Update: May 5, 2026
We executed an emergency contract and began work Tuesday, May 5. This work is to clear a rockslide along State Route 20/North Cascades Highway near Diablo Lake.
This is the first of two repair projects needed to reopen SR 20. Heavy rains in December and March damaged several sections of the scenic highway that connects Skagit and Okanogan counties.
SR 20 has been closed from the west side near milepost 130 since a March 17. The closure is due to a rockslide near milepost 131. People can still reach Colonial Creek Campground during the closure, but no one is allowed between the campground and Porcupine Creek (milepost 156).
Interwest Construction Inc. from Burlington will do the emergency repairs on SR 20. You may remember them as the crew that stabilized the slope after a slide closed northbound I-5 south of Bellingham.
Though each slide is different and presents its own challenges, their basic goals at the slide along SR 20 will be the same:
- Removing loose rocks and debris from the slope (called scaling)
- Drilling holes and using long rock dowels to anchor and stabilize the slope
- Clearing debris
- Making any needed repairs at the site
More repairs remain
Damage between mileposts 142 and 148 still needs to be repaired before SR 20 can open for the summer. This repair will be addressed by a second contract. This area, which is beyond the seasonal closure gate at Ross Dam Trailhead (milepost 134), was severely damaged in multiple areas during December’s atmospheric river weather event.
We are exploring all options to secure the proper permits and permissions and get a contractor in place to begin this emergency work. We plan to reopen North Cascades Highway as quickly as possible.
Once work is going, we expect crews to work 24 hours a day, seven days week at both locations when it is safe to do so.
The time of reopening will depend on what crews find and how difficult the repairs are. Sometimes, crew members and engineers may need to change their plans if they find new damage. Once a contractor is identified and construction begins on the second emergency project, we’ll have a better idea of the schedule.
We have been prioritizing repairs since snow receded in the damaged areas between mileposts 142 and 148. We’re continuing to focus on reopening North Cascades Highway as quickly as it is safe to do so.
What to expect
SR 20 is an active work zone between mileposts 130 and 156. It is not safe for people to enter the area, even for hiking, biking, or camping. The electronic message boards at the closure points are there for your safety. While some of the damage can be seen, much of it is hidden, including areas where the roadway is undermined beneath the surface and slopes above remain unstable.
Original: posted April 30, 2026
Each year, people across Washington look forward to the reopening of the North Cascades Highway. It’s more than just a road; for many it’s a seasonal, scenic destination and an important link for communities and businesses on both sides of the Cascades.
This year, that reopening will take longer than any of us would like.
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| SR 20/North Cascades Highways remains closed after it suffered significant damage over the winter. |
What you need to know
- SR 20 remains closed due to significant damage from winter storms and a spring rockslide.
- Beginning Thursday, April 30, we will open limited access on the east side up to milepost 156.8 at Porcupine Creek with a closure at the gate to the west.
- We do not yet have a timeline for fully reopening the highway.
This partial opening allows people to access more of the corridor from the east while keeping the active work zone between mileposts 156 and 130 closed for safety.
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| SR 20 remains closed between Colonial Creek Campground (milepost 130) and Porcupine Creek (milepost 156) while repairs are made to the North Cascades Highway. |
What happened
This winter brought a series of historic atmospheric river events that caused major damage to the roadway. In December 2025, heavy runoff overwhelmed culverts near milepost 145, sending water across and beneath the highway. That erosion undermined sections of pavement and crews discovered that in some places, the roadway is no longer supported underneath.
In March, a separate rockslide near milepost 131 covered the roadway and left the slope above the highway unstable.
Together, these events created multiple, complex repair locations across several miles of SR 20.
Why this work takes time
We’ve heard the frustration and the concern that this highway isn’t being prioritized. We know people have seen us move quickly on other highway repairs across the state, and that can make this situation feel different.
The reality is that every incident is different, and every repair comes with its own set of conditions. In some cases, we’re able to use emergency contracting methods that allow work to begin immediately and be completed in a short window. Those are typically situations where repairs can be done in 30 working days or less.
The good news is, we can utilize a 30-day emergency contract to stabilize the slope and clear debris from the rockslide at milepost 131. By splitting the SR 20 repairs into two parts, we can select a contractor and get started on that work the week of May 4.
