Building a stronger connection in Canada’s North: Replacing Yukon’s Mayo River Bridge

For nearly seven decades, the Mayo River Bridge has connected residents in northwestern Canada to essential services. Jacobs is working with the Government of Yukon to design its replacement, safeguarding a vital connection for the region.

The existing bridge, a small, pony truss bridge originally built in 1957, spans the Mayo River at kilometer 49.8 of Silver Trail Road. It has endured decades of harsh northern conditions, but recent inspections revealed serious structural and geotechnical concerns: the bridge’s foundation and key parts are damaged or unstable, and the surrounding soil and river conditions make things worse — so the bridge needs major repairs or replacement to stay safe and maintain continuity of services to the community.

The urgency of the project is amplified by the Yukon Energy Mayo Generating Station upgrades currently underway. As the community’s sole access route, the bridge will serve as a vital corridor for transporting equipment and materials for this major infrastructure initiative, making timely delivery essential.

Jacobs’ team will deliver comprehensive design and engineering services for the project, including the structural design of the new single-span bridge, geotechnical design, civil and highway design, hydrotechnical assessment and design, field survey, constructability reviews, and tender, construction and post-construction support. This full-scope approach allows for seamless coordination across disciplines and helps anticipate challenges early — critical to delivering safely and efficiently in Yukon’s demanding northern environment.

Replacing the bridge is no small feat. The site sits in a remote boreal valley, surrounded by floodplains and rolling uplands with steep slopes, where seasonal access constraints and limited local resources add complexity. Its very remote location is roughly a five-hour drive from Whitehorse, the nearest major city, making material supply, such as concrete, a key consideration in the design.

Construction timelines are further constrained by the Yukon’s short warm-weather construction season, which limits how long crews can work safely and efficiently each year. Together, these factors make speed and efficiency essential to the project’s success.

To address these challenges, our team is designing the bridge for rapid construction. The project will use Accelerated Bridge Construction methods, which rely on major components being built off-site and delivered ready to install. The bridge will be assembled primarily from prefabricated steel components and precast concrete elements, reducing the amount of concrete that must be poured onsite. On-site concrete work will be limited to connecting the prefabricated elements.

This approach reduces construction time, minimizes weather-related risks and lowers overall costs while maintaining quality and durability.

Jacobs will also draw on other best practices from similar northern projects, including the near-complete Jean Marie River Bridge Replacement project. The Jean Marie River Bridge, originally built in 1969 on Highway 1 near Fort Simpson in the Northwest Territories, had reached the end of its lifecycle, requiring full replacement to maintain safety and reliability for road users. Jacobs provided engineering services for that critical infrastructure upgrade, replacing the aging single-lane structure with a modern bridge designed to withstand extreme northern conditions and future climate impacts. Jacobs will apply lessons learned from the Jean Marie River Bridge to mitigate risk and deliver resilient solutions under Yukon’s similar challenging conditions.

"The Mayo River Bridge replacement is a critical step toward building a future-ready transportation network in Yukon," says Jacobs Transportation Market Growth Director for Canada, Alex Chan. "By combining innovation with environmental stewardship, we’re delivering a project that meets today’s needs and anticipates tomorrow’s opportunities, while navigating some of the most demanding terrain and climatic conditions in Canada’s North.”

As work begins, the project promises not only a safer, more reliable crossing but also a foundation for economic development and improved connectivity in Yukon’s rugged heartland.