 km) of canals, levees, and water control devices. The Miami metropolitan area grew substantially at this time and Everglades water was diverted to cities. Portions of the Everglades were transformed into farmland, where the primary crop was sugarcane. Approximately 50 percent of the original Everglades has been developed as agricultural or urban areas.

Following this period of rapid development and environmental degradation, the ecosystem began to receive notable attention from conservation groups in the 1970s. Internationally, UNESCO and the Ramsar Convention designated the Everglades a Wetland Area of Global Importance. The construction of a large airport 6 miles (10 km) north of Everglades National Park was blocked when an environmental study found that it would severely damage the South Florida ecosystem. With heightened awareness and appreciation of the region, restoration began in the 1980s with the removal of a canal that had straightened the Kissimmee River. However, development and sustainability concerns have remained pertinent in the region. The deterioration of the Everglades, including poor water quality in Lake Okeechobee, was linked to the diminishing quality of life in South Florida's urban areas. In 2000 the Comprehensive Everglades Restoration Plan was approved by Congress to combat these problems, which at that time was considered the most expensive and comprehensive environmental restoration attempt in history; however, implementation faced political complications.

The first written record of the Everglades was on Spanish maps made by cartographers who had not seen the land. They named the unknown area between the Gulf and Atlantic coasts of Florida Laguna del Espíritu Santo ("Lake of the Holy Spirit"). The area was featured on maps for decades without having been explored. Writer James Grant Forbes stated in 1811, "The Indians represent [the Southern points] as impenetrable; and the [British] surveyors, wreckers, and coasters, had not the means of exploring beyond the borders of the sea coast, and the mouths of rivers".

British surveyor John Gerard de Brahm, who mapped the coast of Florida in 1773, called the area "River Glades". The name "Everglades" first appeared on a map in 1823, although it was also spelled as "Ever Glades" as late as 1851. The Seminole call it Pahokee, meaning "Grassy Water". The region was labeled "Pa-hai-okee" on a U.S. military map from 1839, although it had earlier been called "Ever Glades" throughout the Second Seminole War.

A 2007 survey by geographers Ary J. Lamme and Raymond K. Oldakowski found that the "Glades" has emerged as a distinct vernacular region of Florida. It comprises the interior areas and southernmost Gulf Coast of South Florida, largely corresponding to the Everglades itself. It is one of the most sparsely populated areas of the state.

The geology of South Florida, together with a warm, wet, subtropical/tropical climate, provides conditions well-suited for a large marshland ecosystem. Layers of porous and permeable limestone create water-bearing rock and soil that affect the climate, weather, and hydrology of South Florida. The properties of the rock underneath the Everglades can be explained by the geologic history of the state. The crust underneath Florida was at one point part of the African region of the supercontinent Gondwana. About 300 million years ago, North America merged with Africa, connecting Florida with North America. Volcanic activity centered on the eastern side of Florida covered the prevalent sedimentary rock with igneous rock. Continental rifting began to separate North America from Gondwana about 180 million years ago. When Florida was part of Africa, it was initially above water, but during the cooler Jurassic Period, the Florida Platform became a shallow marine environment in which sedimentary rocks were deposited. Through the Cretaceous Period, most of Florida remained a tropical sea floor of varying depths. The peninsula has been covered by seawater at least seven times since the bedrock formed.