A new segment of the Lake to Sound Trail is now open in South King County, marking the completion of two-thirds of a 16-mile corridor that will eventually connect Lake Washington in Renton to Puget Sound in Des Moines.

The new trail segment connects the cities of Burien and SeaTac to the existing Des Moines Creek Trail, opening more than seven miles of continuous, non-motorized trail.

Partners have now completed 11 miles of the 16-mile regional trail that connects to four other regional trails, two Sound Transit Link stations, the Sounder, Metro RapidRide A Line, and Sea-Tac International Airport.

“Thanks to strong partnerships and the King County Parks Levy, we’ve completed two-thirds of the Lake to Sound Trail, connecting cities from Lake Washington to Puget Sound with convenient access to high-capacity transit,” said King County Executive Shannon Braddock. “We’re making it safer and healthier for people in South King County to bike, walk, and roll to some of the best destinations our dynamic region has to offer.”

Map of the Lake to Sound trail including segments open for use from Des Moines through SeaTac to Normandy Park

King County Parks built the 2.2-mile Segment C of the Lake to Sound Trail to meet regional trail standards, featuring 12-foot-wide paved surface and two-foot-wide soft shoulders.

To protect sensitive natural areas, the project team installed elevated concrete boardwalks that minimize impacts to wetlands and preserve the site’s natural hydrology — allowing native vegetation to thrive beneath the trail. The project capitalized on the Washington State Department of Transportation’s SR 509 Completion Project by repurposing portions of the old roadway, creating a cost-effective and environmentally responsible trail corridor.

“This segment demonstrates how strategic partnerships and community investment come together to create safe, connected, and inspiring public spaces,” said Warren Jimenez, King County Parks Director. “With fewer rail corridors available for conversion, these are the kinds of bold trail projects we’ll continue to pursue to serve generations to come.”

The project was made possible through a partnership between King County Parks, WSDOT, the Port of Seattle, and the cities of Burien and SeaTac. Funding was generated by WSDOT, a grant from the Washington State Recreation and Conservation Office, and the voter-approved King County Parks Levy.

The completed Lake to Sound Trail will connect five cities – Renton, Tukwila, Burien, SeaTac, and Des Moines – and four other regional trails: Eastrail, Cedar River Trail, Interurban Trail, and Green River Trail.

Lake to Sound Trail is part of Leafline, a Central Puget Sound regional trail network that connects King, Pierce, Snohomish, and Kitsap counties.

“The Lake to Sound Trail is not only a gift to our communities, but to all those who visit here from out of state or around the world,” Des Moines Mayor Traci Buxton said. “Our segment transports you into a wonderland of fern covered logs, small waterfalls, and boulders blanketed with moss. If you visit, keep a look out for an Ewok or a Hobbit!”

The new trail segment is the latest progress for King County regional trails in recent years. King County Parks completed East Lake Sammamish Trail, built a trail bridge connecting Eastrail to Sound Transit’s Wilburton Station in Bellevue, added two trail connections to Marymoor Village Station in Redmond, and added a scenic bridge to Foothills Trail that crosses the White River.