<P> The Florida Reef ( also known as the Great Florida Reef , Florida reefs , Florida Reef Tract and Florida Keys Reef Tract ) is the only living coral barrier reef in the continental United States . It is the third largest coral barrier reef system in the world ( after the Great Barrier Reef and Belize Barrier Reef ) . It lies a few miles seaward of the Florida Keys , is about 4 miles ( 6 to 7 km ) wide and extends ( along the 20 meter depth contour ) 270 km ( 170 mi ) from Fowey Rocks just east of Soldier Key to just south of the Marquesas Keys . The barrier reef tract forms a great arc , concentric with the Florida Keys , with the northern end , in Biscayne National Park , oriented north - south and the western end , south of the Marquesas Keys , oriented east - west . The rest of the reef outside Biscayne National Park lies within John Pennekamp Coral Reef State Park and the Florida Keys National Marine Sanctuary . Isolated coral patch reefs occur northward from Biscayne National Park as far as Stuart , in Martin County . Coral reefs are also found in Dry Tortugas National Park west of the Marquesas Keys . There are more than 6,000 individual reefs in the system . The reefs are 5,000 to 7,000 years old , having developed since sea levels rose following the Wisconsinan glaciation . </P>
<P> The Florida Reef ( also known as the Great Florida Reef , Florida reefs , Florida Reef Tract and Florida Keys Reef Tract ) is the only living coral barrier reef in the continental United States . It is the third largest coral barrier reef system in the world ( after the Great Barrier Reef and Belize Barrier Reef ) . It lies a few miles seaward of the Florida Keys , is about 4 miles ( 6 to 7 km ) wide and extends ( along the 20 meter depth contour ) 270 km ( 170 mi ) from Fowey Rocks just east of Soldier Key to just south of the Marquesas Keys . The barrier reef tract forms a great arc , concentric with the Florida Keys , with the northern end , in Biscayne National Park , oriented north - south and the western end , south of the Marquesas Keys , oriented east - west . The rest of the reef outside Biscayne National Park lies within John Pennekamp Coral Reef State Park and the Florida Keys National Marine Sanctuary . Isolated coral patch reefs occur northward from Biscayne National Park as far as Stuart , in Martin County . Coral reefs are also found in Dry Tortugas National Park west of the Marquesas Keys . There are more than 6,000 individual reefs in the system . The reefs are 5,000 to 7,000 years old , having developed since sea levels rose following the Wisconsinan glaciation . </P>
where are the coral reefs located in florida
where are the coral reefs located in florida
a few miles seaward of the Florida Keys
a few miles seaward of the Florida Keys