KEY LARGO, Florida Keys - Free admission to John Pennekamp Coral Reef State Park is available Saturday, Dec. 11, during a special 50th birthday celebration planned for that day.

The golden anniversary of the park at mile marker 102.5 on the Florida Keys Overseas Highway offers a variety of events beginning at 9 a.m. the culmination of 12 days of events in Key Largo honoring America's first undersea preserve.

Scheduled activities include an Environmental Expo featuring ecological and historical exhibits, oral histories shared by past park managers and staff as well as a featured keynote presentation by Dr. Sylvia Earle, a renowned oceanographer and Time magazine's first "Hero for the Planet."

Souvenir anniversary medallions and lapel pins are to be available while supplies last, as well as posters of an underwater scene, created for the park's 50th by artist Wyland.

Slated for the expo are some 40 organizations representing Florida Keys and national conservation groups including the Coral Restoration Foundation, The Dolphin Research Center, The Turtle Hospital, Florida Keys national wildlife refuges, Florida Keys Overseas Heritage Trail, The Nature Conservancy, History of Diving Museum, National Parks and Conservation Association, the Florida Park Service and the Wyland Foundation Youth Ambassadors for the Planet.

Visitors also can enjoy the park's popular water activities -- at regular concession prices -- including viewing the reef on glass-bottom-boat or snorkel and scuba tours, as well as canoeing and kayaking on mangrove-lined waterways.

A visitor center featuring a refurbished 30,000-gallon aquarium, as well as nature trails, picnic pavilions and two beaches round out the variety of offerings at Pennekamp.

More details are at www.fla-keys.com/pennekamp50 . Key Largo visitor and accommodations' information is at www.fla-keys.com/keylargoor 1-800-822-1088.