Blue Hole is a small lake and former limestone quarry in the National Key Deer Refuge on Big Pine Key. A short, shaded trail leads to an observation platform above the water, where alligators, birds, fish and Key deer may be seen. Kiosks explain the local wildlife, and the quiet setting makes this a useful nature stop on a drive through the Florida Keys. The lake is not especially blue, despite its name, and wildlife sightings are not guaranteed.
A quarry turned wildlife habitat
Blue Hole began as a limestone quarry. Rock taken from the site was used for local roads and construction connected with Henry Flagler’s Overseas Railroad. The excavation left an open basin that filled with water, creating a lake in an area where freshwater is scarce.
The lake’s water has layers: freshwater sits above saltwater that seeps in from below. This unusual habitat draws wildlife to the water’s edge. Blue Hole is described as the largest freshwater body in the Florida Keys, though the lake itself is small.
What you may see around the lake
The observation platform gives you a place to look across the water for alligators. They are often spotted near the platform, but sightings depend on the day. Keep a respectful distance and observe from the trail or viewing area.
Key deer, an endangered deer found only in the Florida Keys, also live in the refuge. Birds, including wading birds, as well as fish, turtles, snakes and iguanas are among the animals associated with the lake. Some visitors have seen small tarpon in the water. Bring binoculars if you want a closer look without approaching wildlife.
Walking the trail
The walk from the parking area is short and shaded, with information kiosks along the route. The path to the observation platform includes a paved section that has been described as suitable for wheelchairs and strollers. A covered pavilion, benches and binoculars are available near the viewing area.
A gravel trail continues around toward the other side of the lake and ends at a wooden gate. The walk is a modest outing rather than a long hike, and the combination of shade and interpretive signs can work well for families with young children. For more walking, Manillo and Watson trails are nearby.
Planning a wildlife stop
Early morning and late afternoon are suggested times to look for animals. Still, wildlife is not guaranteed: some visits bring sightings of alligators, deer and birds, while others are quiet. Weather can also affect animal activity, so check conditions before setting out.
Blue Hole is on Big Pine Key, within the National Key Deer Refuge. It makes a brief nature stop during a drive through the Keys, especially if you want a break from the shoreline and a chance to learn about the island’s wildlife. The name can set an expectation of bright blue water, but the lake may not look blue.
FAQ
Where is Blue Hole?
Blue Hole is in the National Key Deer Refuge on Big Pine Key, Florida.
Can you see alligators at Blue Hole?
Alligators live at the lake and are often seen from the observation platform, but sightings are not guaranteed. Use the platform to watch from a distance.
How long do you need at Blue Hole?
Allow about 30 to 60 minutes for the short trail, lake views and information kiosks.
Is the Blue Hole trail accessible?
The route to the observation platform includes a paved section described as suitable for wheelchairs and strollers. The trail beyond the platform is gravel.
