Florida’s Blowing Rocks Preserve: Science and Magic
By Kellilynn Hann
It’s a gorgeous sunny day on Florida’s Atlantic coast. You’re strolling under a shady tunnel of sea grape plants. Their wide leaves rustle and clack and the sun sparkles through, light dancing on the sandy path at your feet. You emerge to a stunning view sand and blue ocean. Once you cross over to the beach, it soon becomes apparent that this is like no other place in Florida.
You’re at Blowing Rocks Preserve, a 73-acre conservation area located just south of Jupiter on Florida’s Treasure Coast. Of the Nature Conservancy’s 400 preserves in the United States, this is their most visited, drawing an average of 55,000 people a year.
The main attraction— a mile-long rock formation right between the sand and sea. If you’ve arrived at high tide and the ocean is choppy, you’ll be treated to plumes of water shooting out of the rock, sometimes up to 50 feet in the air. If you arrive at low tide, you’ll be able to walk along the shoreline, searching all the nooks and crannies for shells, fossils, and that perfect Instagram photo.
But this is just the beginning of the wonders that await you— Blowing Rocks Preserve is full of the beautiful and unexpected.
The Science Behind the Spectacle
The rocks you see here are from the Anastasia Formation. It’s very common in Florida— most of Florida was built on limestone. What’s rare is that so much of it is exposed here.
Dr. Sarah Sheffield, Assistant Professor of Geosciences at the University of South Florida, explained.
“This rock was formed about 2.5 million years ago, during the Pleistocene Epoch when Florida’s sea levels were much higher. When coral reefs break down over millions of years, it builds up and you get carbonate rock (limestone). And that’s what much of Florida is built on,” she said.
The Anastasia Formation is special. “It’s made up of quartz sand and carbonate rock called coquina (which is just a word indicating limestone that’s composed of a bunch of shells mashed together), and it’s only found along the east coast of Florida. You can find it everywhere on the Florida’s east coast, but the rocks are smaller, isolated, broken up, or further inland,” Dr. Sheffield said. “Or, they’re underground or underwater where we can’t see them at all.”
So why is this particular formation at Blowing Rocks more intact and exposed? According to the Nature Conservancy, no one really knows. It’s possible this section was once higher than the surrounding areas or exposed to different conditions.
“The rocks are being weathered down by a bunch of different processes. Chemical processes like weathering caused by rainwater and mechanical processes like wave action,” said Dr. Sheffield. This is what causes the explosive plumes of water you see. As different sections eroded at varying rates, it’s created little tunnels through the rock. When a wave hits hard, the water is forced through the tunnels and shoots into the air at high speeds.
The weathering process also exposes fossils. “You’ll see mostly bivalves (clams) and snail shells, broken up because of the high-energy waves, but sometimes you can find vertebrate or echinoderm fossils.” Dr. Sheffield said. “There are lots of trace fossils, which are evidence of the plant, creature, or its behavior without the actual fossil being present.”
There’s also a big unsolved mystery at Blowing Rocks.
“There are trace fossil burrows here and scientists don’t know what caused them,” said Dr. Sheffield. “There are hypotheses, but nothing certain. It’s fun to study them and imagine what kind of creature might have made them.”
Another surprising fact Dr. Sheffield shared— when you’re standing on the sand at Blowing Rocks Preserve, you’re actually standing on part of the Appalachian Mountains.
“The Appalachians are ancient,” she said, “and they used to extend much further down into what’s now Georgia. So that sand— which can be nearly 150 meters thick in parts of Florida— was transported down from Georgia as parts of the Appalachians weathered to nothing over millions of years.”
Dr. Sheffield said that because of all these forces, Blowing Rocks is changing slowly, every single day, right in front of our eyes. “Just walking around and seeing how 2.5 million years have weathered these rocks out… It’s amazing to know you’re watching the process as it happens. I think it’s absolutely beautiful to think about.”
An Ecological Treasure
While the rocks are certainly the main attraction at Blowing Rocks, there is much more going on here.
