Snohomish County wants to hear from trail users before it designs a 12-mile southward extension of the Centennial Trail, and an online survey is open through the end of August.

The Centennial Trail South Extension would run from the City of Snohomish to Woodinville along the former Eastside Rail corridor, connecting the county's existing 30-mile trail to King County's Eastrail network.

That link would stitch together a continuous route from the Skagit County line to communities on the east side of Lake Washington, tapping into more than 175 miles of regional trails including the Burke-Gilman and Sammamish River trails.

Snohomish County Parks & Recreation announced the planning launch on Wednesday, July 22. The county has secured $2 million from county and state funds for engineering studies and preliminary design of the full corridor. The county targets 2027 for completing a conceptual design and feasibility study that will guide phased construction.

Full buildout could reach $100 million, according to a 2024 Snohomish County Tribune estimate cited by Seattle Bike Blog. The county has not confirmed that figure in its current materials.

Additional grant funding will be needed, and construction will happen in phases "over the coming decade and beyond," according to the county announcement.

"Completing the Centennial Trail has been a vision for decades, and we're excited to take this important next step," County Executive Dave Somers said in the announcement. "Community input will play a critical role in shaping that vision."

Parks & Recreation Director Sharon Walker called the Centennial Trail "one of Snohomish County's most treasured recreational assets" and said the planning process gives residents a chance to weigh in on trail access, amenities, and the corridor's natural character.

The corridor itself is no simple path. It includes 60 culverts, 13 at-grade crossings, and seven elevated crossings, plus bridges, trestles, wetlands, and steep terrain.

A fire on Tuesday, May 12 burned roughly 300 feet of trestle south of Snohomish; the county is still assessing damage with Snohomish County Fire District 4 and BNSF Railway.

The existing Centennial Trail runs 30 miles from Snohomish north through Lake Stevens and Arlington to the Skagit County line and draws more than 500,000 users a year.

It first opened in 1989 and reached its current length in 2013. The county acquired the southern right-of-way from the Port of Seattle for $3.5 million in 2016, and the Surface Transportation Board authorized railbanking of the corridor on July 11, 2024.

For Everett-area residents who bike, walk, or run the northern Centennial Trail, the extension would open a continuous southbound route without needing to load bikes onto a car.

The survey is available in English and Spanish. The county says community outreach events are planned for July and August but has not yet posted dates or locations.

Check snohomishcountywa.gov/561/Centennial-Trail-South for updates. The project contact is Senior Park Planner Emily Griffith at 425-388-6620.

Construction timelines will depend on engineering, environmental review, permitting, and funding. The county is hiring a consultant team to support the design process.