Green River Trail North Extension
Location:
This project would extend the existing Green River Trail north from Cecil Moses Park in Tukwila, along W Marginal Place S to the Seattle City Limits near South Park, thus completing an important regional trail link.
Construction update:
This project is in the preliminary design phase. To review the project history and leave comments, visit the project Public Input site.
Recent Activity:
Trail Route Recommendation - King County is recommending a unique approach to routing an extension of the Green River Trail from Cecil Moses Park to Seattle's south border at Director Street. The County has conducted an Alternative Alignment Analysis for the Green River Trail North Extension that assessed several alternatives. The goal of the analysis was to determine a trail route that provides a safe and enjoyable trail for users, has the least impact on neighboring properties and the environment, and makes the best use of public funds. View the one-page project sheet. Leer los detalles del proyecto en español.
One-Way Alternative Recommended - The Green River Trail North Extension project is constrained by State Route 99, West Marginal Place S., private property, and the Duwamish River. To build a pedestrian/bicycle facility to regional trail standards a unique design strategy is needed. The recommended alignment of the trail includes replacing the northbound drive lane of West Marginal Place S with a regional trail. Southbound vehicular traffic will still be accommodated. This approach includes a roundabout and a turnaround for vehicles at the ends of the reconfigured road. The project will also build sections of a new regional trail separated from roads by a vegetated planting strip. View a typical section of trail.
Several other alternatives were evaluated during the design process.
Design:
Alternative Alignment Analysis (May 2018)
30% Plans (Sept 2023)
Critical Areas Report (2023)
SEPA Checklist (2024)
SEPA Studies:
Conceptual Stormwater Technical Memo (2020)
Figure 1 Vicinity Map (2021)
Figure 2 Critical Areas Report
Hazardous Material Review (2017)
Preliminary Geotech Report (2017)
Preliminary Geotech Stormwater Disposal Evaluation (2020)
SEPA Greenhouse Gas Emissions Worksheets (2023)
Speed Study (2021)
Traffic Study Update (2019)
Public Outreach:
Neighborhood Meeting Summaries: