The islands of the refuge contain mostly mangrove habitat, although of primary importance to some species are a few beaches and salt ponds. Red mangrove forests constitute all or part of the vegetation on most of the islands. More than 250 avian species have been recorded in the refuges in the lower Florida Keys including Great White Heron National Wildlife Refuge and National Key Deer Refuge.
In addition to providing nesting habitat for a variety of birds, the refuges provide important loafing and feeding areas for magnificent frigates, migrant shorebirds, terns, raptors, and waterfowl like the red-breasted merganser. Extensive beaches are found on a few islands and are an imperative habitat for shore birds and nesting endangered Atlantic green, Loggerhead, and Hawksbill sea turtles.
Salt ponds, impounded from open water by storm created berms, are a particularly important habitat for piping plovers, terns, stilts, and a variety of wading birds, including reddish egrets. In addition to sea turtles, the indigenous mangrove terrapin is another notable reptile using the refuge.
With the exception of portions of a couple islands, the refuge beaches are open to public access for wildlife-dependent activities such as wildlife observation and personal photography. Closed areas are clearly marked. The refuge is only accessible by boat. Jet propelled personal watercraft, seaplane landings, water-skiing, airboats, and hovercraft are prohibited as per an agreement between the United States Fish and Wildlife Service and the State of Florida in 1992.
The Key West National Wildlife Refuge offers a visitor center on the mainland introducing and outlining visitation of the refuge islands. Paddling, nature photography and wildlife viewing opportunities are supreme. Certain areas are off-limits to visitors. These are usually wildlife nesting areas. Sea kayaking is a favorite area recreation offering a relaxing way to explore some of Florida's most pristine reaches. Outfitters dot US 1 providing guides along with gear necessary to reach the backcountry of the Keys. Excursions take the visitor to shallow flats where creatures such as spiny lobsters, stone crabs, barracudas, stingrays, and sea stars may be observed. The abundant birdlife is particularly enjoyed through a good pair of binoculars. Snorkeling and scuba diving are very popular recreations as well; rental gear is offered through private outfitters.
The Key West National Wildlife Refuge is an area of water and land stretching 25 miles west of the resort town of Key West. The refuge encompasses the "Lakes" and the "Marquesas." Boat access only. Watch for restrictive signage.