Red Cedar Trailhead Stays Closed Through 2031. Where Do Somerset's Coal Creek Walkers Start Now?

King County's September update on the Coal Creek sewer project gives a date that is easy to remember. Tunneling is expected to finish by early 2027. The City of Bellevue's page for Coal Creek Natural Area gives a much later date. It says the Red Cedar Trailhead will be closed through 2031.

Both are correct. They describe different milestones. If your usual walk started at the Red Cedar lot on Coal Creek Parkway SE, think of your detour as your route for the next several years. The good news is that the four trailheads King County recommends instead are very different from each other. Each one suits a different kind of outing.

Three dates, three different milestones

The county's online open house lays out the full schedule. Planning began in 2016, construction started in 2025, and the county expects to complete construction by 2030. It adds that the schedule may change. The tunnel is one piece of that. The tunneling machine went in at the Red Cedar Trailhead in July and is digging about a mile of new pipe underground, around the clock.

When the tunneling machine reaches its exit pit near I-405, the job is not over. Red Cedar is also the site of the trailhead restoration that comes later. So the most useful question for now is which entrance makes sense for which walk, not when Red Cedar reopens.

Forest Drive is the nearest entrance, and the one with the least parking

The Forest Drive access sits east of the intersection of Coal Creek Parkway SE and Forest Drive SE, and it opens onto the natural area's trail network. King County flagged the downside early. In its May 2025 closure notice, the county said the Forest Drive detour had been built ahead of time and that parking there was limited. The current open house says the same thing in its own way. It lists parking at Cinder Mine, Red Town, and the Coal Creek Family YMCA, and leaves Forest Drive off that list.

That shapes how the entrance works best. It suits a walk where you don't have to compete for one of a few parking spaces. From Forest Drive you can head onto the Coal Creek Trail and the Primrose route. One Washington Trails Association member logged 4.44 miles and 771 feet of gain on a Forest Drive out-and-back using both. That is one hiker's track, not an official distance. Still, it gives a sense of what a solid weekday loop from this side looks like.

The detour itself has a local story. King County worked with the City of Bellevue's Well-KEPT program, a summer youth employment program, to build the trail detour around the work area.

Recent trip reports show what the ground looks like right now. A WTA hiker out on September 3, 2026 described a section of Primrose rerouted away from the creek, new stairs, and a nearby bridge that was still roped off. A September 26 report noted a large fallen maple and branches about 1,500 feet south of a neighborhood connector's junction with the Coal Creek Trail. These are reports from individual hikers, not agency notices, and conditions may have changed since. Dogs are allowed on leash on the Coal Creek Trail.

Pick the trailhead by the walk you want

Getting to the other three entrances means driving out of the neighborhood. Each one gives you something Forest Drive doesn't.

Red Town, for history and a waterfall. Red Town is on Lakemont Boulevard SE, about 3.1 miles south of I-90 Exit 13. The large lot holds about 35 cars and has portable toilets. WTA notes that weekend spaces can fill and that there is no potable water. The short Red Town Meadow loop is 1.5 miles round trip with 150 feet of gain. It follows the Wildside, Red Town, Rainbow Town, and Steam Hoist trails past the Ford Slope mining exhibit, a sealed mine entrance, and the foundations of the old steam hoist. Red Town is also the practical starting point for Coal Creek Falls. The route by way of Cave Hole is 2.5 miles round trip with 416 feet of gain. The falls drop 28 feet and are fed by runoff, so they usually look best in the rainy winter months and are often dry by summer. In October that timing starts to work in your favor.

Cinder Mine, for the official address and a short drop to the creek. The city lists the natural area's contact address as Cinder Mine Trailhead, 15484 Newcastle Golf Club Road, Newcastle. The city also puts the natural area's trail system at 4.5 miles. From the small parking area, the Cinder Mine Trail runs 0.3 mile down to the Coal Creek Trail. North Fork Falls is about 0.2 mile farther along the creek.

Coal Creek Family YMCA, for a parking lot on a familiar road. The YMCA is at 13750 Newcastle Golf Club Road, Newcastle. King County names it as a trail access point with parking. The materials don't spell out terms for parking after hours or for non-members, so check with the YMCA before you make it your regular start.

One trade-off applies to every option. WTA's standard Coal Creek Trail figure is 6.0 miles round trip with 550 feet of gain. With work areas along the trail closed, that full corridor toward the Red Cedar end isn't a continuous walk right now. For now, plan on shorter out-and-backs from whichever end you choose.

What is happening on the parkway in the meantime

Driving to Red Town or Newcastle Golf Club Road means passing the work zone, and the lane closures run on a published schedule:

• Northbound near Red Cedar: one lane closed from 10:30 a.m. to 5 a.m., seven days a week, during tunneling. It stays open from 5 to 10:30 a.m. to ease the morning commute.
• Southbound: lane closures permitted on weekdays, 6 a.m. to 3 p.m.
• Northbound near Factoria Boulevard SE: a lane closure permitted on weekdays, 10:30 a.m. to 7:30 p.m.

Flaggers direct traffic, and drivers and cyclists share a lane through the work area. The county has also put construction monitoring devices in the right-of-way along the tunnel route. Each is a small solar-topped unit on a concrete block, and the county asks people to leave them alone. A second detour starts this month a little to the north. For the Mountains to Sound Greenway Trail project, SE 36th Street drops to one westbound lane between 142nd and 150th Avenue SE from the first week of October through the end of 2027. Eastbound traffic is detoured to SE Eastgate Way.

What the long closure is buying

The reason for all this is the creek. The existing sewer line follows Coal Creek, and floods have repeatedly scoured the banks around it. The most recent bank repair was in August 2020. The new pipe goes deep underground, away from the banks and the salmon habitat.

When Red Cedar does reopen, the county says it will be restored to its existing condition, with some added improvements for accessibility and education. Those will build on the accessibility upgrades Bellevue made there in 2015. More than 1,400 new trees will be planted, along with a native understory. A retaining wall and streambank restoration will protect a steep, narrow stretch of trail where the creek bends toward it.

Several dates on this fall's calendar connect to these trails:

• October 17: Bellevue Arbor Day volunteer planting of native trees and shrubs at Lewis Creek Park, 9 to 11 a.m., registration required.
• October 19: The Newcastle Trails annual meeting, which lists a planned Coal Creek branch trail and bridge near the Milt Swanson parcel.
• October 24: The next walk of the Somerset Community Association's teen-organized Clean Up Crew, with bags and gloves provided.
• October 31: The Cougar Mountain Trail Run Series at Sky Country Trailhead, supporting King County Parks.

For questions about the work itself, King County's construction hotline is 425-537-7195, or you can email [email protected].

A project that runs through 2031 is the kind of detail worth knowing early if you're thinking ahead about your own home near Coal Creek Parkway. If you'd like to talk about how the timeline lines up with your plans, I'm happy to go over it with you. Ankush Bharti. Let's Connect.