Fort Jefferson, Coral Reefs, and Sea Turtles in the Gulf of Mexico
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Fort Jefferson, Coral Reefs, and Sea Turtles in the Gulf of Mexico
Dry Tortugas National Park sits at the far end of the Florida Keys chain, about 70 miles west of Key West in the Gulf of Mexico, accessible only by ferry or seaplane. It is one of the most unusual and remotely situated parks in the national park system: 100 square miles of sea surrounding seven small islands, 99 percent of which is open water. The park is named for the sea turtles spotted there by Juan Ponce de Leon in 1513 and for the absence of fresh water that made the islands dangerous to sailors. Those sailors still found them strategic enough to justify the most improbable construction project in American military history.
Fort Jefferson, on Garden Key, is the park’s centerpiece and one of the most remarkable structures in the United States. Construction began in 1846 and continued for decades, eventually consuming more than 16 million bricks in a hexagonal sea fortress rising 50 feet above the turquoise water. It is the largest brick masonry structure in the Western Hemisphere, and it was never finished. The Civil War disrupted the project, yellow fever decimated the garrison in 1867, and fears that the weight of the fort would sink Garden Key underwater ultimately suspended construction entirely. Walking the ramparts and moat walk today, surrounded by open sea in every direction, is an experience unlike anything else in the national park system.
Below the fort, the reef and surrounding waters are equally extraordinary. The Dry Tortugas sit above one of the world’s most productive and least-disturbed coral reef systems. Snorkeling directly from the Garden Key beach puts swimmers over sea turtle habitat, colorful reef fish, coral formations, and occasionally nurse sharks resting on the sandy bottom. Scuba divers have access to historic shipwrecks in the surrounding waters. The park is the only tropical reef in the continental United States.
May and June bring one of the most spectacular bird events in the eastern United States: thousands of sooty terns and other seabirds return to nest on nearby Bush Key, visible from Garden Key. More than 299 bird species have been documented in the park, and spring brings migrating warblers, tanagers, and other songbirds resting on the fort walls after crossing the Gulf of Mexico.
Most visitors access the park via the high-speed catamaran ferry Yankee Freedom III from Key West, a roughly two-hour crossing with an arrival at approximately 10:15 a.m. and departure at 3 p.m. Key West offers the most complete range of accommodations, from luxury historic inns to pet-friendly condos and vacation rentals with beautiful waterfront views, hot tubs, and easy access to the ferry terminal. Overnight camping in the park’s primitive Garden Key campground is available, but requires a reservation with ferry ticket purchase.
Check nps.gov/drto for current permits and ferry schedule. Book your accommodations for Dry Tortugas National Park.
Seasons
Mild and less crowded; ideal for snorkeling, hiking, birdwatching, sea turtles, wildflowers
Warm and clear, ideal for swimming, snorkeling, diving, longer daylight for wildlife viewing and exploring Fort Jefferson
Slightly cooler, fewer crowds, great for bird migration and snorkeling. Warm days and cooler evenings.
Serene and tranquil; cooler temps, clear skies, calm seas. Great for snorkeling, turtle and bird viewing.
Top 3 Facts about Dry Tortugas National Park
Fort Jefferson, built beginning in 1846 on Garden Key, is the largest brick masonry structure in the Western Hemisphere, constructed from more than 16 million bricks. The fort was never completed; construction was halted by the Civil War, yellow fever, and structural concerns. During and after the Civil War, it served as a military prison, most famously housing Dr. Samuel Mudd, convicted for treating John Wilkes Booth.
Dry Tortugas National Park sits above a coral reef system considered to be the third-largest in the world and the only tropical reef in the continental United States. The park’s waters are protected as a Research Natural Area and are designated as part of the Florida Keys National Marine Sanctuary. Snorkeling from the Garden Key beach provides direct access to this extraordinarily rich reef habitat.
More than 299 bird species have been documented at Dry Tortugas National Park. The islands sit on the Atlantic Flyway migration corridor, and spring migration brings exhausted warblers, tanagers, and other songbirds that land on the fort walls after crossing the Gulf of Mexico. From May through September, Bush Key hosts one of the largest sooty tern nesting colonies in North America.
Travel Tips
Plan Ahead
Reserve Yankee Freedom III ferry tickets well in advance, particularly for spring bird migration season and summer weekends. The ferry departs from the Key West ferry terminal and allows approximately 4.5 hours at Garden Key. Overnight campers must reserve the ferry and campsite simultaneously, limited to 10 campers per ferry. Seaplane access from Key West Seaplane Adventures offers a faster alternative. Book at nps.gov/drto.
Pack Appropriately
Bring all food, water, and supplies needed for your visit; no food services are available inside the park. Pack reef-safe waterproof sunscreen, a snorkel mask, and fins for the reef. Bring sturdy sandals or water shoes for the beach and moat walk. A light jacket is useful on the open ferry crossing. There are no cell towers in the park. Carry cash for any on-site concessions at the ferry.
Respect Wildlife
Sea turtles nest on Garden Key beaches from April through October; do not approach, disturb, or shine lights on nesting turtles. Keep the minimum required distance from all wildlife including nesting seabirds. Do not stand on, break, or touch coral reef formations while snorkeling. Bush Key is closed to all public access from February through September to protect the nesting tern colony. Pack out all trash from the campground and beach.
Stay Informed
Check nps.gov/drto for current park conditions, ferry schedules, campsite availability, and any hurricane or tropical weather closures before visiting. The park is subject to closure with minimal notice during hurricane season from June through November. Monitor National Hurricane Center forecasts. Contact the park at 305-242-7700 for current conditions and emergency information.
- Area (mi²)
- 101
- Annual visitors
- 79 200
- Established year
- 1992
Accessibility & permits
Emergency
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Frequently Asked Questions
Ready to dive into what Dry Tortugas National Park has to offer? Let’s tackle some of the burning questions you might have as you plan your visit!
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You should stay in Key West, as it is the closest city to the park and offers various lodging options, since there is no lodging within the park boundaries. Key West is located at the end of the Overseas Highway and provides all necessary visitor services.
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There are no child-friendly hiking trails since 99% of the park is underwater, and the only walkable area is a loop around Garden Key where Fort Jefferson is located. This loop is more of a walk than a hike. Other activities like snorkeling, exploring the fort, and observing wildlife are more prominent.
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Pets are not allowed inside Fort Jefferson. Only service dogs are permitted, but they must be individually trained to assist a person with a disability. Other pets can only be on Garden Key and must be on a leash.
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You can park your vehicle at the City Parking Garage on Grinnell Street in Key West, which is across the street from the Yankee Freedom Ferry Terminal. The garage offers shaded parking for $40 per day. There is no free parking available in the area.
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The top attraction is Fort Jefferson, a massive six-sided fort built from 1846 to 1875 using 16 million handmade red bricks. It was constructed to protect the southern coastline of the United States and the strategic deepwater anchorage in the Dry Tortugas. The fort was never fully completed or attacked but played a crucial role in U.S. military history.