1959 John Denison's Ice Roads

One of the greatest impediments to northern mining development from the 1930s through to the late 1950s was transportation. Using airplanes to bring supplies and heavy equipment into mine sites was too expensive so cat-trains – a Caterpillar tractor pulling large freight laden sleighs – were used but they were slow, traveling at best only a few kilometres per hour.

John Denison, a veteran of World War Two and a former RCMP officer, owned and operated one of these cat-trains. He had contracts to haul freight to some of the isolated mines in the Northwest Territories and became frustrated by the weeks of travel it took to get to just to one of these sites.

In 1959 the Rayrock Uranium Mine northwest of Rae (map) closed down and Denison had the contract to move some of the buildings from there to the Discovery Mine a hundred kilometres north of Yellowknife. It was then that he began to experiment with different ways of building a road across frozen lakes and portages that could be used by regular transport trucks.

Snow on lake surfaces keeps the ice from getting thick enough to support large trucks while snow on the land can keep muskegs from freezing solid. Denison found that if he ploughed the snow from a route across a lake the ice would grow in thickness from the bottom as the cold penetrated. He also found that on the portages it was best to just pack the snow down; this would allow the ground to freeze solid while also keeping the road relatively smooth.

Denison used a Bombardier or ‘Bug’ for scouting out ice road routes; Caterpillar tractors for clearing portages; trucks with snow ploughs on the front for clearing snow from lakes; and a vehicle which Denison called a ‘Beaver’ with balloon tires for packing snow on portages. He also designed and built several different types of chain drags pulled behind old military vehicles that would knock the air out of the snow while also smoothing the surface.

Over the years the ice road construction methods developed by John Denison have been refined and today the more than 2500 km of ice roads are an essential part of the transportation system in the Northwest Territories.

Timeline Link: 1959 First on the Yellwknife Highway

Timeline Link 1948 Mackenize Highway