After nearly a month of round-the-clock work to stabilize a massive landslide south of Bellingham, the Washington State Department of Transportation announced that northbound Interstate 5 is scheduled to reopen by 5 a.m. on Thursday, April 16 -- a milestone Whatcom County commuters and businesses have been waiting on since the roadway closed March 19.
The reopening is contingent on final evaluations by geotechnical engineers, who must certify slope stability before lanes open to traffic. Once approved, all lanes between North Lake Samish and Nulle Road will be accessible again for the first time in nearly four weeks. WSDOT's project page has real-time updates on the reopening timeline.
The March 19 landslide deposited thousands of cubic yards of debris onto northbound I-5 near exit 246, forcing the complete closure of the corridor between those two interchanges. That stretch is one of the primary freight and commuter routes connecting Bellingham to the greater Seattle area, and its closure immediately pushed traffic onto alternate routes including Chuckanut Drive and State Route 11, adding significant time to already long commutes and increasing wear on roads not designed for freeway-level traffic volumes.
Over the weekend, crews reached a critical stabilization milestone when they dislodged a large, loose slab of material on the west end of the slide zone. With that section cleared, engineers were able to fully assess the remaining slope. The area now requires anchoring in three locations before engineers can sign off on the reopening. WSDOT crews have been working continuously to complete that work ahead of Thursday's target.
The timeline for this closure was always tied to geotechnical safety, not just debris volume. Stabilizing a hillside directly above an active freeway corridor involves more than clearing rock and soil. Engineers must analyze fracture patterns, assess underlying geology, determine what drainage systems are needed to prevent future saturation-driven movement, and certify that the slope is stable enough that reopening will not create new hazards for drivers traveling below.
Whatcom County's wet winter provided the backdrop for this slide. Washington State is now receiving a federal disaster declaration for the December 2025 floods, which saturated hillsides across the region. The Whatcom County Emergency Management emergency management portal continues to track active advisories for the county.
For local businesses, the closure came at a costly moment. Agriculture, retail distribution, and light manufacturing operations that move freight along I-5 have absorbed four weeks of added cost and delay. Trucking detours through alternate routes add miles and hours to routes that normally move efficiently on the freeway.
The April 16 opening remains conditional. If engineers identify additional instability during Thursday's final evaluation, the timeline could shift. Travelers planning early morning trips north are encouraged to check WSDOT's traffic page before departing, as lane configurations and inspection status may affect the exact opening time.
Expect some congestion near the Samish interchange in the first few days after reopening as drivers filter back onto the freeway. The surrounding local roads should gradually return to normal volumes once the closure lifts.
For anyone still navigating Whatcom County road conditions, WSDOT's real-time travel information page and the 511 traffic line provide current road status across the state highway system.
