Massive Rockfall Reshapes Mountain Near Canmore. Climbers Warn More Could Fall.

A slab of rock estimated at 200 metres tall broke off Windtower’s north face on Sept. 29, taking with it the bottom portions of two climbing routes, including one that Calgary-area climber Raphael Slawinski spent two decades completing.

Despite losing much of the route, Slawinski says he feels more relief than heartbreak.

In an Oct. 5 Instagram post, Kananaskis Mountain Rescue shared a current photo alongside one from 2024, which together show a significant change to the face, including a large overhanging “roof” across much of the slope.

“There are no designated hiking trails in the affected area, and this post is being shared for local awareness,” the post said. “As conditions may continue to change, with additional rockfall possible, visitors are encouraged to avoid the immediate area and use caution when travelling nearby.”

The face is visible from the Trans-Canada Highway. The hiking route to Windtower’s summit, which starts from the West Wind Pass trailhead on Spray Lakes Road, should be unaffected, according to Rhys Beaudry, executive director at Climb Alberta.

The rockfall is the latest of several on the face in recent years. A smaller one in 2024 broke away just right of one of the now-destroyed routes, according to the climbing website Mountain Project.

Amanda Regnier, a Calgary running coach, was hiking neighbouring Wind Ridge that day. She was turning back one or two kilometres below the summit because of incoming weather when, at about 12:15 p.m., she heard what she thought was thunder. She turned to see a dust cloud rising off Windtower and caught it on video.

“For a split second, [it was] a little bit nerve-wracking because you wonder how much of the rock is going to fall... you’ve heard things like Frank Slide,” Regnier said. “You just feel so small, and there’s nothing you can do but just stand there.”

The face is about 450 metres tall and overhangs from bottom to top, Slawinski said. Mark Carlson, a local route developer who bolted one of the affected routes, estimated in an Instagram comment that the slab measured about 200 metres by 50 metres and was four to five metres thick.

Slawinski said there have been several major rockfalls on the face in recent years, “but nothing as big as” this one.

“The scale of this latest rockfall was quite shocking,” he said.

The area has not been reported as officially closed, but climbers warn that the newly exposed rock could continue shedding smaller pieces for years.

“Probably the rock under it is really, really bad and will continue to shed some amount of smaller rock for years as water and weather hits it,” Beaudry said. “I think that probably the pair of rockfall incidents on Windtower will be enough that no one’s going to go there for a long time.”

Two Climbing Routes Damaged

Three completed routes and one unfinished line climb the north face. Another route, Le Jour Le Plus Long, is on a separate face to the east and was unaffected, Slawinski said.

Iron Butterfly, first climbed in 1988 by Jeff Marshall and Steve DeMaio, appears to be intact. The route is climbed mostly by pulling on climbing gear rather than on the rock itself (a style called aid climbing), and it has never been repeated.

Slawinski’s route, Daddy Longlegs, is 14 pitches long. A pitch is one rope-length section of a climb. Based on photos a climbing partner took from Wind Ridge and his own view from the highway, Slawinski estimates the first seven or eight pitches are gone.

The 36th Chamber of the Windtower, a 15-pitch route Carlson bolted to the right of Daddy Longlegs, also lost its lower half. Carlson told Beaudry what had changed.

“Mark said all three crux pitches fell off for sure, plus the six below are demolished,” Beaudry said. A crux is the hardest section of a climb.

Carlson did not respond to a request for comment.

Slawinski has seen parts of the face fall before, including a leaning pillar beside his route that came down in the last few years.

“I was not surprised when this pillar fell off, but this is kind of shocking and just kind of makes you realize that you never know,” he said.

After years of on-and-off work on Daddy Longlegs, Slawinski says he feels relief rather than grief.

“I don’t really care about it as some kind of a monument... It’s not like I’m heartbroken that it’s gone. More than anything, given the number of days I spent up there, I think it’s almost a feeling of relief that I was not in the wrong place at the wrong time,” Slawinski said. “The odds that I would have been up there on the very day when it happened were low, but not zero.”

A Route 20 Years In The Making

The route began as DeMaio’s vision for a second line up the face. In 2002, he recruited two young climbers, Slawinski and Eric Dumerac, to attempt it. They planned to climb straight through, hauling gear and food and sleeping in a portaledge, a hanging tent. By midday on the second day, they had reached their high point and turned back.

