More than 24 hours after an attempt to trigger a controlled avalanche brought down more snow than intended and buried part of the Icefields Parkway near Lake Louise, there's still no sign of when the section of road will be re-opened.

"We have road crews in there with heavy road machinery," Parks Canada spokesperson Tania Peters told CBC News Friday.

"We're working to clear out that debris. There is a large volume of it. It's going to take them some time," Peters explained.

The Icefields Parkway, which is a section of Highway 93 North, is blocked between Lake Louise and the Saskatchewan River Crossing. The snow debris is 15 metres deep and covers 100 metres of road, Peters said.

Crews triggered the initial avalanche as part of their seasonal risk reduction efforts, but it brought down more snow than intended.

An aerial view of the avalanche shortly after the deluge gave way from Mount Hector. (Banff National Park) "Routine avalanche control work on the Icefields Parkway yesterday [Thursday] evening produced a larger result than expected from Mt. Hector," according to a statement on the Banff National Park Facebook page.

Park officials immediately closed Highway 93 north between the Trans-Canada Highway and Highway 11 after the avalanche was triggered.

At the time, officials expected the route to be closed for at least 24 hours.

The avalanche buried a stretch of road on the Icefield Parkway between Lake Louise and the North Saskatchewan Crossing. Avalanche technicians and road crews remained on-scene Thursday night.

Rock slide near Jasper

Hours after the avalanche, a rock slide closed a stretch of the Yellowhead Highway from the Jasper townsite to the B.C. border around 9 a.m. Friday morning, Jasper public relations spokesperson Joseph Zebrowski confirmed.

That closure remains in effect until a geotechnical expert can do a full assessment of the area.

As of Friday evening, park officials do not have an estimate on when the highway can be re-opened. "We really need that assessment first," Zebrowski said.

Due to the spring thaw, the avalanche risk in the Rockies is considered extremely high, according to Thursday's forecast from Avalanche Canada.

"A widespread avalanche cycle continues where large avalanches are running well below tree line into snow-free bushy runouts," said the latest forecast for Banff, Kootenay and Yoho national parks.

Crews remain at the scene of the "controlled" avalanche on Icefields Parkway. (Banff National Park) "There is no overnight recovery. It's time to avoid all avalanche terrain and runouts. The hazard will remain high to extreme."The hazard rating in the Jasper region was rising to extreme for Friday, and backcountry users were advised to be extra cautious.

"[It] still looks like winter in the higher elevations but change is coming rapidly. Significant rain and freezing level rising to mountain top," said the latest avalanche bulletin for the Jasper area.

"Good day to stick to riding on the ski hill."