Biscayne National Park is a U.S. national park located south of Miami, Florida, in Miami-Dade County. The park protects Biscayne Bay and its offshore barrier reefs. Along the bay’s shore is a large mangrove forest. The park covers 172,971 acres, of which 9,075 acres are on land. It includes Elliott Key, the park’s largest island and northernmost true Florida Key, formed from old coral. Islands farther north are transitional, made of both coral and sand. The offshore area includes the northern part of the Florida Reef, one of the world’s largest coral reefs.
The park preserves four ecosystems: Florida mangroves along the shoreline, shallow waters of Biscayne Bay, coral limestone keys, and the Florida Reef. Shoreline swamps near the mainland and islands provide a home for young fish, shellfish, and crustaceans. Bay waters support adult and young fish, seagrass, sponges, soft corals, and manatees. Keys have tropical plants, including endangered cacti and palms, and their beaches are nesting areas for endangered sea turtles. Offshore reefs and waters are home to over 200 fish species, pelagic birds, whales, and hard corals. Sixteen endangered species, including Schaus’ swallowtail butterflies, smalltooth sawfish, manatees, and green and hawksbill sea turtles, live in the park. The park also has a small number of threatened American crocodiles and a few American alligators.
People from the Glades culture lived in the Biscayne Bay area as far back as 10,000 years ago. Later, rising sea levels covered the bay. The Tequesta people lived on the islands and shoreline from about 4,000 years ago until the 16th century, when Spain claimed Florida. Reefs caused shipwrecks from Spanish times through the 20th century, with over 40 documented wrecks in the park. While islands were farmed in the 19th and early 20th centuries, rocky soil and hurricanes made farming hard to continue.
In the early 20th century, wealthy Miamians built homes and clubs on the islands. Mark C. Honeywell’s guesthouse on Boca Chita Key had a fake lighthouse. The Cocolobo Cay Club was owned by several people, including President Richard Nixon’s friend, and was visited by four U.S. presidents. Stiltsville, a floating community built in the 1930s, offered gambling and alcohol during Prohibition. After the 1959 Cuban Revolution, the CIA and Cuban exile groups used Elliott Key to train people to enter Cuba.
Biscayne Bay was originally proposed to be part of Everglades National Park but was removed to help establish Everglades. The area stayed undeveloped until the 1960s, when plans were made to build homes, a seaport, and factories on the mainland. Two fossil-fueled power plants and two nuclear power plants were built on the bay’s shores. Concerns about development led to the 1968 creation of Biscayne National Monument. The park was expanded in 1980 as Biscayne National Park. Boaters use the park heavily, and the mainland visitor center and a jetty at Black Point Marina are the only land-based access points.
Geography
Biscayne National Park covers 172,971 acres in Miami-Dade County, southeast Florida. It stretches from just south of Key Biscayne to just north of Key Largo. Most of the park is open water, but there are 42 islands inside the park, including Soldier Key, the Ragged Keys, Sands Key, Elliott Key, Totten Key, and Old Rhodes Key. These islands are part of the northernmost section of the Florida Keys. The Safety Valve is a wide, shallow opening between the Ragged Keys and Key Biscayne. It helps storm surge water flow out of the bay after tropical storms.
The park’s eastern edge is marked by a line in the ocean where the water is 60 feet deep, near the Florida Reef. The western edge includes land near Cutler Ridge and Mangrove Point, extending a few hundred meters inland. The only direct way to reach the park from the mainland is at the Convoy Point Visitor Center, near the park headquarters. The park’s southwestern edge is next to the Turkey Point Nuclear Generating Station and its cooling canals.
The southern part of Biscayne Bay lies between Elliott Key and the mainland, with the Intracoastal Waterway passing through it. The park is next to the Florida Keys National Marine Sanctuary on the east and south sides and John Pennekamp Coral Reef State Park to the south. Only 9,075 acres of the park are land, with 4,250 acres on offshore islands and 4,825 acres in mainland mangrove swamps. The park was once considered part of Everglades National Park but was excluded to help establish the Everglades park in 1947.