The unfortunate news, is the second part of the repairs between milesposts 142 and 148 is not one of those situations. Damage here includes:
- Three locations where the embankment supporting the roadway needs to be rebuilt
- More than 1,000 feet of lane that has been undermined or collapsed
- One to 2 miles of damaged or collapsed asphalt shoulder
- Two to 3 miles of ditch line that needs to be repaired
- More than 1,000 feet of damaged guardrail and/or concrete barrier
- Approximately 15 culverts that are damaged or covered by debris
- Several places where specialty crews must scale the slope to remove loose hanging rock that it at risk of coming loose and falling
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| A March 17 rock slide near milepost 131 forced SR 20 to be closed in both direction near Colonial Creek Campground. Slope stabilization and debris clearing are expected to begin in this area shortly. |
Given the extent of damage, this work cannot be completed within 30 days, even if crews were working around the clock. Because of that, we are required to use a different contracting approach, which includes developing plans and allowing contractors to bid on the work.
From there, the work itself includes rebuilding sections of roadway where the ground beneath the pavement has washed away, stabilizing more slopes above the highway, repairing drainage systems and replacing damaged barriers and guardrail.
There are also factors that influence how quickly we can move:
- Federal funding requirements: Many large repairs like this rely on federal funding, which requires environmental review, documentation and specific contracting processes.
- Permitting: Work in and around streams and sensitive areas requires permits and coordination before construction can begin.
- Access and conditions: Winter weather and avalanche risk delayed access to the site, limiting early assessment and design work at some of the damaged areas.
Across Washington, we’ve invested tens of millions of dollars repairing highways damaged by recent flooding events. SR 20 is part of that larger effort, and we are working to move this project forward as quickly as we can while meeting those requirements.
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| Winter weather and avalanche risk prevented access to the washout areas along SR 20 between mileposts 142 and 146 until mid-March, but our engineers have been busy assessing the area and designing repairs since. |
A note about environmental review — and why it matters here
You may hear us reference environmental review as part of this work. That includes a federal law called the National Environmental Policy Act, or NEPA.
In simple terms, NEPA requires us to take a close look at how a project might affect nearby streams, wildlife and surrounding lands, especially when federal funding is involved.
And on SR 20, that matters. This corridor runs through one of the most scenic and environmentally sensitive areas in Washington. The same things that make this drive so iconic, like the mountains, rivers, forests and wildlife, are also what require us to slow down and do this work thoughtfully.
Before we can begin repairs in certain areas, we need to evaluate impacts, coordinate with partner agencies and obtain the necessary permits and approvals. That work happens alongside engineering and design, but it does add steps.
It’s part of the responsibility that comes with maintaining a highway in a place like this, making sure we don’t just reopen the road, but protect the place that makes it worth the drive. Fortunately, we also can finish some of these steps over the next few weeks while crews are out scaling the slope and dislodging loose rocks near milepost 131.
By the time that work finishes, we’ll hopefully be ready to begin repairs further up the road.
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| The closed section of SR 20 includes unstable slopes, damaged roadway and areas where the ground beneath the pavement has been washed away. These conditions aren’t always visible from the surface. |
Recreation impacts and what to expect
Recreation access along SR 20 was limited this winter due to the floods, and it will continue to be limited this spring and into early summer as repair work moves forward.
We also know one of the biggest questions people have is timing. Will it be open by Memorial Day? By my birthday? In time for the annual family roadtrip? The honest answer right now is: we don’t know yet.
We recently brought several contractors up to the site so they could see the full scope of the damage and ask questions before submitting bids. Once a contract is awarded, the work still will take several weeks to complete. And during that time, this will be an active construction zone.
The closed section of highway includes unstable slopes, damaged roadway and areas where the ground beneath the pavement has been washed away. These conditions aren’t always visible from the surface.
We also know it can be easy to look at a rockslide and think it’s just a matter of clearing debris off the road. In reality the visible rocks are often just one part of the problem. In several locations, culverts are damaged or blocked, drainage systems have failed, and sections of roadway are undermined beneath the pavement. Repairs go far beyond clearing what you can see. They require rebuilding the structure that supports the road itself.
Because of that, there is no safe way to allow access through the work zone. And that means no biking, hiking or camping in the closed section. These are complex, heavy construction operations in a narrow corridor, and there isn’t room to safely separate the public from the work.
Emergency access through this area is limited, and keeping the corridor clear allows construction crews and emergency responders to move quickly if needed.
Until that work is complete, this area remains closed so crews can do the job safely and fully, not just quickly.
Looking ahead
We understand how much this reopening matters. For many, it marks the start of summer. This year, the work behind the scenes is bigger than usual and so is the effort to get it done right. Our goal is the same as yours: reopen the North Cascades Highway as quickly as possible.