“We could manage climbing on crumbling holds and exfoliating flakes, but hauling the massive bags crushed our bodies and spirits. We rappelled off and walked away,” Slawinski wrote in a 2023 account of the route for the Canadian Alpine Journal.

In the years that followed, he put Windtower out of his mind, focusing on alpine climbing in the Rockies and expeditions to Alaska and the Karakoram range in Asia. His 2013 first ascent of K6 West in Pakistan with Ian Welsted earned them a Piolet d’Or, one of mountaineering’s top international awards.

He returned to the route in earnest in the late 2010s, working on it with Alik Berg, and began climbing it with Danny Poceta in 2021. By then, rockfall was already reshaping the face.

On their first trip together, Slawinski led the scrappier pitches and saved the better ones for Poceta.

“Like a proud parent, I wanted the unfinished route to make a good impression,” he wrote.

Partway up the fourth pitch, a big corner, Poceta called down to ask whether to go left or right at the roof. There had been no roof on that pitch. When Slawinski followed, he found that “a house-sized chunk of the corner had fallen off” sometime over the winter.

The next summer, the pair found the pillar beside that corner leaning away from the wall and rerouted around it.

“We realized that the crack beside this pillar was slowly getting wider, that the whole thing was starting to lean outwards,” Slawinski said.

Slawinski and Poceta completed Daddy Longlegs on Sept. 3, 2022, two decades after the first attempt.

The route linked three generations of climbers: DeMaio, a leading Bow Valley climber of the late 1980s and early 1990s; Slawinski, an internationally recognized alpinist; and Poceta, whom Slawinski calls “the best all-round rock climber by far in the Bow Valley right now.”

Now much of it is gone. What’s left includes what climbers call hangfire, which Slawinski describes as “loose rock barely attached, still threatening to fall.”

“That sector of the face anyway would not be a very safe place right now... It might not be a once and done thing,” Slawinski said.

Recent Rockfalls In The Bow Valley

The Windtower rockfall follows several other high-profile rockfalls in the region.

On June 1, a rockslide on Canmore Hill closed Spray Lakes Road (Highway 742). Repairs, including removing loose rock and installing rock bolts, cost about $1.1 million, and the road reopened Aug. 21, almost 12 weeks later.

Then, On July 7, a rockfall at Rundle Rock near Banff destroyed the start of Ridge of Death, a climb first done more than 50 years ago, according to Gripped magazine.

Parks Canada had kept the area, including several popular climbing walls, closed “to all traffic and travel” following the incident.

On June 19, 2025, a rockslide on the Bow Glacier Falls trail in Banff National Park killed two hikers. The trail reopened in July this year.

What Happens To The Routes Now?

Route development in Alberta’s provincial parks is largely unregulated, according to Beaudry. Much of the work is done by volunteers, with help from groups such as the Association of Bow Valley Area Rockclimbers (TABVAR).

TABVAR raises money to help cover the cost of installing and maintaining bolts and other fixed hardware on climbs in the Bow Valley and nearby areas.

Changes to routes are usually shared by word of mouth, social media and crowdsourced sites such as Mountain Project.

Slawinski said the Canadian Alpine Journal, published once a year, serves as “a more permanent record of what’s been done, what’s been undone.”

Both Slawinski and Beaudry said they wouldn’t be surprised if someone eventually goes to look at the new face.

“I can think of one or two people who might see this as a blank canvas,” Slawinski said.

Beaudry said the face was never popular because of how hard and committing the climbing is. For those “bold enough and motivated,” he said, the new roof may be an opportunity, but not one most climbers will want.

“There's no roofs like this in the Canadian Rockies because they fall off... So this roof will exist for some moment in time,” Beaudry said. “It takes a certain person to go rap into Windtower and look for a route.”

For Slawinski, however, the value of Daddy Longlegs wasn't dependent on whether the route survived or someone else climbed it.

“I mean, it would have been cool [if] someone had repeated it, but… I just had some really good days on it and had some really good experiences in it. And so in a way, I got what I wanted out of the route,” he said.