The Florida Keys are a coral cay archipelago in the southeast United States. They begin at the southeastern tip of the Florida peninsula, about 15 miles south of Miami, and extend in a gentle arc south-southwest and then westward to Key West, the westernmost of the inhabited islands, and on to the uninhabited Dry Tortugas. The islands lie along the Florida Straits, dividing the Atlantic Ocean to the east from the Gulf of Mexico to the west, and defining one edge of Florida Bay. At the nearest point, the southern tip of Key West is just 90 miles from Cuba. The Florida Keys are between about 23.5 and 25.5 degrees North latitude, in the subtropics. The climate of the Keys is defined as tropical according to Köppen climate classification. More than 95 percent of the land area lies in Monroe County, but a small portion extends northeast into Miami-Dade County, such as Totten Key. The total land area is 137.3 square miles. As of the 2000 census the population was 79,535, with an average density of 579.27 per square mile , although much of the population is concentrated in a few areas of much higher density, such as the city of Key West, which has 32% of the entire population of the Keys.
The city of Key West is the county seat of Monroe County. The county consists of a section on the mainland which is almost entirely in Everglades National Park, and the Keys islands from Key Largo to the Dry Tortugas.
The Keys were originally inhabited by Calusa and Tequesta Native Americans. They were later found and charted by Juan Ponce de León in 1513. De León named the islands Los Martires as they looked like suffering men from a distance. “Key” is derived from the Spanish Cayo, meaning small island. For many years, Key West was the largest town in Florida, and it grew prosperous on wrecking. The isolated outpost was well located for trade with Cuba, the Bahamas, and was on the main trade route from New Orleans. Improved navigation led to fewer shipwrecks, and Key West went into a decline in the late nineteenth century.
The Keys were long accessible only by water. This changed with the completion of Henry Flagler’s Overseas Railway in the early 1910s. Flagler, a major developer of Florida’s Atlantic coast, extended his Florida East Coast Railway down to Key West with an ambitious series of over-sea railroad trestles. Three hurricanes disrupted the project in 1906, 1909, and 1910.
One of the worst hurricanes to strike the U.S. made landfall near Islamorada in the Upper Keys on Labor Day, Monday 2 September. Winds were estimated to have gusted to 200 mph, raising a storm surge more than 17.5 feet above sea level that washed over the islands. More than 400 people were killed, though some estimates place the number of deaths at more than 600.
The Labor Day Hurricane is one of only three hurricanes to make landfall at Category 5 strength on the U.S. coast since reliable weather records began (about 1850). The other storms were Hurricane Camille (1969) and Hurricane Andrew (1992).
In 1935, new bridges were under construction to connect a highway through the entire Keys. Hundreds of World War I veterans working on the roadway as part of a government relief program were housed in non-reinforced buildings in three construction camps in the Upper Keys. When the evacuation train failed to reach the camps before the storm, more than 200 veterans perished. Their deaths caused anger and charges of mismanagement that led to a Congressional investigation.
The storm also ended the 23-year run of the Overseas Railway; the damaged tracks were never rebuilt, and the Overseas Highway (U.S. Highway 1) replaced the railroad as the main transportation route from Miami to Key West.
Seven Mile Bridge
One of the longest bridges when it was built, the Seven Mile Bridge connects Knight’s Key (part of the city of Marathon in the Middle Keys) to Little Duck Key in the Lower Keys. The piling-supported concrete bridge is 35,862 ft or 6.79 miles (10.93 km) long. The current bridge bypasses Pigeon Key, a small island that housed workers building Henry Flagler’s Florida East Coast Railway in the 1900s, that the original Seven Mile Bridge crossed. A 2.2-mile (3.5 km) section of the old bridge remains for access to the island, although it was closed to vehicular traffic on March 4, 2008. The aging structure has been deemed unsafe by the Florida Department of Transportation. Costly repairs, estimated to be as much as $34 million, were expected to begin in July 2008. Monroe County was unable to secure a $17 million loan through the state infrastructure bank, delaying work for at least a year. On June 14, 2008, the old bridge section leading to Pigeon Key was closed to fishing as well. While still open to pedestrians — walking, biking and jogging — if the bridge were closed altogether, only a ferry subsidized by Florida Department of Transportation and managed by the county would transport visitors to the island.
