Highway 742 above Canmore to reopen by end of August after June rockslide
Highway 742 above Canmore is set to reopen by the end of August after emergency rock-scaling and stabilization work following a June 1 rockslide, provincial officials say.
Strong opening: closure since June 1 disrupted access
A rockslide on June 1 sent boulders and debris onto Highway 742 above Canmore, forcing the closure of the mountain road that provides primary access to the Spray Lakes area. The closure blocked access to Grassi Lakes and other trailheads, disrupting summer recreation and local traffic for nearly two and a half months. Alberta Transportation and Economic Corridors now says major mitigation work is advancing and a reopening target has been set for the end of August.
Planned reopening timeline
Provincial officials caution the reopening date remains conditional on construction progress and safety checks. They say crews must finish the full scope of emergency rock scaling and slope stabilization before traffic can return to normal operations. The timeline may change if crews encounter additional unstable rock or adverse weather, the ministry warned. For now, the end-of-August window is the working schedule provided by the province.
Emergency rock-scaling operations under way
Work on the slope above Highway 742 focuses on removing loose and unstable rock and installing rock bolts to secure larger sections of the face. Crews are using controlled rock scaling to dislodge hazardous blocks, then securing anchor points to reduce the risk of future falls. The province described the activity as necessary to address an ongoing overhead hazard that also poses an avalanche risk. While crews operate on the slope, overhead work continues to generate falling debris, preventing intermittent traffic from being permitted.
Access alternatives and trail impacts
Although the Canmore-side route remains closed, visitors can still reach many popular destinations from Highway 40 to the south, including Ha Ling Peak and parts of the Spray Lakes network. Access to Grassi Lakes and some local trailheads, however, remains restricted from the Canmore approach until the road reopens. Outdoor groups and trail stewards say some users have shifted entry points or postponed trips while the mitigation work proceeds. The closure has been especially inconvenient during peak summer months when hiking and biking traffic is highest.
Safety restrictions bar intermittent traffic
Alberta Transportation emphasized that the presence of active rock removal operations makes any intermittent traffic unsafe while workers continue overhead scaling. Officials noted that even temporary single-lane openings would expose motorists and crews to falling blocks during work windows. The ministry said the priority is to complete mitigation and secure the slope to a standard that allows normal road operations to resume. Until then, signage and closures will remain in place and enforcement may continue to restrict vehicle movement on the affected stretch.
Cost, recent storms and regional impacts
The emergency work on Highway 742 is estimated at roughly $1.1 million, the ministry reported. The June rockslide followed heavy rains that also triggered separate washouts and, later in June, left about 1,500 campers temporarily stranded in Kananaskis Country during a separate storm event. Elsewhere in the region, Powderface Trail remains closed after a washout near the Dawson campground area, affecting access to foothills trails and recreation sites. Friends of Kananaskis Country and other trail volunteers reported damage to routes in the Ware Creek and Cox Hill areas, though they said the destruction was not on the scale of the catastrophic floods of June 2013.
A spokesperson for the ministry reiterated that public safety guides the work and that reopening will only occur when the slope is secured and inspections are complete.
