Sandfly Island: Everglades Shell Mound Trail

What Sandfly Island Is

Sandfly Island sits in the southern stretch of the Ten Thousand Islands, just off Everglades City and Chokoloskee, inside the Gulf Coast section of Everglades National Park. Like a handful of other high ground in this drowned, roadless country, the island isn't natural bedrock at all — it's built. Centuries of Calusa and earlier Glades-era peoples piled up oyster, whelk and clam shells here as they fished and worked this water, and those shell middens mounded high enough over time to lift solid ground above the surrounding tide flats and mangrove. What grows on that shell terrace today is a dense tropical hardwood hammock — gumbo limbo, buttonwood, wild coffee — rooted in what is essentially an ancient shell heap turned island. From the water it doesn't look like much more than a low, green line of trees; you have to actually land and walk it to feel how different the ground is from the soft mangrove muck surrounding it on every side.

That's what makes Sandfly Island different from most of the spots in our Destinations guide. This isn't a sandbar you beach a boat on and shell for an hour; it's solid ground you actually walk on, with a maintained trail winding through it. It's a rare combination out here — genuine human history and an honest hiking loop, inside a region better known for open water, mangrove tunnels and shifting sand keys.

A Calusa Shell Mound With Homestead Ruins

The shell mound itself predates any of the building traces you'll see on the trail today. Calusa people, and the Glades-culture groups before them, used mounds like this one across the Ten Thousand Islands as elevated, dry footing in a landscape that's mostly tidal creek and mangrove swamp — a place to build a fire, process a catch, and stay above the water. By the time settlers arrived in South Florida, this kind of shell-built high ground was some of the only usable dry land in the region, which is exactly why pioneer homesteaders later cleared parts of Sandfly Island to try farming and living here in the early 1900s. You'll find a similar story at Dismal Key, another overgrown shell mound further out in the islands with its own homestead traces.

Walk the loop today and you'll pass what's left of that chapter — old clearings, scattered foundation stones, and fruit trees gone feral, all being steadily reclaimed by hammock growth. The Park Service leaves it that way on purpose: no reconstruction, no staged exhibit, just overgrown evidence of people who tried to make a life on a shell pile in the middle of the Everglades and mostly lost that fight to the bugs, the heat and the isolation. It's a quietly powerful stop if you like real history over a polished version of it.

Walking the Loop Trail

The trail itself runs roughly a mile in a loop, starting and ending at the small landing where boats and kayaks tie up. It climbs onto the shell terrace almost immediately — you'll feel the ground firm up underfoot — then winds through hammock shade past those old homestead clearings before circling back to the water. There's some interpretive signage along the way, but mostly it's just you, the hammock canopy, and the crunch of shell fragments under your shoes. Songbirds and the odd gopher tortoise burrow turn up along the shadier stretches, and you'll get glimpses of open bay through the trees on the outer leg before the trail ducks back into the hammock. Give yourself 45 minutes to an hour if you want to actually read the signs and look around rather than power through it.

Here's the honest part: the island earns its name. Sandfly Island is called that because of the biting no-see-ums that thrive in the still, shaded hammock air, and they do not take a day off. Bug spray isn't a suggestion here — it's mandatory. Bring real repellent, wear long sleeves if you run hot for bites, and expect the no-see-ums to be worse on calm, humid days with no breeze off the water. There's also no fresh water and no restroom facilities anywhere on the island, so come prepared the way you would for any backcountry stop inside the park.

Getting to Sandfly Island From Everglades City

The jump-off point for Sandfly Island is the Gulf Coast Visitor Center in Everglades City, on the Chokoloskee Bay side of the park. From there it's roughly two and a half miles by water along a marked route — doable by rental canoe or kayak in under an hour of paddling, or considerably faster in a small skiff. It's a genuinely different approach than most of the islands and beaches in our guide, since this one starts at a visitor center with a ranger desk and a water-trail map instead of a private boat launch. Plan around the tide and the clock — give yourself enough daylight for the paddle or run out, the walk, and the trip back, and check current conditions with the visitor center before you head out, since backcountry water levels and marker visibility change with the season.

We'll be straight with you: Sandfly Island is a long haul from Marco Island, and it isn't a stop on our own boat tours, which run the closer-in stretch of the Ten Thousand Islands out of Marco and Goodland. If Sandfly Island is on your list, treat it as its own separate outing tied to Everglades City — pair it with a stop at the visitor center itself and maybe a look at nearby Chokoloskee Island, which sits on its own, much bigger, shell mound and is reachable by causeway rather than by boat. Our Ten Thousand Islands guide lays out how a stop like this fits into planning a full day out here, and if you'd rather stay on the Marco and Goodland side of the map, that's exactly the water our private charters and shelling trips cover every day.