Biscayne Bay is the southernmost point of the Atlantic barrier islands, like Key Biscayne, and the northernmost point of the Florida Keys, like Elliott Key. The islands differ from barrier islands because they are made of coral limestone covered by thin soil, while barrier islands are mostly made of sand. Biscayne Bay is between low ridges of oolitic Miami Limestone on the west, forming Cutler Ridge, and coral-based Key Largo limestone under Elliott Key and other southern keys. The Miami Limestone was formed in turbulent lagoon waters.
The Key Largo Limestone is a fossilized coral reef from about 75,000 to 125,000 years ago. The Miami Formation became its current shape later during a cold period when fresh water solidified the lagoon deposits. The Key Largo Limestone is a thick, rough stone made of coral, 69 to 200 feet thick. Because of its reef origins, beaches on Elliott Key and Old Rhodes Key are rocky, while Sands Key has sandy beaches.
Biscayne Bay is a shallow, partly enclosed lagoon averaging 10 feet deep. Mangrove forests cover both the mainland edges and the islands. The park includes parts of Biscayne Bay with thin sediment called "hardbottom" and underwater grasses like turtlegrass and shoal grass.
In the early and mid-20th century, canals were built to control water in Florida and drain the Everglades. These canals now carry water from farmland in the southeastern Everglades into Biscayne Bay. Before the canals, most fresh water came from rain and groundwater, but now the canals change the salt levels in the bay, bringing in sediment, pollution, and saltwater into the Biscayne aquifer. The Comprehensive Everglades Restoration Plan (CERP) was created in 2000 to fix these issues. It aims to restore natural water flow to Everglades National Park and address problems from water being diverted into Biscayne Bay. A part of CERP, the Biscayne Bay Coastal Wetlands Project (BBCW), helps move fresh water slowly through creeks and marshes instead of large, sudden releases through canals.
Human history
Native Americans lived in lower Florida 10,000 years ago, when ocean levels were lower and Biscayne Bay had less water. Water levels rose around 4,000 years ago, flooding the bay. Archaeologists think any signs of people from that time are now underwater; none remain on dry land in the park. The Cutler Fossil Site, near the park, has evidence of human activity dating back at least 10,000 years.
The earliest proof of humans in Biscayne dates to about 2,500 years ago, with piles of conch and whelk shells left by the Glades culture. The Glades culture was followed by the Tequesta people, who lived along Biscayne Bay’s shores. The Tequesta were a community that stayed in one place, eating fish and other sea life, but did not grow crops. A site on Sands Key has artifacts, like broken pottery and worked shells, showing people lived there from at least 1000 CE until about 1650, after Europeans arrived. Fifty important archaeological sites have been found in the park.
Juan Ponce de León explored the area in 1513, discovering the Florida Keys and meeting the Tequesta on the mainland. Other Spanish explorers came later in the 1500s, and Florida became part of Spain. The Tequesta were moved by the Spanish government to the Florida Keys, and the mainland became empty. Ponce de León named the bay “Chequescha” after the people, and the name later became “Tequesta.” The current name comes from a shipwrecked Basque sailor called “Biscaino” or “Viscayno,” or from a reference to the Bay of Biscay.
Spanish treasure ships often passed near the Florida Keys but were sometimes caught in hurricanes. There are 44 recorded shipwrecks in the park from the 1500s to the 1900s. At least two 1700s Spanish ships sank in the area. A Spanish galleon called Nuestra Senora del Popolo is believed to have wrecked in 1733, but its location is unknown. Another ship, HMS Fowey, sank in 1748 near Legare Anchorage. Its discovery in 1975 led to a court case that declared it an archaeological site, not a place for treasure hunting. Forty-three wrecks are listed on the National Register of Historic Places in the Offshore Reefs Archaeological District, which stretches 30 miles along the seaward side of Biscayne National Park’s keys. In the 1700s, Elliott Key was said to be the base of two pirates named Black Caesar, remembered by Caesar’s Creek between Elliott and Old Rhodes Key.
