Snohomish County can begin work to bring to life the last 12 miles of the Centennial Trail.

The railbanking proceedings for the section of rail line south of the City of Snohomish to the King County line concluded on July 11, 2024. The federal Surface Transportation Board (STB) authorized interim trail use and railbanking of the old line. Railbanking is a voluntary agreement between a railroad company and a trail agency to use an out-of-service rail corridor as a trail until rail service in the corridor is reinstated.

Snohomish County can now move forward with the design, permitting and eventual construction of the Centennial Trail South. The design process will resume in 2025 with initial design and planning of the corridor and will include a public engagement process.

“This important trail connection has been a long time coming. I am excited that we can move forward with bringing this asset to the public,” Snohomish County Executive Dave Somers said in a press release. “Trail projects like this bring opportunity for Snohomish County residents and visitors. They can enjoy the beauty of our county while walking or riding the trail for recreation, and for active transportation in our growing communities.”

The Centennial Trail South extension will complete a critical missing link in Snohomish County’s regional trail system, connecting the Centennial Trail from the Skagit County line to the King County line, providing 42 miles of separated, shared-use trail. The trail will continue into King County as the Eastrail, continuing an additional 30 miles through the communities on the east side of Lake Washington and connecting to over 175 miles of a larger regional trail network. The future Centennial Trail South will accommodate both pedestrian and bicycle usage.

“I look forward to the day the community can walk and ride along this 12-mile stretch of trail. But because of the complexities of this project, it is going to take more than a decade to complete it. We want people to know that this section of the Centennial Trail is not open to the public at this time,” said Tom Teigen, county conservation and natural resources director.

The alignment has complex attributes, including 60 culverts, 13 at-grade crossings and 7 elevated crossings. As a result of these complexities and due to the projected funding needs, trail construction is expected to occur in phases over the next decade, or more.

Snohomish County acquired the railroad right-of-way south of the City of Snohomish to the King County line from the Port of Seattle in 2016.