Travel and adventure photographers Renee and Matthew Hahnel set off on the ultimate road trip in 2017 with a mission to visit every national park in the US. Their new book, Roaming America (Lannoo Publishers), follows their seven-month adventure and paints an inspiring portrait of the country's varied landscapes. Here we reveal the 15 parks that they ranked as the most beautiful and why...

Starting at the Grand Canyon and ending in American Samoa, their journey took them to every single one of America's 59 national parks. On this incredible seven-month trip, mostly done in a trusty 1988 Westfalia Vanagon, the couple clocked up over 25,000 miles (40,000km) as they travelled across 39 states, to two US territories, took 26 flights and walked along countless hiking trails.

“We kept a rating scale throughout our national parks journey, ranking each park for its scenery, trails, facilities, crowds, and how photogenic it was,” write the couple. They selected 15 standout parks as the most scenic. “These are the parks that ranked the highest for scenery... These parks [also] typically ranked the highest for hiking trails, and they were often also the most photogenic.” Some are well-trodden, others barely known. Take a look...

Colorado’s magnificent mountainous national park was where the pair’s love affair with America’s great natural wildernesses all started. They relocated from their native Australia to live in Boulder, Colorado. “Rocky Mountain National Park was our first local park when we relocated to America, and where our love for the outdoors was truly engrained. Being back on our favourite trails feels nostalgic and we make an effort to soak in every moment,” they write.

With seemingly endless peaks to explore, the park is a veritable adventure playground with incredible hiking, camping, wildlife and views. Its most famous route is the Trail Ridge Road, the highest paved road in any of the country's national parks at more than 12,000 feet above sea level. Prepare for hairpin bends, steep drops, dazzling views and plenty of other traffic in summer. Keep watch for elk and bighorn sheep, of which there are many. The park is also a prime prowling ground for bears and mountain lions.

Set on south-central Alaska’s Kenai Peninsula, it may be the state’s smallest national park but Kenai Fjords delivers immense beauty with its fjords, coves, rugged headlands and glaciers. The Harding Icefield is the park’s most striking feature and can be seen on the steep Harding Icefield trail. “We reach the top and are blown away by the view, for before us lies a horizon of ice and snow that stretches as far as we can see,” write the Hahnels.

The wild coastal park is an important habitat for an array of creatures: moose, black bears, wolverines and coyotes roam among its forests, myriad marine birds come here to fish and nest while its waters teem with marine mammals including harbour seals, Steller sea lions, and sea otters. One unbeatable way to see the fjords and glaciers is on a scenic flight from Seward. You can also kayak around to explore the fjords' hidden bays and ski the icefields in winter.

This beauty of an Alaskan national park is vast with seemingly endless glaciers, rivers and snowy peaks. “There is nothing small about this magnificent park, and its beauty will imprint on any person that steps within its boundaries,” write the couple. In fact, it's the largest national park in the country and – when combined with neighbouring parks – comprises the world’s largest international protected wilderness.

The Hahnels hiked up to Root Glacier on their visit, one of the remote park’s most awe-inspiring features with its startling blue ice and pool, and frozen canyons. “Careful not to trek near any crevasses, we hike until eventually finding the bluest glacier pool either of us have ever seen. What an incredible sight to behold!” You can also go ice-climbing with a guide. Other musts are a tour of the Kennecott Mines National Historic Landmark to learn about the area’s copper mining history.

Named after the majestic Mount Denali, which at 20,320 feet (6,194m) is the highest mountain in the US, this park beckons adventurous travellers with its backcountry trails and remote campsites. “Its glacial covered summit is absolutely stunning and especially so when you get closer into the park. Denali is also home to some insane wildlife – we saw brown bear, moose, caribou, elk and much more,” say the couple.

The two-mile loop trail alongside Denali's Savage River is one of the park’s easier trails. To delve into remoter parts of this extraordinary wilderness, it pays to sign up to a ranger-guided hike – they’ll teach you about the park’s fascinating flora and fauna, geology and cultural history. Or hop aboard a tundra wilderness tour to get up close to some of Denali’s wildlife (Dall sheep, moose, grizzly bears, caribou, coyotes and wolves are likely sightings).

Dominated by its eponymous active volcano, Mount Rainier National Park serves up dreamy landscapes all year round. But summer is really special, when wildflowers carpet the meadows below the snow-capped peak. “The view of Mount Rainier towering above us never becomes unremarkable,” write the couple. “We hike through meadows filled with wildflowers, through forests of thick pines, and by the refreshing spray of waterfalls. It’s a busy park, yet we continually find ourselves on lesser-known trails, soaking in the magnificent views.”

