The power of the Calusa people stretched from Sarasota to Miami to the Florida Keys.

But their capital was right here in Southwest Florida: Mound Key.

It was a gleaming, white island of immense proportion that people would have known about and talked about.

We hike what remains of this engineered city on the Gulf Coast, where the Calusa fought off colonial threats to their homeland.

If I wanted to go back in time, I'd want to go back a day in the life of a Calusa with the Spaniards here, right?

Mound Key in Estero Bay is rich with history and archaeological mystery.

How did the Calusa manipulate their environment to not only survive, but thrive?

What stories are embedded on this island?

Over centuries, the Calusa people used leftover shells to create and shape Mound Key.

The island was home to an estimated 1000 people and the Calusa capital when Spanish colonizers arrived in the 1500s.

In more recent decades, there's been fascinating research that helps decode the imprint the Calusa left.

But to visit this one-of-a-kind island, we'll need a boat.

I began this chapter of our journey in Bonita Springs, the Gulf on one side, estuary on the other.

Not a bad view.

We met Mound Key enthusiast Nancy Kilmartin at the docks.

How much time have I spent out there?

Oh, I can't, I couldn't even tell you.

Hundreds of hours.

It would take us less than an hour to get to Mound Key.

Our destination sits behind barrier islands of the Gulf.

It's a few miles from the Mound House on Fort Myers Beach, once the site of a Calusa village.

The Calusa lived along Southwest Florida's coast for almost 2000 years.

The estuary surrounding Mound Key is home to Florida's finest sea life, a habitat for manatees and dolphins.

A rotating cast of birds joined our trip through the mangroves.

Were actually in the middle of Estero Bay, and that's Mound Key.

We're looking at it from the south-- I was glad to have Nancy there.

It can be hard to differentiate Mound Key from other keys in the bay.

She helped us find a hidden cove leading to the landing.

All right, we made it!

We made it!

This landing, when the Calusa inhabited this island, this landing was not their access point.

They went up through the central canal, which we'll see in a little bit.

We were looking at a part of the island that had been destroyed by 20th century pioneers who saw opportunity in what the Calusa left behind.

This area was actually, there was two different excavations conducted, and they excavated the shell out and they used it for road fill.

So you might be driving over Calusa artifacts when you drive on U.S.

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Mound Key is more than 100 acres.

Its managed by nearby Koreshan State Park, where Nancy worked as a ranger.

The public trail is less than a mile and crosses the island, passing remnants of two important mounds and a canal constructed by the Calusa.

What you're seeing here is a lot of crushed shell, because people have been walking on it over the years on this particular trail.

But this presumably was left over from the Calusa.

Oh, absolutely, absolutely.

It was hard to reconcile that my sneakers were touching the traces of an ancient city.

Nancy spotted something even more amazing right off the path.

So this is a piece of pottery that's Calusa.

It's called sand-tempered plain, and it's really a lot of what the island is made out of is discarded tools, discarded tableware, discarded pots, obviously discarded food products, the shell and the fish bones.

It is illegal to take anything off the island.

Over the years, the site was looted and illegally excavated.

Today, access is limited to the trail.

The first mound we visited has a rich history, spanning from the Indigenous Calusa to more modern pioneers.

In the late 1800s, Frank and Molly Johnson settled on the island to farm.

It's been said that Molly Johnson tried to protect the archaeological assets, sometimes with a shotgun.

And yet she was also known for her generosity.

Locals called her Grandma Johnson.

She helped teach arriving families how to survive.

Why would homesteaders choose to live here?

Probably the same reason the Calusa did.

It's beautiful.

You're in the middle of Estero Bay.

They had a school out here, and there was multiple families who lived out here.

Molly Johnson moved off the island in her later years.

Most other residents left after brutal hurricanes in the 1920s destroyed homes throughout South Florida, including on Mound Key.

By the 1960s, the state owned most of the island.

The mound where homesteaders once lived also contained clues to 16th century history.

Fieldwork by archaeologists and students uncovered Spanish artifacts and evidence of structural remains.

The research confirmed that the mound was the site of a Spanish fort, as well as a mission to try to convert the Calusa to Christianity.

But the Calusa had their own belief system.

The relationship descended into violence within a few years.

The Calusa abandoned Mound Key, as did the Spanish.

By the early 1600s, the Calusa reestablished their Mound Key capital.

Later that century, another set of missionaries arrived.

They lasted a matter of weeks.

There's a story where the Calusa took the friars, the Franciscan friars, and stripped them of their clothes and marooned them out on Key West, out on the Keys.

They're like, we've had enough of you.

Get off, get off, get off our island.

The next stop on our agenda was the Grand Canal.

Though today it looks more like a ditch, it was once a maritime highway crossing the island.

My theory is that you could probably navigate to this island because of the, because of the smell.

I mean, dead fish, dead, you know, fish, shellfish.

Who knows what it smelled like?