The first permanent European settlers in the Miami area arrived in the early 1800s. Small farms on Elliott Key grew crops like key limes and pineapples. John James Audubon visited Elliott Key in 1832. Colonel Robert E. Lee studied the area around Biscayne Bay in 1849 for possible military sites. After the American Civil War ended in 1865, some Confederates passed through the area while trying to escape to Cuba. Elliott Key was a short stop for John C. Breckinridge, a former U.S. vice president and Confederate general, during his escape. Few people lived in the park area until 1897, when Israel Lafayette Jones, an African-American property manager, bought Porgy Key for $300 (equivalent to $11,600 in 2025). The next year, Jones bought Old Rhodes Key and grew limes and pineapples there.
In 1911, Jones bought Totten Key, a 212-acre (86 ha) former pineapple plantation, for $1 per acre. He sold it in 1925 for $250,000. Before his death in 1932, Jones’ plantations were among the largest lime producers on Florida’s east coast.
Carl G. Fisher, who helped develop Miami Beach, bought Adams Key (once called Cocolobo Key) in 1916 and built the Cocolobo Cay Club in 1922. The two-story club had ten guest rooms, a dining room, and a recreation lodge. Visitors included Warren G. Harding, Albert Fall, T. Coleman du Pont, Harvey Firestone, Jack Dempsey, Charles F. Kettering, Will Rogers, and Frank Seiberling. Israel Jones’ sons, Lancelot and Arthur, left the lime business after competition from Mexican limes and after damaging hurricanes in 1938. They became full-time fishing guides at the Cocolobo Club. The club declined after the 1929 economic crash but was revived in 1934 by Garfield Wood. Clients included President Herbert Hoover and his family. The Joneses also supplied the club with fish, lobster, and crabs. Arthur and Lancelot Jones were the largest landowners and only permanent residents of the lower Biscayne Bay keys during the 1960s. Wood sold the club to Miami banker Bebe Rebozo in 1954, who renamed it the Coco Lobo Fishing Club. Clients guided by the Joneses in the 1940s and 1950s included senators John F. Kennedy, Lyndon Johnson, Richard Nixon, Herman Talmadge, and George Smathers.
During the Cold War, the future park area was used to train Cuban exiles for missions in Cuba. Elliott Key was used by the Central Intelligence Agency in the 1960s to prepare for the Bay of Pigs invasion. The largest facility was Ledbury Lodge, the only hotel ever built on the key. In 1988, Cuban exiles were arrested for trying to use the key for a mock landing. Farther north, exiled Venezuelan president Marcos Pérez Jiménez lived on Soldier Key until he was extradited in 1963.
As modern communities grew around Miami, developers looked to southern Miami-Dade County for new projects. The undeveloped keys south of Key Biscayne were seen as good places for development.
Starting in the 1890s, local groups pushed for a causeway to connect the mainland. One plan included building a highway linking the Biscayne Bay keys to the Overseas Highway at Key Largo and to barrier islands north of the area. At the same time, pressure grew for industrial development in South Florida. This led to conflicts between those who wanted to build homes and resorts and those who wanted to build factories and infrastructure. On December
Activities
Biscayne National Park is open all year. Camping is easiest during the winter months because there are fewer mosquitoes on the keys. The Biscayne National Park Institute offers half-day and full-day tours in the park. These tours include activities such as snorkeling, hiking, paddling, and sailing from the park headquarters. Boat trips to Boca Chita Key and the area’s lighthouses are also available. Licensed private companies provide guided tours for fishing, snorkeling, sailing, and sightseeing.
Access to the park from the mainland is limited to the area near the Dante Fascell Visitor Center at Convoy Point. All other parts of the park can only be reached by private or concessioner boats. Activities available in the park include boating, fishing, kayaking, windsurfing, snorkeling, and scuba diving. Miami-Dade County operates four marina parks near the park. Homestead Bayfront Park is next to the park headquarters at Convoy Point. Black Point Park, farther south, provides access to Adams and Elliott Keys. Matheson Hammock Park is near the northern end of the park, and Crandon Park is located on Key Biscayne.
Although Biscayne National Park is federally protected, fishing in the park is managed by the state of Florida. People who fish in Biscayne must have a Florida recreational saltwater fishing license. Fishing is allowed only for certain species, including designated sport fish, spiny lobster, stone crab, blue crab, and shrimp. Tropical reef fish, sharks, conch, sea urchins, and other marine life cannot be collected. Reef life, such as coral and sponges, is also protected from being taken by visitors. Lobstering is not allowed in the Biscayne Bay-Card Sound Lobster Sanctuary, which is managed by Florida to protect spiny lobster breeding areas. This sanctuary covers much of Biscayne Bay.
