Drivers heading northbound on Interstate 5 into Bellingham this week should expect delays and lane reductions during overnight hours through Thursday morning, September 17. The Washington State Department of Transportation is closing the Alger/Lake Samish Road on-ramp and reducing I-5 to a single lane in both directions as part of an ongoing fish passage restoration project near Lake Samish.
What the Closures Look Like This Week
The Alger/Lake Samish Road on-ramp to northbound I-5 is closed from 8 p.m. to 5 a.m. starting Monday, September 14, and continuing through Wednesday morning, September 16. Drivers who would normally use that on-ramp are directed to follow a signed detour to the Nulle Road on-ramp to access northbound I-5.
Starting Tuesday night, September 15, and running through Thursday morning, September 17, both directions of I-5 are reduced to a single lane during the same overnight window of 8 p.m. to 5 a.m. That means drivers heading both northbound and southbound will be merging to one lane for a stretch of the highway south of Bellingham during those hours.
For commuters, late-shift workers, and anyone traveling through the area in the evenings or early mornings, the practical effect is that travel times on I-5 near Lake Samish will be slower and less predictable than normal. WSDOT recommends building extra time into any overnight travel plans through the area this week.
The Project Behind the Closures
The work is part of WSDOT's project to correct 17 fish passage barriers near Lake Samish. Crews are restoring natural habitat along a tributary to Friday Creek, which flows through the area before reaching the lake. The goal is to remove or modify structures, typically older culverts or undersized pipes, that prevent fish from swimming upstream to access spawning habitat.
Fish passage barrier removal is one of the more consequential environmental commitments associated with highway infrastructure in Washington State. Under a long-standing federal court order stemming from treaty rights of Pacific Northwest tribes, the state is required to fix thousands of culverts on state highways that have blocked salmon and steelhead migration for decades. Washington has been working through a prioritized list of those barriers for years, and the Lake Samish area project is one of the local manifestations of that statewide effort.
Friday Creek, the tributary being restored through this project, is a small stream but part of a larger network of waterways that connect to Lake Samish. The lake itself sits in a narrow valley between the Chuckanut Mountains and the foothills east of Bellingham, and it drains into Samish Bay to the south. Healthy fish runs in the lake's tributaries support both the broader Samish watershed ecosystem and the recreational fisheries that Whatcom and Skagit County residents use.
Lake Samish Road and the Surrounding Area
The Alger/Lake Samish interchange is located at approximately milepost 240 on I-5, a stretch of highway that sees heavy traffic from Bellingham commuters, travelers heading to and from Seattle and Vancouver, and truck freight moving through the corridor. The Lake Samish exit provides access to the Alger community and to Lake Samish Road, which runs along the western shore of the lake and connects to Chuckanut Drive further south.
The Nulle Road detour on-ramp, to which drivers are being redirected during the on-ramp closure, is the next available northbound access point and adds a modest amount of time to trips that would otherwise use the Alger on-ramp. Drivers unfamiliar with the area should watch for WSDOT signing, which should direct traffic through the detour route.
This is not the first recent road work affecting I-5 in the Bellingham area. Earlier this month, overnight paving work closed portions of East Badger Road in Lynden, and the State Route 546 corridor near Lynden also saw nighttime closures for pavement work. WSDOT typically schedules disruptive lane reductions and on-ramp closures during overnight windows to minimize the impact on daytime traffic volumes, which on I-5 near Bellingham are substantially higher.
Planning Around the Closures
If you regularly commute on I-5 through the Lake Samish area, the simplest adjustment for this week is to finish your travel before 8 p.m. or wait until after 5 a.m. if you have flexibility. For drivers who need to travel during the overnight window, using the Nulle Road on-ramp for northbound access and anticipating a single-lane slowdown on the mainline starting Tuesday night will help manage expectations.
Real-time traffic conditions on I-5 near Bellingham can be checked through WSDOT's 511 traffic information system or the agency's mobile app, which shows camera feeds, travel times, and active alerts for the corridor. For a broader look at road conditions across Whatcom County this week, including earlier coverage of closures on Alm Road and other routes, prior reporting covers how WSDOT has managed I-5 disruptions near Bellingham in recent months.
