Home to 84 protected species of plants and animals, Dagny Johnson Key Largo Hammock Botanical State Park shelters one of the largest remaining tracts of West Indian tropical hardwood hammock in the United States. Once slated for condominium development, this 2,500-acre ecological treasure was rescued in the 1980s and now serves as a crucial habitat for endangered species like the American crocodile, Key Largo woodrat, and Key Largo cotton mouse.
Park Overview: A Tropical Paradise Preserved
The lush tropical hammock canopy provides shade along the park’s trails
Dagny Johnson Key Largo Hammock Botanical State Park stands as a testament to successful conservation efforts in the Florida Keys. Named after local environmentalist Dagny Johnson, this botanical wonderland was saved from becoming Port Bougainville, a massive development that would have included 15 hotels and over 2,000 condominiums.
Today, the park protects a rare ecosystem that botanists call “the land of little giants” – a reference to the many National Champion trees that grow here. Despite their champion status, none of these remarkable trees exceed 45 feet (13.7 m) in height, creating a uniquely accessible canopy forest experience.
Quick Facts: The park features over 6 miles (9.7 km) of trails, most of which are paved and accessible to both bicycles and wheelchairs. The entrance fee is $2.50 per person, payable at an honor box (exact change required).
Best Time to Visit & Weather Tips
Early morning offers cooler temperatures and beautiful light for photography
The park is open 365 days a year from sunrise to sunset, but timing your visit strategically can greatly enhance your experience. The Florida Keys have a tropical climate with distinct wet and dry seasons.
Recommended Months
- November to April – Dry season with pleasant temperatures (21-27°C/70-80°F), low humidity, and minimal rainfall
- Early morning visits – Arrive at sunrise for cooler temperatures and active wildlife
- Weekdays – For a more solitary experience with fewer visitors
Months to Avoid
- June to September – Hurricane season with high humidity, frequent afternoon thunderstorms, and extreme mosquito activity
- Summer afternoons – Temperatures can exceed 32°C (90°F) with oppressive humidity
- Holiday weekends – The nearby attractions in Key Largo can create traffic congestion
Important Note: Unlike most of the Florida Keys, this botanical state park does NOT receive mosquito control spraying. During summer months, insect repellent is absolutely essential, and even in winter, it’s recommended.
Getting There & Planning Your Journey
Dagny Johnson Key Largo Hammock Botanical State Park is located at County Road 905, Mile Marker 106, Key Largo, FL 33037
Located in the northern part of Key Largo, Dagny Johnson Key Largo Hammock Botanical State Park is easily accessible by car. The park entrance is situated on County Road 905, approximately 0.5 miles (0.8 km) north of its intersection with US Highway 1 at Mile Marker 106.
Plan Your Trip to Key Largo
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Transportation Options
By Car
From Miami: Take US-1 South for approximately 1 hour and 15 minutes (about 60 miles/97 km). Look for Mile Marker 106 and turn north onto CR 905.
From Key West: Follow US-1 North for about 2 hours and 30 minutes (approximately 100 miles/161 km) to Mile Marker 106.
By Public Transit
Limited options are available. The closest public bus stop is at MM 106 on US-1, requiring a short walk to the park entrance.
Consider using rideshare services like Uber or Lyft for the final leg if you don’t have a car.
Nearby Airports
Miami International Airport (MIA): 65 miles (105 km) north
Key West International Airport (EYW): 100 miles (161 km) south
Both airports offer rental car services for the drive to Key Largo.
Things to Do: Trails, Wildlife & Activities
The paved Port Bougainville Trail is accessible for hikers, cyclists, and wheelchair users
Despite its relatively compact size, Dagny Johnson Key Largo Hammock Botanical State Park offers several engaging activities for nature enthusiasts. The park’s main attractions revolve around its unique ecosystem and the rare species that call it home.
Hiking Trails
Port Bougainville Trail
Length: 2.4 km (1.5 miles) loop
Difficulty: Easy
Features: Paved path following old development roads, accessible for wheelchairs and bicycles. Passes through dense hammock forest with interpretive signs.
Key Largo Hammock Nature Trail
Length: 1.1 km (0.7 miles)
Difficulty: Easy
Features: Self-guided interpretive trail with educational signs identifying tropical plant species, including several National Champion trees.
Wild Tamarind Trail
Length: 3.2 km (2 miles) round trip
Difficulty: Easy to moderate
Features: Less traveled path showcasing some of the park’s champion trees, including the wild tamarind. Offers glimpses of the park’s interior hammock.
Wildlife Viewing
The white-crowned pigeon is one of the park’s more commonly spotted endangered species
While many of the park’s endangered species are elusive, patient visitors may be rewarded with wildlife sightings. The best times for wildlife viewing are early morning and late afternoon when temperatures are cooler and animals are more active.
