Congaree National Park

Listen for a moment. Beneath the canopy here, the air feels heavy and still. Water drips from a leaf somewhere above you. A woodpecker knocks on a dead trunk, and the sound carries a long way through the trees. Underfoot, the boardwalk creaks softly. The light reaches the forest floor in pale green patches, filtered through layer after layer of leaves. This is Congaree National Park, in the river lowlands of central South Carolina, a short drive from the state capital, Columbia.

Many visitors arrive expecting a swamp. That is what people called this place for decades, and you will still hear the word. But Congaree is not really a swamp. It is a floodplain forest. Swamps hold standing water most of the year. Here, the rivers rise and spill into the forest several times a year, then drain away again. That rhythm of flood and retreat shapes everything you see around you — the soil, the trees, and the animals that live among them.

What makes this place special is age. Congaree protects the largest intact area of old-growth bottomland hardwood forest left in the southeastern United States. Bottomland simply means low, flat land beside a river. Forests like this once covered huge stretches of the American South. Over the nineteenth and twentieth centuries, most of them were cut for timber or cleared for farming. Here, a large block survived. Walking this boardwalk, you are moving through something that has almost disappeared from the region.

Now look up. Some of the trees around you rank among the tallest in eastern North America. Loblolly pines, sweetgums, cherrybark oaks and others grow to enormous heights in this rich, wet soil. Several individual trees here have been recognised as state or national champions for their species, meaning they are the largest known examples. It can be hard to judge their scale from below. Try standing beside a trunk and tilting your head all the way back. The crown often vanishes into the canopy above.

Then look down, especially near the water. Those strange knobs rising from the mud are cypress knees. They grow up from the roots of bald cypress trees, which thrive in wet ground. Some look like small stone figures, others like wooden candles. Scientists still debate exactly what purpose they serve. Some think they help anchor the tree in soft soil. Others have suggested they help the roots breathe. Nobody has settled the question, which is a quiet reminder of how much this forest still keeps to itself.

Here is a detail many visitors walk past. Look closely at the trunks around you. On many of them you can see a faint line of dried mud or discoloured bark, sometimes well above your head. That line marks how high the last flood reached. When the Congaree River overflows, it carries nutrients and fresh sediment into the forest. That yearly delivery of rich mud is one reason the trees here grow so large. The floods are not damage. They are food.

It is worth asking how this forest survived when so many others did not. In the late nineteenth century, a timber company acquired much of this land. Some logging did take place, and you can still find old stumps if you know where to look. But the wet ground, the frequent floods and the difficulty of moving heavy logs out of the lowland made large-scale cutting hard. Much of the forest stayed standing, almost by accident, for decades.

By the middle of the twentieth century, that protection by accident was running out. Rising timber prices made logging the remaining old trees attractive again. A local newspaperman named Harry Hampton spent years writing and campaigning to save the forest. Later, a grassroots movement of residents, conservationists and students joined the effort. In 1976, the land was protected as a national monument. In 2003, it became a national park. The visitor centre carries Hampton's name today.

The forest also holds human stories that are easy to miss. For generations before the park existed, this floodplain was a working landscape. People hunted, fished, grazed cattle and ran small logging operations here. Historians also note that the dense lowlands of the region offered refuge to people escaping slavery, who sometimes lived hidden in places like this. Very few traces remain on the surface. But the remoteness that protected these trees once protected people, too.

Now, a lighter note — and a practical one. Inside the visitor centre, you may spot a sign known as the mosquito meter. It rates the current mosquito level on a playful scale, from mild to something much more alarming. It is a joke, but it is also honest advice. In the warm, wet months, mosquitoes here can be intense. The cooler months, from late autumn into early spring, are often far more comfortable for walking.

One event draws people from far away each year. For a short period around late spring, the park becomes home to synchronous fireflies. Thousands of these small insects flash their lights in waves, more or less together, in the darkness of the forest. Only a few places in North America are known for this display. Because it has become so popular, the park sometimes manages access to the viewing nights, so it is worth checking ahead if you hope to see it.

As you walk, keep your ears open. The forest is full of sound if you slow down. Barred owls are common here, and they often call during the day. Their call is a series of hoots that birders describe with the phrase, who cooks for you, who cooks for you all. Woodpeckers are everywhere, including the large pileated woodpecker with its red crest. Frogs fill the evenings in warm weather. You might also hear something crashing through the undergrowth — very often a deer, or a wild hog.

If you have more time, there are other ways to meet this place. Hiking trails lead away from the boardwalk and deeper into the floodplain. Cedar Creek winds slowly through the forest, and paddling it by canoe or kayak gives you a view at water level, among the cypress trunks. Conditions change quickly after rain, and some trails flood. Rangers at the visitor centre can tell you what is open and passable on the day you visit.

Before you leave, pause once more on the boardwalk. Notice how quiet it has become while you were listening. The trunks around you have stood through floods, droughts, storms and the arrival of the people who nearly cut them down. Some will still be standing long after today. As you walk back toward the car park, watch the light shift between the leaves, and listen for the knock of a woodpecker somewhere behind you, still at work in the old forest.