Once a mining hub, the US's newest national park is a thrilling playground.

The steady rumble of traffic passing overhead is so loud that I can close my eyes and imagine I'm in a Brooklyn loft. But the urban reverie shatters the minute I open them and see my legs dangling 250 metres above a foaming mass of white water. Fortunately, I'm strapped securely to the underside of the third-highest (and almost certainly prettiest) bridge in the United States.

"Back in the day, it took 45 minutes to get from one side of the gorge to the other," Paul Storey tells me. "But when the bridge opened, that went down to less than a minute." The garrulous 77-year-old is guiding us on the New River Bridge Walk, which has allowed guests to traverse the gantry beneath this handsome single arch bridge since 2011. Storey was one of just six guides back then, but after West Virginia's New River Gorge was declared a national park in 2020, visitor numbers surged. Today, 30 guides lead some 200,000 people a year along the underside of the 920-metre bridge.

Despite its name, West Virginia's New River has been cutting a path through the centre of the Appalachian Mountains for 250 million years. But it wasn't until the 350-metre deep gorge created by "The New" became the USA's newest National Park that it stepped onto the global stage.

The hidden hollows and foothills of Appalachia have long been renowned for their natural beauty, and West Virginia's state motto ("Almost Heaven") was inspired by John Denver's ode to the region's backroads. But without the protections offered by the park (which was previously designated a National River), this would be a vastly different landscape.

West Virginia has long been the centre of America's coal mining industry, and by the turn of the 20th century there were more than 60 coal mining towns spread out along the banks of the New River and its tributaries. Together with loggers, they stripped the land bare and when the bridge opened in 1977, Storey recalls, "This was all industrial; there were no trees at all."

Despite this destructive history, the land flourished once it was given protected status, and today the jade green river is flanked by thick forests of oak, maple and beech that are home to a healthy population of bears, deer, coyotes and river otters.

Though several days is enough to see most of the park's highlights, the abundance of outdoor adventures on offer means that I could easily extend my stay to a few weeks. "I came here because of the sheer variety of activities," says Haynes Mansfield, who works at ACE Adventure Resort.

"It's unrivalled; you just can't find this many things in such a small space anywhere else. You can put in from our property for world-class whitewater rafting, there's incredible mountain biking and rock climbing, and enough hiking trails to keep you busy for months."

Once I've taken in the views from the New River Bridge, I explore the park on foot and soon discover why the aptly named Endless Wall trail is among the park's most popular paths. After passing through a forest of rhododendrons, I emerge at the edge of a sandstone wall that plummets down to the river. From there, the majority of the 3.8-kilometre trail follows a natural balcony that serves as one extended lookout, connecting countless rock platforms that jut out into the abyss to offer incredible views both up and down the gorge.