- Birds: White-crowned pigeons, mangrove cuckoos, and various migratory species
- Reptiles: American crocodiles (rare), various lizards and snakes
- Mammals: Key Largo woodrat and Key Largo cotton mouse (both endangered and rarely seen)
- Invertebrates: Colorful liguus tree snails, butterflies, and various insects
Explore Guided Tours & Activities
Enhance your visit with expert-led tours of the Florida Keys’ natural wonders. From guided nature walks to kayaking adventures in nearby waters.
Botanical Highlights: National Champion Trees
The park is home to several National Champion trees, recognized for being the largest of their species
What makes Dagny Johnson Key Largo Hammock Botanical State Park truly special is its concentration of National Champion trees – more champions in one location than anywhere else in the United States. Remarkably, none of these champions exceed 45 feet (13.7 m) in height, earning the park its nickname: “The Land of Little Giants.”
| Tree Species | Common Name | Notable Features | Champion Status |
| Lysiloma latisiliquum | Wild Tamarind | Feathery leaves, twisted trunk | Current National Champion |
| Guaiacum sanctum | Lignum Vitae | Blue flowers, extremely dense wood | Former National Champion |
| Canella winterana | Wild Cinnamon | Aromatic bark, red flowers | Current National Champion |
| Guapira discolor | Blolly | Leathery leaves, small fruits | Current National Champion |
| Gymnanthes lucida | Crabwood | Glossy leaves, three-lobed fruits | Current National Champion |
Safety Warning: The park contains poisonwood and manchineel trees, both of which can cause severe skin reactions similar to poison ivy but potentially more serious. Stay on designated paths and avoid touching any plants unless you can positively identify them as safe.
Practical Visitor Tips
The park operates on an honor system for entrance fees – bring exact change
What to Bring
- Water (at least 1 liter/person)
- Insect repellent (essential year-round)
- Sunscreen and hat
- Comfortable walking shoes
- Binoculars for wildlife viewing
- Camera for botanical photography
- Exact change for entrance fee ($2.50/person)
Park Facilities
- Composting toilets near the entrance
- Small picnic area
- Interpretive signage
- Paved and unpaved trails
- Honor box for fee payment
- No drinking water available
- No food services or gift shop
Rules & Etiquette
- Stay on designated trails
- Pets allowed on leash
- No collecting plants or animals
- No smoking on trails
- Pack out all trash
- Bicycles permitted on paved trails
- No camping or overnight stays
Visitor Comments About Dagny Johnson Key Largo Hammock Botanical State Park
Nearby Attractions
John Pennekamp Coral Reef State Park offers world-class snorkeling just minutes from Dagny Johnson Key Largo Hammock
While Dagny Johnson Key Largo Hammock Botanical State Park is worth a visit on its own, its location in the Upper Keys puts it within easy reach of several other outstanding natural attractions. Consider combining your visit with these nearby destinations:
John Pennekamp Coral Reef State Park
Distance: 5 km (3 miles)
Highlights: America’s first underwater park featuring spectacular coral reefs, glass-bottom boat tours, snorkeling, and diving opportunities.
Why Combine: Experience both the terrestrial and marine ecosystems of the Florida Keys in one day.
Crocodile Lake National Wildlife Refuge
Distance: Adjacent to the park
Highlights: Protected habitat for the American crocodile and other endangered species. Limited public access, but visitor center provides information.
Why Combine: Learn about complementary conservation efforts in the Upper Keys.
Florida Keys Overseas Heritage Trail
Distance: Access points throughout Key Largo
Highlights: 106-mile (171 km) trail following the historic Overseas Railroad route, perfect for cycling, walking, and fishing.
Why Combine: Extend your outdoor adventure with scenic views of both the Atlantic Ocean and Florida Bay.
Extend Your Florida Keys Adventure
Make the most of your trip to the Florida Keys by exploring the region’s unique attractions by land and sea.
Experience the Natural Wonders of Key Largo
The park is open from sunrise to sunset, offering beautiful lighting conditions for nature photography
Dagny Johnson Key Largo Hammock Botanical State Park offers a unique opportunity to experience one of Florida’s most precious and endangered ecosystems. While it may lack the flashy appeal of coral reefs or white sand beaches, this botanical treasure provides something equally valuable: a glimpse into the natural history of the Florida Keys before development transformed the archipelago.
From its collection of National Champion trees to its role in protecting endangered species, the park stands as a testament to successful conservation efforts. Whether you’re a passionate botanist, a casual nature lover, or simply looking for a peaceful walk in a unique setting, this hidden gem of the Upper Keys deserves a place on your Florida itinerary.
Ready to Explore Dagny Johnson Key Largo Hammock?
Plan your visit today and discover the natural beauty of the Florida Keys’ tropical hammock ecosystem.
The above is subject to change.
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