After the destruction of the Keys railway by the Labor Day Hurricane of 1935, the railroad bridges, including the Seven Mile Bridge, were converted to automobile roadways. U.S. 1 runs the length of the Keys and up the East Coast to Maine; the Keys section is also called the Overseas Highway.
Following the Cuban Revolution, many Cubans fled to South Florida. Key West traditionally had strong links with their neighbor ninety miles south by water, and large numbers of Cubans settled there. The Keys still attract Cubans leaving their home country, and stories of “rafters” coming ashore are not uncommon.
In 1982, the United States Border Patrol had established a roadblock and inspection points on US Highway 1, stopping all northbound traffic returning to the mainland at Florida City, to search vehicles for illegal drugs and illegal immigrants. The Key West City Council repeatedly complained about the roadblocks, which were a major inconvenience for people traveling from Key West, and hurt the Keys’ important tourism industry.
After various unsuccessful complaints and attempts to get a legal injunction against the blockade failed in federal court in Miami, on 23 April 1982 Key West mayor Dennis Wardlow and the city council declared the independence of the city of Key West, calling it the “Conch Republic”. After one minute of secession, he (as “Prime Minister”) surrendered to an officer of the Key West Naval Air Station , and requested one billion dollars in “foreign aid”.
The stunt succeeded in generating great publicity for the Keys’ plight, and the inspection station roadblock was removed. It also provided a new source of revenue for the Keys, and the Conch Republic has participated in later protests.
Many fortunes have been made through the smuggling of drugs into the United States by way of the Keys. Law enforcement has been a major addition over the years as smuggling increased and spread throughout most of the Keys. During the 1970s, this law enforcement was practically non-existent, and tons of cannabis came into the Keys by boat and were carried off the islands by tractor trailers. With the beginning of the “War on Drugs” in the 1980s, federal and state law enforcement agencies began their expansion in a futile effort to stop the smuggling. The smuggling groups adjusted their tactics, and although law enforcement began to make some arrests, drugs continued to pour through from Key West to Everglades City. The 1980s saw the rise of cocaine smuggling into the Keys by smaller boats with hidden compartments and various underwater containers attached to the bottom of vessels.
The Florida Keys are the exposed portions of an ancient coral reef. The northernmost island arising from the ancient reef formation is Elliott Key, in Biscayne National Park. North of Elliott Key are several small transitional keys, composed of sand built up around small areas of exposed ancient reef. Further north, Key Biscayne and places north are barrier islands, built up of sand.
The Florida Keys have taken their present form as the result of the drastic changes in sea level associated with recent glaciations or ice ages. Beginning some 130,000 years ago the Sangamonian Stage raised sea levels to approximately 25 feet above the current level. All of southern Florida was covered by a shallow sea. Several parallel lines of reef formed along the edge of the submerged Florida plateau, stretching south and then west from the present Miami area to what is now the Dry Tortugas. This reef formed the Key Largo limestone that is exposed on the surface from Soldier Key to the southeast portion of Big Pine Key and the Newfound Harbor Keys. The types of coral that formed Key Largo limestone can be identified on the exposed surface of these keys.
Starting about 100,000 years ago the Wisconsin glaciation began lowering sea levels, exposing the coral reef and surrounding marine sediments. By 15,000 years ago the sea level had dropped to 300 to 350 feet below the contemporary level. The exposed reefs and sediments were heavily eroded. Acidic water, which can result from decaying vegetation, dissolves limestone. Some of the dissolved limestone redeposited as a denser cap rock, which can be seen as outcrops overlying the Key Largo and Miami limestones throughout the Keys. The limestone that eroded from the reef formed oolites in the shallow sea behind the reef, and together with the skeletal remains of bryozoans, formed the Miami limestone that is the current surface bedrock of the lower Florida peninsula and the lower keys from Big Pine Key to Key West. To the west of Key West the ancient reef is covered by recent calcareous sand.
