After a bumpy 90-minute drive down a dirt track that cut through dense forest and across rushing streams, I emerged from a pickup truck – next to a cabin that bore the teeth and claw marks of some overzealous grizzly bears. Kluane National Park, I later learned, has the highest concentration of grizzlies in Canada.

Luckily, I was headed for the water. Climbing into a small tin boat, my guide and I rolled out onto Mush Lake. Thirteen kilometres long, ringed by majestic mountains and filled with fish, the lake is the kind of place that would attract weekend warriors, were it located close to any settlement with more than a few hundred inhabitants. “Look around,” the guide, Allan Hansen, told me. “We’re the only people on this whole big lake.”

Kluane National Park is one of the most beautiful and isolated places on Earth. The park is located in the far southwest corner of Canada’s vast Yukon Territory, a place famed for its historic Gold Rush and a territory that's 10 times the size of Switzerland in land area but houses the population of a small town.

Both a Canadian national park and a Unesco World Heritage Site, Kluane’s 22,000sqkm are 80% covered by snow and ice. Much of the rest is temperate rainforest, thanks to the relatively warm waters of the Pacific Ocean lying just to the southwest of Kluane’s boundaries. While mind-bogglingly huge, Kluane (a First Nations word meaning “plentiful fish” and pronounced kloo-wan-ay) is also remarkably accessible, well-connected to a network paved roads, including the Alaska Highway. I was here to experience its best.

As Hansen piloted our little boat past a series of snow-crested peaks, he showed me the survival pack he had thrown on board. “If I die, this bag has everything you need to live,” he said. “Just make a fire, chill out and don’t worry. They’ll come for you from the lodge by nine o’clock.”

Luckily, we both made it to lunch. At one of Hansen’s favourite fishing spots, he offered to give me 30 minutes to catch us a fish before he cast his own line. I got a hit on my very first cast and hauled in a lake trout soon after. “Four minutes – not bad,” he said with a wry smile, looking at his watch.

Within the half hour, I had caught three trout, and we set up on a nearby beach amid a rugged beauty straight from a Jack London novel: red sand, log cabin and fish baking over a crackling fire. As Hansen prepared the meal, I asked if there was anything I could do to help. “Yes,” he said, handing me a blue can of Kokanee beer, a popular Canadian brand. “You can drink this.”

After our fresh lunch of trout, roasted onions and pineapple, we took a short hike, using hip waders to walk into the cold stream that emptied the lake. We were looking for grayling, a breed of fish found only in cold subarctic waters. Hansen showed me a number of different casts, and – as I tried everything from a simple roll cast to a complex double hull – I learned the hard way that fly fishing is more art than science. But the number of fish, and their seeming eagerness to get on my hook, made up for my shortcomings. Sometimes two grayling would jump for the fly. Within an hour or so, I had reeled in some 40 fish; at some point, we lost count.

Kluane also offers about 160km of backcountry trails, ranging from five-day treks to half-hour cakewalks. To experience the most scenic of the park’s non-aquatic attractions, I joined park guide Brent Little for a leisurely stroll.

Little first came to the Yukon in 1975 to help prepare the park for its opening the following year. The park, he told me, is home to the youngest and highest mountains in North America, including the 5,959m-tall Mount Logan, Canada’s tallest peak. Since Kluane lies on a major fault line, the rubbing of the two plates constantly drives the mountains even higher, so they rise at a rate similar to the speed of growing fingernails. “It’s hard to think of terra firma moving at all, but this is a landscape in motion,” Little said.

I got an even better understanding of the landscape’s ongoing formation from the Rock Glacier Trail, with its famed glacier born on the slopes of the nearby Saint Elias Mountains, whose vertiginous peaks towered over us. We pulled into a small lot with just four or five parked cars (“Wow, it’s crazy busy today,” Little said, without a hint of irony). Within 15 minutes, we had hiked along a wooden boardwalk and up an incline, above the tree line, to the rock glacier – a landform created when glacial ice moves loose pieces of stone into a vast area. Walking through a field of boulders, we took in a vista of blue lakes, green forest and snow-capped peaks. “That’s the Dalton Trail,” Little said, pointing. “It was the longest but the lowest of the Klondike routes. During the Gold Rush, prospectors spent five long days on it, from the Pacific Ocean to the Yukon River.”

To truly appreciate both the size and grandeur of the park, Little suggested I see it from above. So I headed to the tiny airstrip in Haines Junction, the closest village to Kluane, and climbed aboard a six-seat Cessna 207 aircraft. As we ascended up over mountains and down into a deep valley, my pilot, Melissa Hough, pointed out Disappointment River. “It was named by depressed miners who got to the Gold Rush too late,” she said.

The sun had just begun to wane. The massive glaciers, which looked like giant tire treads running through the mountains, reflected orange. Soon we were flying over the heart of the park, with nothing but snow and ice below. Mount Logan sat before us on the horizon. Hough pointed out the (invisible) Continental Divide; Pinnacle Peak, which bore an uncanny resemblance to the Matterhorn; and the Kaskawalsh, South Arm and Lowell Glaciers, riddled with crevasses 1km wide at their thickest points.

As we prepared for landing, I marvelled. Here, in this little-known corner of Canada, was one of the largest parks in North America. And I had to explore in three ways – by water, land and air – to even start to fathom its magnitude and magnificence.

Practicalities

Summer (July and August) is the best time to visit Kluane National Park. As it lies in a subarctic climate zone, the season is short, with warm temperatures lasting as little as two months.

Both of Canada’s major carriers – Air Canada and WestJet – fly into the territorial capital, Whitehorse, from Calgary, Edmonton and Vancouver. From there, the park is a two-hour (150 kilometres) drive west along well-maintained roads (including part of the Alaska Highway).

Dalton Trail Lodge is located near the park’s boundary. It provides comfortable accommodations, good meals and some of the most legendary fishing and hiking guides in the Yukon. The lodge also offers a number of fishing and eco-adventure packages.

CORRECTION: A previous version of this article incorrectly stated the size of Kluane National Park. This has been fixed.