The preserve straddles the barrier island with the Atlantic on side and the Indian River Lagoon on the other. It’s also located where temperate and tropical zones intersect. This creates incredibly biodiverse habitats within a small area. As you walk the trails, you’ll see over 250 native plant species like subtropical hardwoods, three types of mangroves, gumbo limbo, wild coffee, Jamacia caper, and sea oats. The preserve is also home to endangered beach peanut and giant wild pine bromeliad.
But the variety of native plant life didn’t come to be this way on its own. According to Blowing Rocks Preserve Manager Cristin Krasco, a lot of time and hard work went into what you see.
“Over a 20-year period, we restored nearly 48 acres of land infested with invasive species to pristine coastal habitat,” Krasco said. “Without these efforts, our native preserve habitats including mangrove swamp, coastal strand, maritime hammock, and beach dune would not be flourishing today.”
Native plants of course mean native animal species can also thrive. “Blowing Rocks Preserve is home to more than 36 imperiled species,” Krasco said. Some of the larger ones you might spot are gopher tortoises, osprey, wood storks, least terns, and West Indian manatee.
But Krasco encourages visitors to keep an eye out for the more elusive critters, too. “Take your time and observe the special habitat that surrounds you— look for our smaller residents such as butterflies, spiders, lizards, and snakes,” she said. You might be surprised by what you discover.
Another key role of the preserve is as a critical nesting site for four species of sea turtles: Loggerhead, Green, Leatherback and Hawksbill. Each year, from March to October, more than 600 sea turtles avoid the light pollution of developed areas and use this dark stretch of beach to lay their eggs. They can lay an average of 100 eggs per clutch and visit multiple times per season. That’s thousands of sea turtles hatching here every year.
The craggy rocks do pose a bit of a challenge to the turtles— both adults and hatchlings can get wedged in the crevices. To solve that problem, The Nature Conservancy manages the Florida Sea Turtle Rescue Program. Every morning during the season, a group of staff and volunteers searches among the rocks to find trapped turtles get them back to the ocean.
“The Nature Conservancy’s protection and continued stewardship of this and other lands provides many benefits to humans and nature,” said Krasco. “We hope that visitors find something that connects them to nature, whether it’s enjoyment of a peaceful walk, a recreational activity such as snorkeling or fishing, a scientific exploration of our diverse plant life, or beachcombing to discover unique shells. Hopefully this connection to nature will lead visitors to develop an appreciation for its benefits and take action to help protect it.”
Planning Your Visit
With all the amazing things to see and do at Blowing Rocks Preserve, it’s a trip that the whole family can enjoy.
Lisa Groisman, travel consultant and owner of Camp Lisa Travels, made a special trip from Miami with her extended family. “You feel like you’re somewhere else—on another planet,” Groisman said. “It’s really beautiful, spectacular. The kids loved climbing the rocks and looking for shells. We stayed two hours, but we could have stayed all day. It’s one of the coolest beaches I’ve ever seen! Get up and go as fast as you can.”
Food and drink are prohibited on the preserve, so plan accordingly. The nearest picnic area and restrooms are a three-minute drive away at Coral Cove park, a mile south of the preserve.
Remember sea turtle nesting season is active March to October; stay away from marked nests, and smooth over any indentations you make in the sand so hatchlings have an easier time getting to the water.
If you need a place to stay nearby, Jupiter Beach Resort & Spa has a private beach, poolside bar, onsite restaurants and spa, and other top-tier amenities. La Quinta Inn by Wyndham and Hampton Inn by Hilton are also close to the preserve.
Blowing Rocks isn’t the only amazing place for nature lovers to explore in the area. Learn more about turtle rescue and conservation at Loggerhead Marinelife Center, and stop by The River Center to enjoy the aquarium, touch tank, and educational displays. Great hiking, paddling, and wildlife spotting can be had at Nathaniel P. Reed Hobe Sound National Wildlife Refuge and Johnathan Dickinson State Park.