(wind howling) (thunder rolling) - In 2011, a bolt of lightning ignited a blaze that burned for 111 days.

(light melodramatic music) This fire was burning through a swamp, the Great Dismal Swamp, which shouldn't be possible.

Even a foot of rain from Hurricane Irene couldn't put that fire out.

- [Newscaster] Another major story of the day of fire that hungers for fuel, it's already swallowed 5,700 acres.

- When it was all said and done, the fire released as much carbon into the atmosphere as a million cars do in a year.

So how did this swamp catch on fire and keep burning for 16 weeks straight?

That question has a pretty alarming answer, and it might change how you see this place forever.

(melodramatic music) (air whooshes) (light water rushing) (light contemplative music) For over 9,000 years, native peoples of this region, the Nansemond, members of the Powhatan Confederacy, and others lived in and around this swamp.

- The fact that this swamp meant a lot to indigenous people across many millennia, they learned that swamp right?

They learned it, and that whole swamp became their home.

- [Joe] Beginning in the 1600s, the Great Dismal Swamp became a place of refuge.

Enslaved people who sought their own freedom, commonly known as maroons, used the swamp's terrain for building permanent settlements.

These were not just hiding spots, they were homes.

They built whole communities here, a hidden society.

- That first generation of enslaved Africans, they would've found indigenous people already there.

And more than likely, these folks, sharing a common purpose, formed communities.

- [Joe] They traded tools and clothing with enslaved workers on the swamp's periphery.

They shared survival knowledge with indigenous communities who had sought refuge here too, thriving in a place the outside world had written off as useless.

(jaunty upbeat music) When colonists came along, they were determined to turn this swamp into dry land.

Beginning in the 1760s, 150 miles of ditches were carved into this landscape.

They were commissioned by someone I think you'll recognize, a young George Washington.

To Washington and other plantation owners, wet land was wasted land.

Couldn't farm it, couldn't make money off of it.

From the mid-1700s to the late 1900s, the swamp was systematically drained to make more farmable land.

The colonists who drained this swamp saw the water as something else they could control, an enemy standing between them and productive land.

- We think that the original Dismal Swamp was about a million acres, and due to construction of the Dismal Swamp Canal, Highway 158, other infrastructure drainage efforts to the remaining Dismal Swamp is about 130,000 acres.

So there's been a pretty radical change in the overall size of the dismal swamp.

(leaves rustling) (light uplifting music) - [Joe] To understand what makes swamps so special, you have to understand what a swamp actually is.

And that answer isn't found in the water, the trees, or the wildlife.

It's what's underneath.

(light uplifting music continues) - Peat is a type of soil that forms from plant material that falls into ponded water.

And that plant material doesn't decompose very rapidly.

It collects and it builds up over time.

So this peat is really fluffy and you see that that auger sinks in very easily, and we hit water very quickly.

This is the upper peat.

This is the highest point that's closest to the ground surface.

It's likely been exposed to the most oxygen and has been degraded the most by being drained.

- [Joe] Peat is the foundation of this ecosystem, and it's one of the most remarkable substances on earth.

This dark, wet acidic soil proves ideal for preserving artifacts of the past and their stories.

- So this is an arrowhead, and so we can also see that it has a kind of a peculiar shape to it.

Okay, so if you can follow my finger tip, that would've been the original edge and that would've had a point that broke off.

In the more recent centuries, somebody found an ancient tool and then they decided, oh, right, I don't need an arrowhead.

What I need is an edge.

So they chipped away and then they used this for some purpose, like scraping or whatever it may be.

This was originally one of these bigger spear points, and it probably broke, and then they used it for a different reason.

- Peat covers only about 3% of Earth's surface, but it stores twice the carbon of all of the world's forests combined.

You heard that right.

More than all of the forests.

(light mellow music) You can think of this swamp as a giant carbon battery.

And it took thousands of years to charge and store up all that carbon.

But, peat only works as a carbon sponge when it's wet.

Drain the water away, and everything changes.

The peat oxidizes and the ancient carbon starts leaking back into the atmosphere.

By 2011, the swamp had been bleeding water for 250 years.

And when peat dries out, just one little spark and... (light dramatic music) (fire crackling) When lit, dry peat can fuel a smoldering mega-fire that's almost impossible to extinguish.

Unlike a surface fire, a peat fire burns underground, creeping through the soil itself, sometimes meters below the surface.

It produces dense, toxic smoke and can reignite weeks after appearing to go out.

Fires in 2011 and 2008 together released roughly 6.2 million metric tons of CO2.

