Glacier National Park (Canada): landscape and origins
Steep Selkirk slopes, moist Pacific air and up to ten metres of new snow each winter make a landscape that keeps falling down on itself: over 40 kilometres (25 mi), the Trans-Canada Highway passes beneath 135 avalanche paths.
The park protects the heart of the Selkirk and Purcell Mountains, the highest ranges in the Columbia Mountains system. Moist Pacific air drops its rain and snow here before it reaches the Rocky Mountains. Down below, this produces the world’s only inland cedar rainforest; up above, up to ten metres of new snow. Between the valley floor and the ridges lie more than 2,000 m (6,562 ft) of elevation.
This very combination makes the transport corridor dangerous. Since 1961 the park authority and the Canadian Armed Forces have kept the highway open with artillery fire, the largest mobile avalanche control programme in the world. Avalanche technicians collect weather and snow data every day at study plots at Rogers Pass (1,315 m (4,314 ft)) and on Mount Fidelity (1,905 m (6,250 ft)), dig profile pits up to five metres deep and test the snow layers with the rutschblock test.
If the snowpack is not stable enough, the road is closed and the slopes are shelled. The 105 mm howitzer is fired from 17 fixed positions at 270 pre-set targets; thanks to the pre-calibration, it can hit them even at night and in heavy snowfall. The guns are operated by the Royal Canadian Horse Artillery under the direction of Parks Canada’s senior avalanche officer, as part of Operation PALACI, for which two groups of 15 to 20 gunners each deploy from November to April.
A single March storm shows how much depends on it: 271 rounds fired triggered 37 large avalanches. Without this control, Parks Canada estimates, the highway between Revelstoke and Golden would have been blocked for more than twelve days. Every hour of closure costs the Canadian economy over three million dollars.
At the end of April 2026 the military announced that it would not renew the 65-year-old agreement: it expires on 17 August 2027, citing pressure on resources and the planned retirement of the old artillery systems. Winter 2026/27 is therefore the last with artillery support. Parks Canada and the Department of National Defence are still negotiating what happens after that.
Parks Canada: avalanche control in Glacier National Park ↗
The park in numbers
- Established
- 1886, British Columbia’s first national park
- Order
- Canada’s second after Banff, at the same time as Yoho
- Mountains
- Selkirk and Purcell, Columbia Mountains
- Rogers Pass
- 1,315 m (4,314 ft)
- New snow
- up to 10 m (33 ft) per winter, 14 m (46 ft) on average at the pass
- Avalanche paths above the corridor
- 135
- Pre-set artillery targets
- 270 from 17 gun positions
- Avalanche programme
- since 1961, ends 17 Aug 2027
- Retreat of the Illecillewaet Glacier
- about 1.5 km (0.9 mi) in 100 years
