Note: this information is a search for "Centennial Trail South" on the Snohomish County website. 

The 2016 acquisition of Centennial Trail South extends the current Centennial Trail from the City of Snohomish south to Woodinville in King County. This 12 mile rail-with-trail corridor will complete the regional trail through Snohomish County, from the Skagit County line to the King County line and will eventually connect to the King County trail system further south.

The new trail section will be similar to the existing Centennial Trail, and will accommodate both pedestrian and bicycle usage. The proposed alignment traverses areas with steep cross slopes, bridges, trestles, sloughs and other natural features which complicate construction. As a result, trail construction is anticipated to take place in phases.

If you want to know more:

https://www.snohomishcountywa.gov/561/Centennial-Trail-South-2024