Perhaps the Calusa grew nose-blind because fishing was central to their lives.

Historically, societies that relied on fishing rather than farming were assumed to be less advanced.

That's far from true of the Calusa people.

The Calusa were highly intelligent.

They were great engineers, great engineers.

I know that much, and they were smart enough to elevate where they lived, so that the floods came, hurricanes come.

They were elevating.

Their power extended beyond construction.

Archaeologists consider the Calusa among the most politically complex groups of hunter-gatherers in the ancient world.

Their population may have reached 20,000 people across Southwest Florida.

Discarded shells were the bedrock of their kingdom of islands and canals.

The Calusa built up Mound Key, engineering the island with essentially their trash.

Food waste.

At first glance, it just looks like a beautiful circular thing from space, but it, it was designed with purpose.

It's remarkable what the Calusa did with that island.

They chose well for their capital.

Mound Key is close to the resources of the Estero River and the Gulf, with some storm protection from the barrier islands.

What do they say today in the real estate industry?

Location, location, location.

This was an ideal location.

With productive oyster reefs nearby.

It can't be more than a five-minute paddle, and you can collect oysters and you've got a meal.

I don't think the archaeologists like this all that much, but I'm going to say it anyway.

For me, it was like, in my, in my view, it was like the ramen noodles or the or the macaroni and cheese for the Calusa, right?

It was a cheap and easy meal.

Was always there.

Oyster shells were also the foundation of so-called watercourts, landscape features that had long intrigued scientists.

Savarese was part of a team that decoded some of their mystery.

The site researchers studied sits near the bay.

But a fence blocked our path.

Though we couldn't get close, Calusa scholars did.

The team included distinguished archaeologists like Victor Thompson of the University of Georgia, and Karen Walker and Bill Marquardt from the University of Florida.

Scientists and students looked for clues about how the watercourts actually worked.

Using remote sensing technology, sampling and excavations.

After years of study, they concluded that the watercourts were feats of sophisticated engineering.

Complex, walled structures of shells and other sediment that allowed for fish trapping and storage.

We believe that they, at least on the short run, were able to trap fish, but also to store them there until they could process them.

We found evidence of of fish processing, of roasting or smoking fish.

The huge structures were engineered with a deep understanding of the tides and fish behavior, reflecting a long history of Indigenous engineering in Southwest Florida.

Their building of the interlock systems for the fish to have them come in during high tide and then close it off and just wait for low tide... You know, somebody had to think of that.

Calusa.

The large-scale fish traps and storage system may have done more than feed the Calusa people.

Their rulers could have leveraged the surplus using fish as an instrument of soft power.

When you're in a position to offer resources to people who don't have as many resources as they need, you're in a position to exert influence over them, to draw tribute or taxation from them.

This is patronage clientage if you will.

It's, but it's not necessarily that somebody comes in and conquers you.

Their research also showed that the Calusa elite may have enjoyed direct access to the bounty.

Archaeologists found paths leading from the watercourt area to the mound summits.

The most mullet fish remains were found behind the Kings Mound, the island's peak.

That's where Nancy Kilmartin and I headed next.

So we're at the top.

We're at the top.

And we are about 33 feet above sea level.

Just like most people who, you know, are in power, they want to go up.

And I can imagine standing here without the vegetation, maybe seeing three Spanish galleons coming by.

When Spanish colonizers landed in the 1500s, this was the seat of Calusa power.

The Calusa people resisted the Spanish for two centuries.

Historical accounts from that period are not from the Calusa perspective.

Spanish descriptions, repeated for centuries, often characterized the Calusa as violent.

Archaeologist Bill Marquardt challenges that simplified view.

I don't see them as warlike people.

I see them as people trying to defend their way of life.

We hear the same kind of things today.

You know, you you, it's easy to cast a, an accusation at someone, a group of people who you don't like, or don't want or you want to get rid of.

The Calusa ultimately lost the battle for Southwest Florida.

The once-mighty kingdom collapsed in the 1700s as its people were decimated by European diseases, slave raids, and displacement.

Today, there's no singular Calusa culture anymore.

It's, It's been melted into Seminole, Miccosukee.

So there's still remnants of it.

And a lot of, a lot of the knowledge that they had, they passed on to us.

Mound Key is a monument to Indigenous ingenuity, an island strategically designed with shells to support a complex society using the resources of the sea.

A physical link between our experience and ancient history.

We finished our hike near the bay.

Nancy often feels the bond of place and history on this island.

She's volunteered for several archaeological digs here.

Once, she found what was likely an ancient shell tool.

The last person who touched it was a Calusa.

Not this shell specifically, but.

And how does that make you feel?

As someone who's interested in in the history.

It's just a really cool connection.

I mean, it's just...you just feel connected.

Youre connected, connected to your history, connected to your backyard.

So, yeah.

Fun stuff.

Support for this program was provided by the Lee County Visitor & Convention Bureau, and Howard K. and Nancy B. Cohen.