The Canadian Rockies Traverse No One Had Finished—Until Now

When Adam Mertens set out before dawn on August 30, the Banff athlete knew he was attempting something no one had done before: a continuous, human-powered loop around the Bow Valley skyline. The line stretched 146 kilometers across ridges, summits, cliffs, and river crossings stitched together into what he now calls the Bow Valley Cirque.

Over three days, Mertens would run, climb, scramble, paddleboard, and crawl across 11,000 vertical meters of mountain terrain. He slept only six hours in total. He clipped into ropes for 5.10 pitches, tiptoed across knife-edge ridges, rappelled through loose rock, and threaded descents so exposed he later admitted, “I hope to never have to do it again.”

Seventy hours and 20 minutes after leaving Johnson Lake, he returned to the same spot, closing a loop that had haunted him for a year.

“It had the makings of a really good goal,” Mertens told ExplorersWeb. “The outcome wasn’t guaranteed. There was going to be compounding fatigue, moments of wanting to quit, and you’re always in view of your house, with all the comforts right there. That makes it uniquely hard.”

The birth of an idea

The Bow Valley Cirque did not come from an official race or guiding company. It emerged from the same late-night map sessions that fuel much of the Rockies’ endurance culture.

“Over our long winters, runners pore over maps and dream up outlandish ideas,” Mertens said. “Most of those ideas stay there. But some take hold.”

Years ago, he floated the notion of linking the Rundle Traverse, a 25-kilometer ridgeline classic, with the mountains across the valley. The idea hardened when friend and fellow runner Reuben Driedger asked in 2023 whether anyone had ever completed a full skyline circuit.

By spring 2024, Mertens had traced a route on a map: a giant horseshoe around Canmore and Banff, touching the summits of Cascade, Rundle, Ha Ling, the Three Sisters, Grotto, Lady MacDonald, Girouard, Inglismaldie, and more. It would require climbing, endurance running, and alpine decision-making in equal measure.

He tried it that summer and fell short, exiting early at Carrot Creek. The unfinished line stuck in his head all winter.

“I love setting big goals for myself,” he said. “It felt worthwhile to circle back to this one.”

Section by section, peak by peak

Mertens divided the loop into six sections, each expected to take 10 to 14 hours. Two per day, with minimal sleep. He cached water and climbing gear around the valley in the week prior to lighten his load.

Day 1: Cascade and Rundle.

At 2 a.m. on August 30, Mertens jogged into the darkness toward Cascade Mountain. With a partner, he tackled the east ridge, a 5.10 route requiring ropes and simul-climbing. They topped out at sunrise, an hour faster than the previous year.

From there, he descended into Banff and began the Rundle Traverse, 25 kilometers of class 4 and 5 scrambling with rappels and a summit at 2,948 meters. By 6 p.m. he stood on Rundle’s main peak, then pushed east along the serrated ridge until fatigue forced him to sleep three hours at Whiteman’s Pond.

Day 2: Ha Ling, Lawrence Grassi, the Sisters, Wind Ridge, Grotto.

Back on his feet by 4 a.m., he and a friend simul-climbed the northeast face of Ha Ling, a technical route bolted for protection. Sunrise greeted them at the summit. He continued across Mount Lawrence Grassi and into the Three Sisters, navigating exposed downclimbs on Big Sister before running solo along Rim Wall, which he later called “the most intimidating part of the whole circuit.”

By mid-afternoon, he was high-fiving friends atop Wind Ridge. From there, he paddled across the Bow River and launched into Grotto’s east ridge, summiting near midnight. Another three hours of sleep followed.

Day 3: Lady Mac, Stewart, Pechee, Girouard, Inglismaldie.

With a lighter pack and sore legs, Mertens scrambled Lady MacDonald’s knife-edge ridge at sunrise, sharing the moment with a small group of friends. He passed Charles Stewart and reached Carrot Creek by midday, the place he had quit the year before.