A private company offers tours from the park headquarters into the bay and to the keys. Most tours operate during the winter months, from January to April. Personal watercraft are not allowed in Biscayne or most other national parks. However, private powerboats and sailboats are permitted.
Most of Biscayne’s permanent facilities are located on the offshore keys. A ranger station, campground, and 36 boat slips are on Elliott Key. A single loop trail connects the harbor to the oceanfront, and a path along the Spite Highway runs the length of the island. Adams Key is a day-use area for visitors, though two Park Service residences are on the island. Boca Chita Key is the most-visited island, with a campground and picnic areas. The Boca Chita Lighthouse is sometimes open to visitors when staff are available.
Snorkeling and scuba diving on the offshore reefs are popular activities. These reefs have caused many shipwrecks. Some wrecks are included in ranger-led snorkeling tours and are part of the Maritime Heritage Trail, the only underwater archaeological trail in the National Park Service system. The wrecks of the Arratoon Apcar (sank 1878), Erl King (1891), Alicia (1905), Lugano (1913), and Mandalay (1966) are on the trail, along with an unknown wreck from the 1800s and the Fowey Rocks Lighthouse. The Alicia, Erl King, and Lugano wrecks are deeper and best for scuba diving. The Mandalay wreck is shallower and popular for snorkeling.
Historical structures
Most of Biscayne National Park is covered by water, but the islands contain protected historical buildings and areas. Shipwrecks are also protected in the park, and the waters near the park are part of a protected historic area.
Stiltsville was created in the 1930s by Eddie "Crawfish" Walker as a small community of wooden structures built on supports in a shallow part of Biscayne Bay, near Key Biscayne. At its peak in the 1960s, Stiltsville had 27 buildings. Fires and hurricanes caused many buildings to be lost, leaving only six by 2021, none of which were built before the 1960s. The site was added to Biscayne National Park in 1985, with an agreement to honor existing leases until July 1, 1999. Hurricane Andrew damaged most of Stiltsville in 1992. The National Park Service now works to preserve the area, which is currently unoccupied. A trust will manage the site, and it will be used for camping, education, and research.
Biscayne National Park includes navigational aids and a decorative structure that looks like a lighthouse. The Fowey Rocks Light is a cast iron skeleton-frame structure built in 1878. It was already inside the park’s boundaries and was acquired by the Park Service on October 2, 2012. The Pacific Reef Light, located about three miles (4.8 km) offshore from Elliott Key, was originally built in 1921. It was replaced in 2000, and its lantern is now displayed in a park in Islamorada.
Industrialist Mark C. Honeywell, a member of the Cocolobo Club, purchased Boca Chita Key in 1937 and expanded its facilities to include a small lighthouse. The key had several structures, such as an imitation lighthouse made of coral rock and topped with a wire cage resembling a lighthouse lantern, and a jetty on the north side. Honeywell owned the key until 1945. He and his wife, Olive Honeywell, also built a chapel, guesthouse, seawalls, and utility buildings on the island.
The structures on Boca Chita Key are managed as a cultural landscape, showing how the area was used as a retreat for wealthy people. Other areas include abandoned plantations built by Israel Jones and his sons, and the Sweeting Homestead on Elliott Key. The wooden buildings linked to these plantations, as well as those from the Cocolobo Cay Club and Boca Chita Key, were destroyed by fire and hurricanes.
Ecology
South Florida is an area where two major regions meet—the Nearctic and Neotropical realms—creating a wide range of plant and animal life. This mix of regions allows visitors to see many species, especially birds, that are not found elsewhere in North America. The park has four different ecosystems, each with its own plants and animals. These include mangrove swamps, lagoons, island keys, and offshore reefs, which support many types of wildlife. In this semi-tropical environment, seasons are mainly different by how much rain falls. Summers are warm to hot and wet, with occasional tropical storms. Winters are only slightly cooler but drier. The salt level in the bay changes with the seasons, with lower salt levels in the wet summer, especially on the west side where fresh water flows in.
