The History of Ice Road Trucking

Canada’s Northwest Territories are a wild and forbidding landscape with short Arctic summers and long winters where temperatures routinely reach -40°F. Indigenous Dene people have called the "bush” home for millennia, but it was the discovery of gold near Yellowknife in the 1930s that attracted a rush of outsiders eager to exploit the remote territory’s resources.

What they quickly discovered was how difficult and dangerous it was to transport heavy equipment, supplies and precious metals across the rocky, lake-strewn country. In the summer, barges could navigate rivers and lakes to reach Yellowknife, but overland travel was nearly impossible. The terrain became a patchwork of lakes and ponds in summer, while winters brought impassable snow.

Where some saw insurmountable obstacles, though, others saw a challenge. The solution, those transport pioneers discovered, was ice. For a short window every year—just 8 to 10 weeks—the ice was thick enough to withstand heavy loads topping 50 tons, even over deep lakes. And that’s how the fabled ice roads were born.

The First Ice Roads

The very first ice roads in Canada were built in the 1920s by an Icelander named Svein Sigfusson, a commercial fisherman who harvested walleye under the thick winter ice of Lake Winnipeg in Manitoba. The biggest challenge was getting the fish to market, says Bill Braden, a journalist and photographer from Yellowknife who wrote On Good Ice: The Evolution of Canada’s Arctic Ice Road.

To reach the nearest rail line, Sigfusson first relied on early Caterpillar tractors and horse-drawn sleighs, but travel was painfully slow. When diesel trucks became available in the 1920s, he wondered how the tires would perform on ice.

From his fishing experience, he knew that drilling a hole in the ice allowed water to seep onto the surface, creating an even thicker layer. He began to experiment—clearing snow and flooding the lake ice to build up a surface capable of holding a fully loaded truck.

Those early ice roads showed what was possible—to transport cargo with the speed and efficiency of a truck even in the depths of the Canadian winter.

The real genius of Sigfusson’s system was how he dealt with “portages,” the sections of land between lakes. To smooth over those rough and rutted areas, he packed them with snow and sprayed them with water, creating a continuous icy surface over which the lumbering trucks could travel.

320 Miles to Port Radium

After the Yellowknife gold rush of the 1930s, more precious metals—including radium, cobalt and silver—were discovered at Port Radium on the shores of Great Bear Lake. During the 1940s and 1950s, the only viable transport route to Port Radium was in summer, when tugboats and barges could wind upriver to deliver much-needed equipment, fuel and supplies, and return with shipments of ore. But the delivery window was short.

What about building an ice road from Yellowknife to Port Radium to transport some of those heavy loads during the winter? Port Radium was more than 320 miles north of Yellowknife through some of the most difficult terrain imaginable. If Sigfusson’s roads were proof of concept, the man who firmly established ice roads as a viable long-distance transport route was John Denison.

Denison was a World War II veteran and a former police officer in Yellowknife who stumbled into the commercial trucking business and made his name as a risk-taker. In the 1960s, he built the first long-distance ice roads across the windswept Barren Lands of the Arctic.

“He proved that it was viable to get trucks over this remarkably challenging, brutal country in the winter,” says Braden, whose father worked as a mechanic with Denison. “People thought he was nuts to even attempt it, but he was a trucking guy at heart and said, ‘Hey, I think we can do this.’”

Building Denison’s Ice Road

Through trial and error—and a few sunken trucks—Denison perfected the ice road-building process in the 1960s and 1970s. Many of his techniques are still used today, with updated equipment.

Ice roads work on the principle that snow is an insulator. Even in subzero temperatures, lake ice won’t get thick enough if it’s covered in a deep pile of snow. Denison learned that the trick to building an ice road is to clear off as much snow as possible—or compress the snow into a thin, dense layer—and encourage the ice to thicken from below.

Denison started building his ice road right after Christmas. First, he scouted the route overhead with an airplane, then he used a tracked vehicle called a “Bug” to check on the condition of portages. Ninety percent of Denison’s ice roads were over water, but the 10 percent on land were always the hardest to build.

Once the ice on the lakes was at least 18 inches thick, Denison set out with his road-building crew of Caterpillar tractors, plow trucks, water trucks and graders to make a first pass. By early February, his ice road was ready for truck traffic.

“Once you have even a primitive, very narrow road plowed over the ice, the ice is going to build relatively quickly,” says Braden. "Within a week or two, you'll be able to put a reasonably heavy load on it.”

How Dangerous was Ice Road Trucking?

No question, ice road trucking was treacherous in those early days. A truck driver’s greatest fear, Braden says, was a “blowout.” Lake ice is buoyant and sags under the weight of a fully loaded truck.

“If you’re standing on an ice road and a big, heavy load drives past you, you can feel the ice deflect at least a foot, maybe two feet,” says Braden.

That downward pressure forms a wave under the ice in front of the moving truck. Under the right conditions, that wave can bounce off the shoreline and echo back toward the truck with enough force to rupture the ice.

“If that wave punches its way up through the ice and you’re not in control, then you’re in deep water,” says Braden.

Ice road pioneer Svein Sigfusson wrote about his own fears of breaking through while behind the wheel of a truck.

“My own last-ditch survival secret was to be afraid at all times,” wrote Sigfusson. “I made myself a very cautious coward on ice, developing a hair-trigger coward’s reflex with which I jumped off four sinking tractors in 25 years and never got wet above the hips.”

Decades later, journalist Edith Iglauer traveled with John Denison as he built and drove the treacherous ice road to Port Radium.

“On the ice road, especially during a lake crossing, a driver is apt to keep one hand on the steering wheel and the other on the handle of the door beside him, which he may have left ajar,” wrote Iglauer in her 1974 book, Denison’s Ice Road. “When a driver and his truck run out of ice, it’s time to jump and every second counts.”

Today’s ice road technology has all but eliminated the hazards faced by the pioneers. Builders employ decades of road and maintenance know-how, strict safety rules and continuous monitoring. Science, too, has played a big role in testing the limits of heavy loads on as little as 4 feet of ice. Braden figures that per mile driven, they’re among the safest roads in North America.

Ice Roads and the Diamond Boom

The next big milestone in ice trucking history was the discovery of diamonds in 1990 in the northernmost reaches of the Northwest Territories.

“We're talking about a piece of the country that is about as far away from anywhere else as you can get,” says Braden. “Look for a part of the map that's absolutely vacant and that’s where those diamond mines are.”

Four large diamond mines began operating in this remote, blizzard-ravaged region in the 1990s and ice roads were absolutely critical to their success. By 1997, Braden says, there were 3,000 truckloads traveling the 280-mile ice road to the mines every season. They hauled everything from massive mining equipment to fuel to prefabricated housing.

Today, after a six-week construction season ends in late January, and for the next 8 to 10 weeks, a steady caravan of vehicles travels from Yellowknife to the diamond mines 24 hours a day. The road shuts down in early April when rising temperatures begin to melt the ice on the portages, which thaw faster than lake ice.

The sharp increase in traffic—typically around 7,000 loads a year—required stringent new safety measures such as maximum speed limits of 20 mph when fully loaded, continuous radar surveys to monitor ice thickness along the route, and security patrols to guard against speeding and help stranded drivers.

The ice roads of the Northwest Territories were, and remain, a logistical marvel. They enable the transport of a year’s worth of critical fuel, steel, cement and explosives during a vanishingly short season. What’s even more remarkable to Braden is that ice roads are temporary.

“They build these things and then watch them melt,” says Braden. “And then they do it all over again at a cost well north of $20 million a year.”