The park is made up of five areas – Paradise, Sunrise, Longmire, Ohanapecosh, and Carbon/Mowich – which circle the mount. Paradise is the most popular section – being nearest to Seattle and home to some of the park’s most renowned trails. Tipsoo Lake (pictured) near the summit of Chinook Pass is a great spot to enjoy the wildflowers or head off on one of the park’s many hikes. The Hahnels recommend the following: the Skyline Trail Loop, Mt. Fremont Lookout Trail, and Tolmie Peak Trail.

It might be one of the country’s best known beauty spots but Yosemite has plenty of off-the-beaten path adventures and hidden gems. The Hahnels recommend heading to backcountry trails in Tuolumne Meadows and Mariposa Grove to avoid the crowds. On their trip, however, they had their eyes on one of Yosemite's most famous landmarks – the Half Dome. “Our muscles burn and feet slip as we traverse the worn granite of Half Dome’s final ascent. All the pain is instantly forgotten when we stand at the summit to breathtaking views over the Yosemite Valley and beyond,” they write.

The couple, who visited the park in September, were also struck by the view from Cathedral Lakes in the Tuolumne Meadows area. “The view from the lakes after a fresh snowstorm was our favourite site during this visit to Yosemite. We’d previously visited this area in spring, so seeing it in such different conditions was amazing,” they say. You can see the spectacular high sierra Upper and Lower Cathedral lakes by following a seven-mile loop trail from the Cathedral Lakes trailhead.

A haven for hikers and outdoor adventurers, this epic national park with its canyons, rivers and waterfalls leaves a lasting impression with its raw beauty. At its centre is the deep and narrow Zion Canyon. There are trails around and inside its red-cliffed gorges, including one into The Narrows, its slightest section. “The view from inside The Narrows is still one of my favourites in the US. Walking through the water and looking up at those huge, vibrant sandstone walls feels like something from another world,” says Renee.

The park is laced with hiking trails for enjoying the grandeur of the scorched landscape – if you’re looking for a strenuous but highly rewarding route set off to Angels Landing via West Rim Trail (pictured). It's one of the best known trails and deservedly so with its sweeping views over the gaping canyon. The couple also recommend the hikes to Observation Point and the Subway trails.

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Only accessible by air, this patch of pristine marine wilderness in Alaska’s southeast is well worth the effort. It's famous for its glaciers – both alpine and several incredible tidewater glaciers, which are best seen by boat or on a kayak excursion. “The whole of Glacier Bay is absolutely gorgeous,” says Renee. “Those glaciers are absolutely huge, and the diverse wildlife in the area is really cool to see from the water on a boat or kayak.” Flight-seeing trips from nearby Juneau are also highly recommended. 

As well as snowy peaks, glacial lakes and deep fjords, the diverse park also has rainforests. Head off on a kayaking tour from Bartlett Cove to follow pretty river trails into the rainforest – you could see seals, porpoise, sea otter, black bear, moose, and bald eagles as you paddle. Or venture out into the Icy Strait, just outside of Glacier Bay National Park, on a whale-watching excursion to spy orcas and minke whales.

The Hahnels say they had the best experience of their whole trip in another off-the-beaten-track patch of Alaska, Lake Clark National Park. “We stayed in a remote cabin right on the most turquoise coloured lake you could imagine. For three days we were alone, there was no one else around and it was silent other than the water softly kissing the shoreline of the lake. There were mountains surrounding us on every side, and we foraged for berries to put in pancakes, caught and cooked lake trout, and paddled the canoe to hike from different parts of the lake,” says Matthew.

Once again, you’ll need to catch a plane or boat trip to access this far-removed land of blue glaciers, winding rivers and snowy peaks. But that just means you’ll largely have the trail-free wilderness to yourself. Lake Clark, a 50-mile-long turquoise lake, is at the park's centre – stay in a lodge or you can largely set up camp where you like. Visit in summer and you’ll be dazzled by the incredible variety of wildflowers that carpet its surrounding meadows and hills.

Set on the border between northwest Montana and Alberta in Canada, the grandeur of the park’s many glaciers, vast valleys and towering granite peaks never fails to astound. “We’ve visited Glacier National Park on many occasions now and ever since our first visit it has been one of our favourites,” say the Hahnels. “There are so many beautiful mountains in that area, and so many gorgeous lakes to go to watch the sun set or rise. There are also a lot of moose, elk, bear, mountain goats and big-horn sheep in the area, so if you want to see wildlife this is a great spot for it."

