At the bottom of Coal Creek Natural Area, the Red Cedar Trailhead on Coal Creek Parkway SE is fenced off. A tunneling machine has been running there day and night since summer. King County's latest project bulletin, sent October 2, says the contractor is "continuing around-the-clock tunneling work at the Red Cedar Trailhead." Trail users are pointed to other entrances: Forest Drive, Red Town, Cinder Mine and "other trailheads."
The City of Bellevue's notice runs longer than the tunneling does. Its Coal Creek Natural Area page says the Red Cedar Trailhead "will be closed through 2031 due to construction by King County." For about the next five years, the creek's lower entrance is a work site. Getting to Coal Creek now means starting near the top, off Lakemont Boulevard SE or Newcastle Golf Club Road, and walking down toward the water.
A Mile of Pipe Under the Trail
The project replaces a regional sewer line that serves Bellevue and Newcastle. The current pipe was built between 1966 and 1991, and King County says it is at maximum capacity. The upgrade adds about 2 miles of new pipe and moves the active line out of Coal Creek's environmentally sensitive areas.
Tunneling is the part going on now. King County's July 16, 2026 bulletin said the machine would start at Red Cedar as early as Monday, July 20, and install about a mile of the new pipe underground. The bulletin warned that people nearby "may feel small vibrations" and expected tunneling to finish by early 2027. The county's short video of the machine is titled "Building a new sewer line 120 feet underground?" The project map shows the new trunk line tying into the local and regional systems at a North Connection Area near 119th Avenue SE and I-405, with a temporary shaft along the tunnel route.
Tunneling is one phase of a longer build. King County's project overview says construction began in 2025 and is expected to be complete by 2030, subject to change.
| Milestone | Date | Source |
|---|---|---|
| Tunneling start at Red Cedar | As early as July 20, 2026 | King County, July 16 bulletin |
| Tunneling complete | Expected early 2027 | King County, July 16 bulletin |
| Overall construction complete | Expected by 2030 | King County project overview |
| Red Cedar Trailhead closure | Through 2031 | City of Bellevue park page |
When the tunneling ends in early 2027, the trailhead will still be closed.
The Trail Now Starts at the Top
Bellevue's park page puts the Coal Creek Natural Area trail system at 4.5 miles and lists the Cinder Mine Trailhead at 15484 Newcastle Golf Club Road as its main address. The city's Hikes page places Red Town Trailhead on Lakemont Boulevard SE, just south of Forest Drive SE. King County says parking is available at Cinder Mine, Red Town and the Coal Creek Family YMCA. The YMCA is at 13750 Newcastle Golf Club Road. The Washington Trails Association's Coal Creek page also lists the YMCA and SE 60th Street accesses as open.
| Entrance | Where | Parking noted by King County |
|---|---|---|
| Red Town | Off Lakemont Boulevard SE, just south of Forest Drive | Yes |
| Forest Drive | Forest Drive SE | Not listed |
| Cinder Mine | 15484 Newcastle Golf Club Road | Yes |
| Coal Creek Family YMCA | 13750 Newcastle Golf Club Road | Yes |
| SE 60th Street | Listed as open by WTA | Not listed |
| Red Cedar | Coal Creek Parkway SE | Closed through 2031 |
King County says the Red Cedar Trailhead is closed to all public use during construction, with a trail detour built around the work area, and asks trail users to follow the detours and stay out of fenced areas and off the creek bank. A walk that used to end at a parking lot on the parkway now ends at a fence, so plan an out-and-back from one of the upper entrances.
What the Walk Down From Red Town Passes
The lower trailhead closed, but the trail's history is at the upper end. The city's park page describes Coal Creek Natural Area as a place where "you can almost hear clanging coal cars" in the second-growth forest and asks visitors to look for traces of the early coal industry along the trail. Visit Bellevue's history walk write-up dates the area's coal-mining era from 1863 to 1963.
According to WTA's route description, a walk from Red Town passes these, in this order:
- A mining-history kiosk near the start
- A mine airshaft
- A short interpretive trail
- The footing of a former locomotive turntable
Starting at Red Town, the history comes first and the deeper creek walk comes after. The fencing at Red Cedar marks the far end of a walk that runs downstream.
Fall on the Creek, From the Record
Coal Creek is a salmon stream. The City of Bellevue's stream monitoring memo says the Coal Creek watershed provides spawning and rearing habitat for Chinook, sockeye and coho. The city has monitored spawning in select Bellevue streams since 1999, and current survey work focuses on Coal Creek.
In the city's 2023 spawner survey, surveyors recorded live adult Chinook in Coal Creek from September 20 to October 6 and live adult coho from October 2 to November 21. Those dates describe one past season, and returns change from year to year. If this fall follows a similar pattern, late October falls inside the coho window recorded in 2023.
The closure affects salmon watching too. In 2021 the City called out the Red Cedar Trailhead as a particularly good spot to see spawning salmon. That spot is now behind the construction fence. Any fish seen this season will be seen from the main trail. Bellevue's guidance for salmon streams is to stay on the main trail, keep dogs leashed and out of the water, and leave live and dead salmon alone.
What Comes Back After the Closure
The same project that closed the lower entrance is planned to rebuild it with more access than it had before. In its April 9, 2025 announcement, King County said the rebuilt Red Cedar Trailhead will keep its general look while adding ADA-level access, benches, a wider surfaced trail suitable for wheelchairs and strollers, and a trail with Braille and tactile signs.
The creek itself is part of the plan. King County says much of the old pipe will be decommissioned in place, sections running through the creek will be removed, and native plants and woody debris will go in to restore ecological function. The same release says the project will restore and expand existing wetlands and add fencing to protect the native understory and tree canopy that keep the creek cool for salmon. The county's project sign tour adds evergreen tree planting and slope and stream bank restoration that protects the pipes and trail while keeping natural stream flows for fish. The county announced that the project is the first wastewater infrastructure project to earn Salmon-Safe certification. The certification is valid for five years and is reviewed every year.
When Red Cedar reopens, the lower end of the creek is planned to be the most accessible entrance in the natural area. Until then, the only way in is from the top.
Coal Creek Parkway While the Machine Runs
The work also shows up on the road. The July bulletin listed a northbound single-lane closure on Coal Creek Parkway SE near the Red Cedar Trailhead from 10:30 a.m. to 5 a.m., seven days a week. The lane stays open from 5 a.m. to 10:30 a.m. to reduce morning commute impacts. The October bulletin describes on-and-off single-lane closures around the work areas "only when needed," with drivers and cyclists sharing a lane through the zone.
These hours change. The City of Bellevue's traffic advisories page is typically updated on Thursdays, and the city notes that construction schedules often shift. Check it before a weekday drive past the work zone. For project questions, King County runs a construction hotline at 425-537-7195 and an inbox at [email protected], and you can sign up for the project's email updates.
A multi-year public project near your street can affect the timing of a sale and the questions buyers ask. If you're planning a move around Lakemont, Somerset or Newport Hills between now and 2031, Carissa Saffel can help you work out how the construction calendar fits your own. Schedule a Consultation when you're ready to talk it through.