Hundreds of fish species live in the park’s waters, including more than 50 crustacean species like isopods and giant blue land crabs, about 200 bird species, and around 27 mammal species, both on land and in the water. Mollusks include bivalves, snails, sea hares, sea slugs, and two types of cephalopods: the Caribbean reef octopus and the Caribbean reef squid.
The protected open waters of the bay and the nearby keys provide resting spots for birds migrating between North America, the Caribbean, and South America. Many birds heading south stop at Bill Baggs Cape Florida State Park on Key Biscayne in the fall before crossing Biscayne Bay. Birds returning north in the spring rest at Elliott Key. Most of the small bird migrants are warblers, including ovenbirds, palm warblers, American redstarts, common yellowthroats, prairie warblers, worm-eating warblers, and black-throated blue warblers. Migrating birds of prey include short-tailed hawks, sharp-shinned hawks, merlins, peregrine falcons, and swallow-tailed kites. Bald eagles and ospreys build nests in the park. Both white-tailed and red-tailed tropicbirds are seen in the park, as are American flamingos, some of which may have escaped from captivity.
The mainland shorelines are covered by a wet area where red mangroves and black mangroves grow in shallow water, and white mangroves grow farther inland. The roots of these trees create a sheltered habitat for crabs, fish, and wading birds. The water in the mangrove thickets is home to young fish, mollusks, and crustaceans that need a quiet, protected place before moving to open waters. Mangroves drop about 2 to 4 tons of leaves per acre each year, providing food for fish, worms, and crustaceans. Because the carbon in the leaves is used by animals, mangrove swamps may store two to three times more carbon than forests on land. The mangrove forest along Biscayne Bay is the longest on Florida’s east coast. Shoreline and island mangroves, along with the bay, are important nurseries for marine life in southeast Florida.
The salt-tolerant mangroves have grown inland as fresh water has been redirected into the bay, replacing freshwater sawgrass marshes. A coastal storm surge levee near the park’s western edge has cut off former freshwater marshes from their water sources. At the same time, tidal water does not reach the interior of the mangrove area, limiting the mixing of salt and fresh water.
Birds along the shoreline include yellow-crowned night herons, loggerhead shrikes, prairie warblers, and shorebirds. Mangrove cuckoos, a species that is hard to see, may be spotted at Convoy Point and Black Point. Biscayne has one of the largest populations of mangrove cuckoos in Florida.
The edges of the park are home to the threatened American crocodile. Cooling water canals near the Turkey Point power plant, which are filled with warm water, have created an ideal nesting environment for crocodiles. While both crocodiles and American alligators live in southern Florida, alligators are rare in Biscayne because they prefer fresh water farther inland, while crocodiles can live in the saltier waters of the park.
The open waters of the bay are home to fish, mollusks, and crustaceans that live on sea grasses or eat each other. The shallow lagoon is a good habitat for diving birds like anhingas, cormorants, and diving ducks. The bay also supports young sea animals that have left the safety of mangrove areas. Manatees often swim in the calm waters of the bay. Double-crested cormorants live in the bay all year. Winter visitors include northern gannets, American white pelicans, and common loons. The bay also has a population of common bottlenose dolphins.
Biscayne Bay is a shallow lagoon with little change in depth or salt level. Instead of a vertical change in salt level, the bay has a horizontal change, with fresh water entering from canals on the west side and seawater coming in through gaps in the keys and through the safety valve section of shoals. The salt level in the bay is highest in June. Changes in the bay’s salt levels have harmed some species, like red drum. Biscayne Bay and Florida Bay are important nurseries for red grouper and gray snapper. The bottom of the lagoon has sponges and soft corals in areas where grasses cannot grow. Three main types of seagrass are found in the park: turtlegrass, shoal grass, and manatee grass. Johnson’s seagrass is also found in small amounts in the bay, which is at the southern end of its range. About 75% of the central bay floor is covered by grasses. Damage to seagrass beds from boat propellers or anchors is a serious problem. About 200 such incidents are recorded each year, and full recovery can take up to 15 years. Commercial shrimp trawling is allowed in the park, but while it does not harm grasses, it damages soft corals and sponges.
