Florida Reef
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 lies a few miles seaward of the Florida Keys, is about 4 miles (6 to 7 km) wide and extends along the 20-metre (66 ft) depth contour 270 km (146 nmi; 168 mi) from Fowey Rocks just east of Soldier Key to just south of the Marquesas Keys.