Hiking trails lace the park, which also has one of the country’s most famous scenic drives: the Going-to-the-Sun Road. Travel along its 53 miles (85km) to strike a route through the heart of this spellbinding landscape. You’ll pass glassy lakes and forest-clad peaks, and gaze down on dramatic gorges and flower-strewn valleys. Get your camera ready for Logan Pass, the highest part of the drive with dizzying views, and to capture the wildlife.

Brown bears and big fish are the prime reasons to visit this protected area in southern Alaska’s scenic Katmai National Park. Every July and August, thousands of the beautiful but deadly creatures congregate to gorge on sockeye salmon at Brooks River. It’s an incredible sight to behold. The couple picked the park as one of the most scenic due to the wildlife. “Due to the incredible infrastructure they have built there, you can view them from an incredibly close distance while still being safe. The mountains around the area are also stunning!” they say.

Set on the Alaska Peninsula, most people arrive on a floatplane to explore this great wilderness. It’s a bucket-list destination for keen anglers with its lakes home to five species of Pacific salmon as well as rainbow trout, and Arctic char. While rafting and kayaking around the chain of lakes and rivers known as the Savonoski Loop and hiking around the spectacular Valley of Ten Thousand Smokes also promise epic views and thrills aplenty.

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Located within the Brooks Range, the most northern mountain range in north America, this park is as remote as they come with no man-made trails or buildings whatsoever. When asked which national park of all 59 they visited they’d most like to photograph again, Renee and Matthew agree it would be this one. “We had to pack light on our backpacking/pack rafting trip and left our bigger cameras behind. It would be great to go in again with some more gear and really explore deeper into the valleys,” they say. 

This true and rugged wilderness is only accessible by plane, foot or boat. But those that make it enter an ethereal world that is untouched by humankind. Rafting trips along the wild rivers promise staggering views and a sense of real adventure. As do hikes around the famed Arrigetch Peaks with their plunging valleys, and jagged granite spires. “The peaks are some of the most dramatic on the planet, and the high alpine lakes we came across were the most intense shades of blue you could imagine!” they say. 

Famed for its high peaks and geothermal features, Yellowstone is the world’s first national park and home to some of America’s most spectacular nature spots. The world-famous Old Faithful is the pinnacle for most people visiting the park, including the Hahnels. They recall hiking along the Upper Geyser Basin Trail to watch the geyser erupt at sunset. “Every corner brings another vibrant geothermal pool, bubbling mud pit, or steaming geyser.”

Set in the Rocky Mountains on the border of Wyoming and Montana, the park's many peaks, meadows, forests, and rivers are also home to an incredible variety of wild animals. Yellowstone is famed for its large population of bison, as well as elk, bighorn sheep, moose, deer and coyotes, bears and wolves, which were reintroduced in the 1990s. The Lamar River Trail is a good one to appreciate the park’s varied terrain and intriguing inhabitants.

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“Everything is lush and vibrant green in this magnificent rainforest, and each turn brings another canopy of surprises," write the travel photographers about Washington State's Olympic National Park. "The forest floor is thickly blanketed with moss and ferns. The best way to describe it would be enchanting.” Plenty of trails lace around the park's tangle of ancient temperate rainforests and edge along its wild Pacific coastline, which is punctuated by sea stacks. 

Another of the Olympic Peninsula's most striking landmarks is Lake Crescent, a deep body of water renowned for its beautiful blue waters and bounty of fish. Rent a boat or take the plunge into its refreshing waters – if they're too chilly there are hot springs nearby. The summit of the park's eponymous glacier-clad Mt Olympus is popular with climbers. While the pair point to the Hoh Rain Forest, Sol Duc Falls and Ruby Beach as their top scenic photography spots. 

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With spectacular snow-capped granite peaks, lakes, rivers and wildlife, Wyoming’s Grand Teton National Park delivers dramatic beauty in spades. “Grand Teton ended up as the number one spot on our list due to its combination of extreme beauty and accessibility. With the town of Jackson so close, you can head out for the day, see some of the most beautiful landscapes on earth, and be back in town for a delicious meal by dinner,” say the couple.

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Named after its tallest peak, the Grand Teton (13,770 feet/4,197m), this stretch of wilderness in America's Rockies is made for hiking. One of the Hahnels' favourite hikes was the 15-mile Cascade Canyon trail to Lake Solitude and back. The deservedly popular route strikes through some of the park’s most stunning scenery, along rocky, rugged and steep terrain at times. The end views of the glacially-carved lake are otherworldly. Be vigilant for bears, and keep watch for beavers, otters, and moose as you explore. 

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