Elliott Key is the largest island in the park, covering 1,650 acres and about 8.1 miles long by 0.62 miles wide. The next largest is Old Rhodes Key at 660 acres, followed by Sands Key at 420 acres, Totten Key at 380 acres, and Little Totten Key at 200 acres. There are 37 smaller islands arranged in a north-south line 5 to 8.7 miles east of the mainland. The islands change from rocky barrier islands in the north to coral rock platforms in the south. All are covered with mangroves, and their interiors have subtropical plants like gumbo limbo, mahogany, ironwood, torchwood, and satinleaf. Insects include Schaus’ swallowtail, an endangered species, and large numbers of mosquitoes during the wet season, which are eaten by dragonflies. Marsh rabbits, raccoons, mice, and rats are the main mammal species. Reptiles include rattlesnakes, lizards, and occasionally crocodiles.
The keys are a transitional area that can support unexpected birds, often Caribbean species that have wandered near the mainland. The interiors of the keys are visited by warblers and the hawks that hunt them. Coastal areas are home to ruddy turnstones and least sandpipers. Gulls
Climate
Biscayne National Park has a tropical climate because it is located in southern Florida. Southern Miami-Dade County has a tropical savanna climate, and the park is near an area with a tropical monsoon climate. The year is divided into two seasons: the dry season from November to April and the wet season from May to October. During the dry season, average temperatures range from 66 to 76 °F (19 to 24 °C), with about 2.1 inches (53 mm) of rain each month. During the wet season, average temperatures range from 76 to 85 °F (24 to 29 °C), with about 5.39 inches (137 mm) of rain each month. The wet season often overlaps with hurricane season, when thunderstorms are common.
Like many places in southern Florida, Biscayne National Park is sometimes hit by hurricanes. These storms can cause temporary park closures and require repairs to facilities. A powerful hurricane that hits directly can cause serious damage, especially to human-made structures, because the natural environment of the park is adapted to such events. Major hurricanes that have affected Biscayne include storms in 1835 and 1904, the 1906 Florida Keys hurricane, the 1926 Miami hurricane, the 1929 Bahamas hurricane, the 1935 Labor Day hurricane, the 1935 Yankee hurricane, the 1941 Florida hurricane, the 1945 Southeast Florida hurricane, the 1948 Miami hurricane, Hurricane King in 1950, Hurricane Donna in 1960, Hurricane Cleo in 1964, and Hurricane Andrew in 1992. Even distant tropical storms, such as Hurricane Sandy in 2012, can cause damage to the park, like harm to facilities on Elliott Key.
On August 24, 1992, Hurricane Andrew made landfall near Miami, passing directly over Biscayne National Park. The storm had maximum sustained winds of 141 miles per hour (227 km/h) and gusts up to 169 mph (272 km/h). The storm surge reached 17 feet (5.2 meters) above sea level. It was a Category 5 hurricane, the strongest on the Saffir-Simpson scale. Hurricane Andrew damaged Biscayne Bay by stirring up the seafloor and making the water cloudy. Mangrove forests along the bay’s edges were also harmed. Fuel from damaged boats and marinas leaked into the bay, polluting it for nearly a month after the storm. A commemorative plaque at the Dante Fascell Visitor Center honors the human and environmental effects of Hurricane Andrew and celebrates the park’s recovery.
The Fowey Rocks light station recorded wind speeds of up to 127 knots (235 km/h) and gusts of 147 knots (272 km/h) before it stopped transmitting, likely due to damage from stronger winds. The most intense part of the hurricane’s eyewall had not yet reached Fowey Rocks when the station stopped working.
Since all park lands are only a few feet above sea level, they are at risk from rising sea levels. Studies by the National Park Service predict that much of the park’s land may be lost over the next 200 years. Sea levels in Biscayne Bay are expected to rise between 3 and 7 inches (8 and 18 cm) by 2030 and between 9 and 24 inches (23 and 61 cm) by 2060. A sea level rise of 3 to 6 inches (8 to 15 cm) could increase saltwater intrusion into the Biscayne Aquifer, an underground water source. Larger rises may turn the southern Everglades into a saltwater marsh, changing the region’s ecosystem.