NB I-5 closure enters third week as crews stabilize Bellingham mudslide
Apr 6, 2026, 12:30 PM
A photo of the mudslide clean up efforts on northbound I-5 near Bellingham. (Photo courtesy of the Washington State Department of Transportation)
(Photo courtesy of the Washington State Department of Transportation)
A massive mudslide near Bellingham has closed all northbound lanes on I-5 for more than two weeks. The initial closure on March 19 caused a steady three-mile backup approaching the detour route at N. Lake Samish Road (milepost 246).
The slides carved a debris field more than 100 feet wide between mileposts 248 and 249 and sent an estimated 2,000 to 3,000 cubic yards of debris down a 60- to 80-foot slope toward northbound I-5 lanes below.
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WSDOT crews nearly finished drilling, anchoring steel dowels to stabilize 80-foot slope in Bellingham
On Sunday, Washington State Department of Transportation (WSDOT) crews continued drilling on the top band of the slope and anchored steel dowels to stabilize it, WSDOT announced.
UPDATE 4/5: Though plans could change as we continue to assess, drilling on the top band of the slope is almost finished. Crews are anchoring steel dowels to stabilize the slope.
NB I-5 remains closed after 3/19 slide. Continue to use alternate routes & obey speed limits. https://t.co/VaUn5TfcaV pic.twitter.com/tF33J6IOcB
— WSDOT North (@wsdot_north) April 5, 2026
The work on drilling and placing rock dowels to stabilize the slope began on March 31, but WSDOT believes this work is “almost finished.”
“Geotechs constantly evaluate and adjust plans based on what they see, so this process takes time and precision,” WSDOT stated.
As of Saturday, WSDOT had drilled more than 1,000 linear feet for 15- to 25-foot steel dowels to stabilize the slope.
On April 1, the department noted that something big had happened: a “bus-sized” rock in the middle of the landslide had been split in two.
UPDATE 4/1: Something big happened today – like “bus-sized.” We split the large rock in the middle of the slide. We’re also continuing to drill & anchor steel dowels to stabilize the slope above.
NB I-5 remains closed at exit 246. Please follow proper zipper merge etiquette. https://t.co/aiz21OlKp3 pic.twitter.com/NfS5IJrIKL
— WSDOT North (@wsdot_north) April 2, 2026
High winds initially stalled cleanup efforts after March mudslide
Days after the landslide, inclement weather, including high winds, stalled WSDOT crews’ cleanup efforts. The winds denied WSDOT from safely beginning its scaling, though they continued working in other areas and attempted scaling the following day.
Work began with contractors clearing trees and debris from the freeway. Crews worked around-the-clock to reopen I-5 as quickly and safely as possible, according to WSDOT. Due to safety concerns with the unstable slope, some work must take place during daylight hours.
Roughly 2-3,000 cubic yards of material were blocking the road immediately following the landslide. WSDOT noted that one dump truck can fit 16 yards of material per run.
UPDATE 8:30AM: Crews just sent these photos of NB I-5 south of Bellingham where all lanes remain closed due to slide activity. Geotechs will be on site this AM.
Roughly 2-3000 cubic yards of material is blocking the road. For context, the avg. WSDOT dump truck carries 16 yards. https://t.co/LqgqUQEj2w pic.twitter.com/h8cS4gW977
— WSDOT North (@wsdot_north) March 20, 2026
Due to the geology of the area, this location is prone to slides. WSDOT maintenance crews routinely do hazard tree removal and vegetation management, and clear drains and culverts to help reduce the chances of larger slides.
A barrier was also installed along this stretch of I-5 to catch many smaller slides. But sometimes heavy rain events, such as the recent atmospheric river, can trigger larger slides with more debris, forcing highway closures.
WSDOT selected Interwest Construction Inc. to perform the emergency work.
NB I-5 remains closed. Travelers should expect delays throughout the area and are urged to obey speed limits.
“We want to remind people that local roads are NOT freeways,” WSDOT stated. “Please follow the signs & the speed limit.”
A freight detour is set up for eastbound SR 20 to northbound SR 9 to westbound SR 542.
Contributing: Nate Connors, KIRO Newsradio
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