Just offshore of the Florida Keys along the edge of the Florida Straits is the Florida Reef . The Florida Reef extends from Fowey Rocks just east of Soldier Key to just south of the Marquesas Keys. It is the third-largest barrier reef system in the world.
The Keys are in the subtropics between 24 and 25 degrees north latitude but the keys have a true tropical climate. The climate and environment are closer to that of the Caribbean than the rest of Florida, though unlike the Caribbean’s volcanic islands, the Keys were built by plants and animals.
The Upper Keys islands are composed of sandy-type accumulations of limestone grains produced by plants and marine organisms. The Lower Keys are the remnants of large coral reefs, which became fossilized and exposed as sea level declined.
The natural habitats of the Keys are upland forests, inland wetlands and shoreline zones. Soil ranges from sand to marl to rich, decomposed leaf litter. In some places, “caprock” covers the ground. Rain falling through leaf debris becomes acidic and dissolves holes in the limestone, where soil accumulates and trees root.
The climate is tropical savanna and the Keys are the only frost-free place in Florida. There are two main “seasons”: hot, wet, and humid from about June through October, and somewhat drier and cooler weather from November through May. Many plants grow slowly or go dormant in the dry season. Some native trees are deciduous, and drop their leaves in the winter or with spring winds.
The Keys have distinctive plant and animals species, some found nowhere else in the United States, as the Keys define the northern extent of their ranges. The climate also allows many imported plants to thrive. Nearly any houseplant known to commerce, and most landscape plants of the South, can thrive in the Keys climate. Some exotic species which arrived as landscape plants now invade and threaten natural areas.
The native flora of the Keys is diverse, including members of both temperate families, such as red maple , slash pine and oaks, growing at the southern end of their ranges, and tropical families, including mahogany (Swietenia mahagoni), gumbo limbo (Bursera simaruba), stoppers (Eugenia spp.), Jamaican dogwood (Piscidia piscipula), and many others, which grow only as far north as 25 or 26 degrees north latitude.
Several plants that are popularly thought of as exemplifying Keys landscapes are in fact not native. These include coconut palm, bougainvillea, hibiscus, and papaya.
The well-known and very sour Key lime (or Mexican lime) is a naturalized species, apparently introduced from the Yucatán Peninsula of Mexico, where it had previously been introduced from Malaysia by explorers from Spain. The tree grows vigorously and has thorns, and produces golf-ball-size yellow fruit which is particularly acidic and uniquely fragrant. Key lime pie gets its name from the fruit.
The Keys are also home to unique animal species, including the Key deer, protected by the National Key Deer Refuge, the American crocodile, and the Key Largo woodrat. The Key Largo Woodrat is found only in the northern part of its namesake island, and is a focus of management activities in Crocodile Lake National Wildlife Refuge. About 70 miles west of Key West is Dry Tortugas National Park, one of the most isolated and therefore well-preserved in the world. The name derives from the fact that when Spanish explorers arrived no fresh water could be found, and the small hump-shaped islands look like tortoise (tortuga in Spanish) shells from a distance.
The waters surrounding the Keys are part of a protected area known as the Florida Keys National Marine Sanctuary.
The Keys are regularly threatened by tropical storms and hurricanes, leading to evacuations to the mainland. Untouched for many years, a carefree attitude led many residents to view “mandatory” evacuations as “voluntary” and “voluntary” evacuation orders as nothing at all. The attitude proved dangerous when Hurricane Georges, after tearing up much of the Caribbean, caused damage and extensive flooding in the Lower Keys in 1998, before making landfall in Mississippi. In 2005, Hurricanes Katrina, Rita and Wilma affected the Keys (although none made a direct hit), causing widespread damage and flooding. The most severe hurricane to hit the area was the Labor Day Hurricane of 1935, a Category 5 hurricane.
