It is connected to the island of Key West by the Fleming Key Bridge (Mustin Road), having 18 feet (5.5 m) of clearance over Fleming Key Cut, a small channel.
The island and bridge road are part of a section of the Naval Air Station Key West called Trumbo Point and are inaccessible to civilians without US Navy clearance. The island has a 10 million gallon per day wastewater treatment plant. It also includes a dolphin research center and marine corrosion testing facility.
The United States Army Special Forces Underwater Operations Training Center is located at the far northern tip of Fleming Key.