Ahead loomed the unknown: Pechee, Girouard, and Inglismaldie. At Girouard, the difficulty spiked. Guidebooks listed the ridge as “4th class,” but Mertens and his partner found themselves on crumbling ledges above a 1,500-meter drop, forced to rappel from a sketchy anchor.

“It was the point where I really questioned whether it was worth it,” he said. “I felt I had crossed my threshold of acceptable risk.” Then lightning crackled around them, hair buzzing. They escaped unscathed, but the scare lingered.

By 9 p.m., Mertens stood atop Inglismaldie. Three hours later, he jogged back into Johnson Lake, where the loop began.

Training for the impossible

Despite the climbing cruxes, Mertens insists the Bow Valley Cirque was “still very much an endurance running challenge.” He trained by stacking back-to-back 30-kilometer mountain runs with 2,000 meters of gain, mimicking the fatigue of consecutive days.

He also rehearsed technical sections repeatedly. By the time of his attempt, he had completed the Rundle Traverse 11 times, Ha Ling’s northeast face a dozen times, and most other sections at least three.

“While the climbing grades might be considered low, the consequences are very high,” he said. “I strongly advocate that anyone considering even sections of this route carry proper gear, seek mentorship, and understand what they are getting into.”

Balancing ambition and risk

Risk was never abstract. On Girouard, it became visceral. Loose rock, poor protection, and incoming weather forced decisions under pressure.

Mertens later reflected on the “heuristic traps,” the psychological shortcuts that lead mountaineers astray. He admitted the finish line being so close influenced his judgment. “I had very publicly shared this goal with my community, and felt a degree of accountability to reach the end this time around.”

He emphasized that the traverse was not about reckless bravado. “I know that sharing my adventure opens me up to criticism,” he said. “I want people to situate it within a respectful approach to mountain adventures that might inform their own decision making.”

Unlike some athletes who chronicle every move for an online audience, Mertens has never seemed interested in cultivating clout. Scroll through his social media accounts and you will find plenty of mountain photos, but not the kind of swaggering captions or glorified risk-taking that often fuel viral fame. He is, if anything, unassuming online, a runner and climber who happens to test himself in audacious ways rather than someone trying to build a brand around them.

A community effort

Though solo at times, Mertens leaned heavily on his community. Friends joined him for major sections. Others stashed supplies, filmed, or simply appeared at obscure trailheads to cheer.

“Completing this traverse would not have been possible without incredible support,” he said. “The Canmore running community is exceptional.”

That support extended into town. As Mertens scrambled ridge lines, drivers sat in Labor Day weekend traffic jams on the valley floor. “While I’m dancing around on ridge tops, other people are navigating long weekend traffic,” he said with a laugh.

One of those supporters was local filmmaker Philip Alexander, who followed the attempt with his camera. Alexander had attended the Banff Mountain Film Festival the year before and left inspired to try making a documentary of his own. He saw Mertens as the perfect subject.

“Adam was at the top of my list, and as soon as I asked if he’d be up for it, he was in,” Alexander said. The project quickly turned into a collaborative effort: Adam self-shot segments on action cameras in places no filmmaker could safely follow, while Alexander captured what he could from accessible ridges and trailheads.

His plan is to submit the finished film to the Banff Mountain Film Festival in 2026, a fitting stage for a story rooted in the Bow Valley. “It would be amazing to have Adam’s achievement celebrated there and to share it with the local community in such an iconic setting,” Alexander said.

One and done

Now 32, Mertens calls the Bow Valley Cirque his “perfect backyard adventure.” He has no plans to repeat it. “This route was a one-and-done effort,” he said. “But I’ll definitely repeat certain sections.”

For him, the reward was not just finishing. It was the experiment itself: seeing if such a line was possible, and discovering where the edge of safety and endurance lies.

“It was about testing the limits in my own backyard,” he said. “Not because it was the biggest or the hardest, but because it was ours.”