Mount Baker Tunnel

The Mount Baker Tunnel is a road tunnel in Seattle built in 1940 beneath Mount Baker Ridge as part of the original Lake Washington crossing infrastructure. Twin tubes with two lanes each were later expanded with a larger parallel tunnel opened in 1989 to handle growing traffic demands.

The tunnel opened in 1940 as part of the first Lake Washington crossing project, connecting Seattle to the Eastside and marking a turning point in the city's expansion. More than eleven thousand vehicles used the route on opening day, demonstrating the immediate impact of this transportation link.

The tunnel features decorative concrete portals with symbols of the Pacific Ocean and Asian influences that reflect Seattle's international trading role. These artworks, created through New Deal art projects, blend engineering with cultural expression and mark the entrance as a welcoming gateway to the region.

Vehicles pass through via Interstate 90, with a dedicated walking and biking path running alongside known as the I-90 Trail, the longest of its kind attached to a highway. The tunnels are well lit and regularly maintained, ensuring safe passage for all users.

On opening day, more than eleven thousand vehicles passed through the tunnel in just over ten hours, immediately demonstrating its importance as a city link. Drivers developed a long-standing habit of holding their breath when passing through, especially at the nearby bridges.