Upper Mill Creek Road Improvement Project Construction Update

As part of the ongoing Upper Mill Creek Canyon Road Improvement Project, the upper roadway reclosed to all public access on March 15 to allow construction to resume for the 2026 season.

As with the previous construction season, there will be no public access on the upper roadway beginning at the Terraces. This closure applies to walking, biking, and driving on the road.

Access to the upper portions of the canyon will continue to be available via designated trails and trail connections. We’ve worked closely with our partners to maintain as much trail access as possible during construction.

As a Reminder:

Access and Parking Restrictions: During construction, motor vehicle access in the upper canyon will be closed to the public. A construction access gate and field office trailers will be located near the Terraces Picnic Area to support construction staging.

Construction Timeline: Work is scheduled to resume on March 15th and continue through the summer. We anticipate that construction will be completed before winter recreation resumes in late 2026. Specific dates may shift slightly depending on weather and ground conditions.

Visitor Guidance: Canyon users are encouraged to plan ahead and carpool. Remember that weekends and early mornings may be busier, so flexibility and patience are appreciated.

Trails Remain Open

While the Upper Canyon roadway will again be closed to all vehicles, bikes, and pedestrians during construction, trail access will remain available via connections from the lower canyon. Popular routes like the Pipeline Trail and Upper Pipeline Trail will continue to offer access to most of the upper canyon’s recreation areas.

A map of open trails and connections is included below to assist with planning your visit. Clicking the map will direct you to the full-resolution version on our website.

For more information and continuous updates, visit our project page at slco.to/FLAP.

We appreciate your understanding as we aim to finish these necessary improvements.

Our shared goal is to ensure Mill Creek Canyon remains a safe, sustainable, and welcoming destination for years to come!