The wildlife crossing system in Banff National Park is a world-leading ecological infrastructure project designed to mitigate the fragmenting effects of the Trans-Canada Highway (TCH). What began as a contentious twinning project in the early 1980s has evolved into the “Banff Model,” now replicated in crossing designs globally.

The barrier effect

The Trans-Canada Highway, which bisects the Bow River valley, is one of the busiest transport corridors in Canada. For large mammals, the high-speed traffic and concrete dividers create a near-impenetrable barrier to genetic flow, seasonal migration, and forage access. Without intervention, populations of Grizzly Bears, Gray Wolves, and Wolverine would face localized extirpation due to isolation and vehicle-strike mortality.

Infrastructure and design

The system consists of 38 wildlife underpasses and 6 overpasses between the park’s east gate and the Kicking Horse Pass. These structures are linked by 2.4-metre-high specialized fencing that funnels animals toward the crossings. The overpasses are 50 metres wide and landscaped with native soil, trees, and shrubs to mimic the surrounding forest, providing a visual and acoustic buffer from the highway below.

Species-specific preferences

Research conducted by Parks Canada and collaborating biologists reveals distinct preferences among species:

Overpasses: Favoured by “shy” species that prefer open vistas and light, including Grizzly Bears, Moose, and Elk.
Underpasses: Preferred by Cougars and Black Bears, who often seek the security of covered, darker environments.
Genetic flow: Wolverines, one of the most elusive species in the Rockies, have been documented using both overpasses and underpasses to cross the highway, a critical finding for the persistence of this low-density carnivore.

The “Learning Curve”

Wildlife usage is not immediate. Many species exhibit a multi-year “learning curve” before regularly utilizing the structures. Gray Wolves and Grizzly Bears may take up to five years to adapt to new crossings, while Elk and Deer often use them within the first season.

Effectiveness and statistics

The crossing system has transformed the TCH from a death trap into a permeable corridor:

Collisions: Overall wildlife-vehicle collisions have been reduced by over 80%.
Ungulates: For Elk and Mule Deer, the reduction in mortality is as high as 96%.
Usage counts: Remote cameras have documented over 200,000 individual crossings by 11 species of large mammals.

Local corridors: Fairview and Whitehorn

In the immediate vicinity of Lake Louise, two major corridors are critical for carnivore movement:

Fairview Corridor: Bypassing the Lake Louise Village, this corridor allows bears and wolves to move between the Bow River and the high-alpine basins of Mount Fairview.
Whitehorn Corridor: This corridor traverses the lower slopes of the Lake Louise Ski Resort. The resort manages summer operations, including the Grizzly Gondola, to minimize impact on these transit routes.

Connectivity beyond the park

The Banff system is part of the broader Yellowstone to Yukon (Y2Y) conservation initiative. By maintaining connectivity across the TCH, Banff serves as a critical link in a continental-scale corridor that allows for the long-term survival of wide-ranging species in a changing climate.

Wildlife Crossings