But once a swamp like this is dried out, the question is whether it's climate-changing power can be restored.

This swamp is now part of a national wildlife refuge and a North Carolina State Park, and the people who run them are trying to bring that water back.

Historically, the Great Dismal Swamp sequestered massive amounts of carbon in the ground, but then drainage and fires turned it into a net source of carbon overall.

And that's what they're working to reverse.

If draining the swamp caused the problem, fixing it means doing the opposite.

The peat needs water again to lock carbon safely underground and make it far less likely to burn.

So how do you undrain a swamp?

Well, first you need to figure out how to stop the drainage.

- It's kind of like a sieve.

If you wanna hold water, if you gotta plug all of the holes, you can't just plug one of them.

(water trickling) We refer to these generally as water control structures.

And this is a weir-type water control structure.

In the center of the ditch, we've lowered that sheet pile to create these openings in the weir that allow water to pass through it.

And it's in these openings we had boards, two by six boards.

And so this structure is how we slow drainage in the swamp, hold the water level in the ditches higher, and then re-wet the peat.

(light melodramatic music) - [Joe] Since the refuge opened 50 years ago, 75 water control structures have been installed across the 150 miles of ditches.

From up here, the scars of history are still visible.

150 miles of man's misguided attempt to control nature, and to control the spirits of other men.

- And what maroons represented, right, and were, were people who had had enough of slavery and they find new places to form communities with like-minded and like-activated people.

They were using whatever they could find in the swamp itself to help them survive and thrive.

Ancient artifacts, right, as we might call 'em today, they were in the soils already, right, from the people that lived there long before the maroons and indigenous people of the modern times.

So yeah, it's a hugely important part of global history, African Diaspora history, Indigenous American history.

- [Joe] Archeology can tell us what people left behind.

It can't always tell us who they were.

For that, we need a different kind of witness.

- I'm a descendant of Moses Grandy from Camden County, North Carolina, (mellow guitar music) and he was known and famous for having a slave narrative published about his life in 1843.

He was born to a family that was enslaved, but he always had the intestinal fortitude to work to be free.

It was something that he had in his spirit.

- [Joe] Grandy hauled timber from the swamp's interior, carrying it to surrounding towns where it was used for building.

Every trip, every load, he was earning money toward the one thing he wanted.

- He worked until he could earn enough money for his freedom.

The first time, he bought his freedom for $600, which was a lot of money in those days.

If these trees could talk, it could tell me about the pain that people felt being here.

The hopelessness, the physical pain, the mental pain, the spiritual pain, actually how people endured.

The Dismal Swap represents freedom and it also represents death at the same time 'cause a lot of of our ancestors died out here and were never recognized.

So we honor them today.

We don't know their names, but we know their bones are still in this swamp.

- Slowly, the life of this place is being restored.

Once you stop the drainage, the swamp can start refilling itself.

(water rushing) (light uplifting music) The water source, though, isn't a river or a reservoir.

It comes from the 50 inches of rain that this ecosystem receives each year.

The same rain that's always fallen here is now, at long last, being allowed to stay.

(bird chirping) Restoring a swamp isn't as simple as turning the water back on.

Once peatlands have been damaged, they don't hold water the way that they used to, which means even when you try to re-wet them, they can still dry out.

And there are trade-offs.

The same roads that dry out parts of the swamp are also the roads firefighters rely on to reach these fires.

They're also how visitors get in.

- Yeah, I think my work in some of these wetland systems has made it really clear that restoration is a work in progress.

- Restoring the Great Dismal Swamp is a climate intervention.

A way to draw down carbon, a wildfire prevention program, but it's also an act of rejuvenation.

The restoration project is already working.

The peat is rewetting, less carbon is leaking out.

The risk of another peat fire is dropping and the swamp is returning to its historic glory, a place for not just animals, but that people have relied on for thousands of years.

- We were able to accomplish a lot.

We were able to plug up all the ditches in the most densely drained parts of the refuge.

- It's not an easy effort, but thanks to this restoration, it's estimated that these peat wetlands suck up and store about 200,000 metric tons of carbon per year, offsetting the emissions from around 42,000 cars.

- We've improved hydrologic conditions across, roughly half of the refuge is our estimate, and I'm proud of that.

I'm proud that we were able to accomplish that.

- Places like the Great Dismal Swamp are places of inspiration.

They are, in and of themselves, restorative.

They harbor creatures that can't live elsewhere.

Organisms that we depend on and that we draw a certain level of a greater understanding of the whole that we are a part of by spending time in a place like this.

(light uplifting music continues) (light uplifting music continues)