Walk the Centennial Trail through Machias this month and you will hit a stretch where the asphalt gives way to gravel shoulder, orange signage, and a flagger waving cyclists onto S. Machias Road itself. Most people assume this is a temporary inconvenience that clears up once the work crews pack up in the fall. It is not quite that simple. What is happening on this stretch of road right now is the first of two changes to how the trail crosses this corridor, and the second one does not arrive until next spring.
Snohomish County Surface Water Management, a division of the Department of Conservation and Natural Resources, is in the middle of replacing three culverts along S. Machias Road near 2310 S. Machias Road. The largest of the three carries Williams Creek directly under the roadway. Because the new structures need more room than the old ones, the county is also raising part of the road and installing guardrail. To do that work, S. Machias Road between Machias Cutoff Road and Dubuque Road has been under a full 24/7 closure since July 6 at 8 a.m., and it stays that way through October 1 at 5 p.m., according to the county's own roads update. The contractor on the job is Earthwork Solutions. The Snohomish County Tribune confirmed the same closure in its July 8 coverage, describing drivers being detoured off the road for the culvert work through September.
While cars are locked out of that segment, the county has rerouted the Centennial Trail directly onto S. Machias Road for the duration. That is the version of the story most trail regulars already know, because it is the thing standing between them and their normal route.
Two Projects, Not One
Here is the part that tends to get lost. The culvert work wrapping up this fall is a separate undertaking from a second project already approved for the same intersection down the road at Dubuque Road.
| Culvert Replacement (underway now) | Dubuque Road Roundabout (planned) | |
|---|---|---|
| What changes | Three culverts replaced, road raised, guardrail added | Single-lane roundabout with a southbound bypass lane |
| Where | S. Machias Rd between Machias Cutoff Rd and Dubuque Rd | S. Machias Rd and Dubuque Rd intersection |
| Trail impact | Trail rerouted onto S. Machias Rd during construction | Trail crossing permanently relocated about 300 feet |
| Timing | July 6, 2026 through October 1, 2026 | Proposed for spring 2027 |
The culvert project is about fish passage. The roundabout project is about traffic safety and trail crossing design. They happen to sit on the same short run of road, which is why it is easy to mistake one for the other, or to assume that once the detour signs come down this fall, the trail goes back to exactly where it was before.
It does not. It goes back to where it was for one winter, and then the actual crossing point moves.
Why the County Is Digging Up This Particular Stretch
The reason for the summer closure has nothing to do with traffic counts or subdivision growth. It is about fish. Williams Creek, which the largest of the three culverts carries under S. Machias Road, supports chum salmon, coho salmon, steelhead, resident trout, and cutthroat trout. The county's project page states that replacing the undersized culverts will open access to more than 7,000 feet of upstream fish habitat that the current structures restrict. That is a meaningful stretch of stream for species that have to move through this corridor to spawn, and it explains why the county chose a full closure and a raised roadway rather than a lane-shift or a weekend detour.
What Changes Next Spring
The second project, the roundabout at S. Machias Road and Dubuque Road, has already been through five design alternatives, and the county settled on a single-lane roundabout with a southbound bypass lane. Public Works expects the work to reduce delays during morning and evening peak hours and to improve safety for left-turn movements at an intersection that currently has neither.
For trail users, the relevant detail is the crossing itself. The new design shifts the Centennial Trail crossing at Dubuque Road roughly 300 feet from where it sits today. The county has issued a formal finding that this relocation qualifies as de minimis under Section 4(f) of the federal Department of Transportation Act, meaning it does not adversely affect the features that make the trail eligible for that protection. In plain terms, the shift is small enough that federal reviewers signed off without requiring a full environmental impact statement. The county has also committed to permanent safety upgrades at the new crossing, including increased sight distance for drivers, a HAWK beacon, and a refuge island for people on foot or on bikes crossing mid-intersection. During construction, the county says the trail will stay open with temporary detours and signage rather than closing outright, which is a different approach than the full closure now underway on the culvert project.
That project is currently proposed for spring 2027, which puts it roughly six months after this year's culvert work wraps. Anyone who assumes the fall reopening is the end of the story is only getting half of it.
What This Looks Like on the Ground
None of this changes the character of Machias day to day. It is still the kind of place where a stop at Machias Grocery for gas and something out of the deli case counts as an errand, and where a Contos Pizza order is close to a standing tradition for the households near the trailhead. The Machias Trailhead itself, a replica of the railroad depot that served this stretch of the Seattle, Lake Shore and Eastern Railway line in the late 1890s, still has its restrooms and covered picnic area open, and it remains the natural turnaround point for a lot of the walking and riding that happens on this section of trail.
What is different this summer is the texture of that walk or ride once you get past the trailhead and head toward Dubuque Road. Instead of the usual paved trail bed, you are sharing pavement with construction traffic and following signed detours onto the road itself for a few hundred yards. That ends October 1, at least for this phase. Then, sometime in the following months, expect a second round of temporary detours and signage as the roundabout project gets underway, this time reshaping where the crossing sits for good.
For a neighborhood built around quiet lots, dog walks, and a trail that most residents treat as an extension of their own yard, that is worth knowing before you plan your route around it. It also says something about how this corner of Snohomish County actually gets built out. The infrastructure here does not arrive all at once. It comes in phases, tied to specific projects with specific reasons, and reading the county's own project pages closely is often the only way to know what is temporary and what is about to become permanent.
If you are watching Machias for reasons that go beyond a Saturday walk, whether you are weighing a move here or already own along this stretch of trail, it helps to have someone tracking these details as they unfold. Tanya Mock Real Estate keeps an eye on the small changes that shape daily life in Snohomish County neighborhoods like this one. Let's Connect if you would like to talk through what any of this means for a property near the trail.
