MOUNT REVELSTOKE, B.C. – During the first week of January, Mother Nature dumped a heavy load of snow in the Rocky Mountains, bringing traffic to a standstill.

The road closure along the 18-km stretch of Trans-Canada highway, which snakes the scenic mountain range through Rogers Pass, lasted a little more than a day, but left hundreds of motorists stranded. Not a parking space or hotel room went unused in a number of towns dotting the route, stretching from Golden, B.C. in the west to Lake Louise, Alta. in the east.

The largest snowfall of this winter season was joined by natural avalanches, which thundered across the highway in the Kicking Horse Canyon near Golden.

“Every hour the highway is closed, it incurs costs in lost shipping on both the highway and rail lines in the area,” said Lt. Rob Vandermolen, Troop Commander of the 1st Royal Canadian Horse Artillery (1 RCHA) from Canadian Forces Base Shilo, Man.

Vandermolen and the 13 soldiers under his command, used artillery fire to trigger several manmade avalanches in Rogers Pass during the road closure as well, to prevent further volatility of a naturally occurring avalanche.

“Our goal is to induce an avalanche before it can become larger and therefore a danger to traffic,” explained Vandermolen. “Using the artillery to induce the avalanche allows us to determine when an avalanche will take place, preventing hours, maybe days of road closures that could result if we were to wait for nature.”

For more than 45 years the 1 RCHA has used artillery fire to assist Parks Canada with avalanche control in Rogers Pass.

The operation, dubbed Operation Palaci 2006, is a Parks Canada-run program that is augmented by three rotations of 13 members of 1 RCHA, with a Troop Sergeant Major (TSM) and a Troop Commander. The members form two gun detachments to fire artillery from 105-mm howitzers, which are towed in advance to one of 18 roadside circular gun platforms throughout the park.

“The overall command structure is formed by the Parks Canada senior snow expert, giving guidance to myself and the TSM as to whether preparations will be made for firing that day, at any time,” noted Vandermolen. “Firing can and has happened at early hours until sun-up in order to close the highway for firing at low traffic times.”

Parks Canada operates the world’s largest mobile avalanche control program. During winter months, snow avalanche technicians maintain a constant watch over weather and snowpack conditions. The artillery takes its cues on when and where to fire from these snow experts.

“Our daily routine is dictated by my meeting with Parks Canada each morning, dependant upon whether we are firing that day or not,” added Vandermolen.

When dealing with Mother Nature, no day can be described as typical, but essentially a typical firing day for the avalanche control team will begin with Parks Canada sweeping the highway east and west to ensure no civilian vehicles are present within the danger area or slide areas.

“When engaging an avalanche path, under my direction – and I take cues from Parks Canada – the supervisor of that gun will point the gun onto a known angle in relation to a fixed reference object by the use of a sighting periscope,” explained Vandermolen. “Once laid, the barrel will be elevated to a known elevation and the gun will be loaded.”

After a few more calculations, radio communication and confirmation, the round is fired into known trigger zones high up the avalanche paths. The shock waves from exploding shells fired by the artillery will trigger avalanches when snow conditions are right.

“It can take minutes to hours in order to achieve the required results with 18 positions and more than 150 known targets over 40 kilometres in distance,” noted Vandermolen.

The length of a firing day is based on a number of weather variables that need to be adjusted for and no shoot is ever the same.

“Each target has a ‘sweet spot’,” explained Vandermolen. “If we’re lucky, weather conditions, like sunlight, will aide us in softening the target up and the sweet spot will yield a good slide. If not, we may have to engage other targets in order to get the slide we’re after.”

Working alongside the soldiers is a number of road crews, including snowplow drivers and traffic control workers, formed by local residents from Golden and Revelstoke.

“It’s a team effort,” added Vandermolen. “Parks Canada personnel are coordinators, road crews remove snow and ice, and us Army guys are the ‘snow-punchers.’ Each of us plays an essential part and lends expertise in our related fields.”

When gunning against Mother Nature, there’s no guarantee even a joint effort team between Parks Canada and the Armed Forces can always come out on top, but without their efforts more truckers may get parked along the Trans-Canada Highway during a winter Rocky Mountain drive.

“In my opinion, any amount of time dedicated to keeping the highways safe from avalanches is time well spent,” noted Vandermolen.