Tropical cyclones present special dangers and challenges to the entire Keys. Because no area of the islands is more than 20 feet above sea level (and many are only a few feet elevation), and water surrounds the islands, nearly every neighborhood is subject to devastating flooding as well as hurricane winds. In response, many homes in the Keys are built on concrete stilts with the first floor being not legally habitable and enclosed by breakaway walls that are not strongly attached to the rest of the house. Nonetheless, Monroe County, as reported in the Federal Register, has estimated that there are between 8,000 and 12,000 illegal enclosures inhabited by people.
Because of the threat from storm surge, evacuations are routinely ordered when the National Weather Service issues a hurricane watch or warning, and are sometimes ordered for a tropical storm warning. Evacuation of the Keys depends on causeways and the two-lane highway to the mainland. Time estimates for evacuating the entire Keys range from 12 to 24 hours. Evacuation estimates are significant in emergency planning, of course, but also because they are a factor in local and state regulations for controlling development. The building permit allocation was increased in 2005 when local governments reduced estimates for evacuation.
In the active hurricane seasons of 2004 and 2005, the Keys were under mandatory evacuation orders several times. In August 2004, Hurricane Charley passed about 70 miles west of Key West, bringing tropical storm winds to the lower keys. The lower keys were evacuated in preparation for Hurricane Ivan in September, 2004 and Hurricane Dennis in July 2005, but neither hurricane came close enough to the Keys to do much damage. Hurricane Katrina, which went on to devastate parts of Louisiana and Mississippi, moved through south Florida in August 2005 and tracked southwest past Key West, causing minor damage and flooding. Hurricane Rita, which went on to destroy parts of Louisiana and Texas, grew from a tropical storm to a Category 2 hurricane as it moved westward from the Bahamas, passing south of Key West and causing damage and surge flooding as far north as Key Largo. In October 2005, Hurricane Wilma became the most devastating hurricane to hit the Keys in decades when it passed just northwest of Key West. The low-lying parts of the city were left under 3 to 6 feet of water from the storm surge, and major flooding was reported throughout the Keys up to Key Largo.
The main chain of Keys islands can be traveled by motor vehicles on the Overseas Highway, a 127-mile section of U.S. 1, which runs from Key West to Fort Kent, Maine in its entirety. The highway was built parallel to the original route of the Overseas Railway, which was not rebuilt following the Labor Day hurricane of 1935. Even before the hurricane, road sections and highway bridges allowed automobile traffic to travel from Miami to Lower Matecumbe Key, where a car ferry connected with another roadway section through the Lower Keys. Following the hurricane, some of the original railway bridges were converted to carry the highway roadbeds. These bridges were used until the 1980s, when new highway bridges were built alongside. Many of the original railroad and highway bridges remain today as pedestrian fishing piers.
Despite this reconstruction, U.S. 1 was not widened on a large scale, and today most of the route consists of just two lanes. Due to their tropical climate, the Florida Keys attract several hundred thousand tourists annually. While some visitors arrive via Key West International Airport and Florida Keys Marathon Airport in Marathon, cruise ship or ferry from Miami or Fort Myers, the vast majority of tourists drive down from the mainland on U.S. 1. This influx of traffic, coupled with the two-lane nature of U.S. 1 through most of its length in the Keys, and the fact that no alternative road routes are available mean that Monroe County has the highest per capita rate of fatal automobile accidents in the state of Florida.
Some residents have a separatist “Conch Republic” attitude. The major industries are tourism and fishing. Ecotourism is also part of this, with many visitors scuba diving in the area’s protected waters. A new ferry now takes riders between Key West and Fort Myers, due north on the mainland, along the western edge of Florida Bay.