Many of the workers on this segment were hard-rock miners, who blasted out the sides of steep slopes 500 ft to 1,500 ft above the roaring Kicking Horse River and the turbulent Fraser River.

Where the route passed through Glacier and Revelstoke National Parks and Rogers Pass, avalanches and snow slides were real dangers. At one point during the project, explosives placed to trigger avalanches as a test were eaten by grizzly bears before they could be detonated.

Over 4,000 ft of snow sheds made of timber or reinforced concrete protected the most vulnerable stretches of highway. Treacherous saturated soil conditions around bridge piers near Terrace Bay, Ontario, called for an unusual solution. Electro-osmosis was used to stabilize the wet, fine-grained soils while foundations were constructed.

The technique involved setting up direct current between electrodes placed in soil to induce the flow of water, along with ions, from anode to cathode. This controlled direction of seepage forces reduced water content in the soil, changing its chemical composition and successfully stabilized the soil. Construction lasted nine years, with the highway opening in 1960.

This April 1959 cover image depicts a right-of-way for the Trans-Canada Highway being carved through a stretch of the Canadian Rockies in British Columbia. This 143-mile section was the most difficult to construct of the entire 4,470-mile route, stretching from St. Johns, Newfoundland, on the Atlantic Ocean, to Vancouver, B.C., on the Pacific coast.

Many of the workers on this segment were hard-rock miners, who blasted out the sides of steep slopes 500 ft to 1,500 ft above the roaring Kicking Horse River and the turbulent Fraser River. Where the route passed through Glacier and Revelstoke National Parks and Rogers Pass, avalanches and snow slides were real dangers.

At one point during the project, explosives placed to trigger avalanches as a test were eaten by grizzly bears before they could be detonated. Over 4,000 ft of snow sheds made of timber or reinforced concrete protected the most vulnerable stretches of highway. Treacherous saturated soil conditions around bridge piers near Terrace Bay, Ontario, called for an unusual solution.

Electro-osmosis was used to stabilize the wet, fine-grained soils while foundations were constructed. The technique involved setting up direct current between electrodes placed in soil to induce the flow of water, along with ions, from anode to cathode.

This controlled direction of seepage forces reduced water content in the soil, changing its chemical composition and successfully stabilized the soil. Construction lasted nine years, with the highway opening in 1962.