Washington State Department of Transportation maintenance crews were to begin clearing the scenic highway today from the Diablo side of the gate.
On Monday, April 9, crews from the eastern, Mazama, side will start working and the two will eventually meet in the middle. This process usually takes four to six weeks but can last longer if spring snow falls or go faster if warm spring temperatures speed up snowmelt.
Once crews clear the snow, they’ll need to assess the road for any winter damage, replace guardrail and signs that were removed during the closure and clear areas of rocks and other debris. Once that work is complete, crews will open the gates to vehicle traffic.
“Like most of our neighbors, we’re excited for the spring season and the fishing and other events that come with it, said WSDOT Twisp Maintenance Supervisor Don Becker. “We want to get this stretch cleared as quickly as we safely can so everyone can start enjoying seasonal activities along the highway.”
During a March 20 assessment trip, WSDOT avalanche and maintenance staff found nine feet of snow near Rainy Pass and deep snow levels on Liberty Bell avalanche chutes. Crews will watch the snow pack on some avalanche chutes that could slide as spring temperatures increase. In other areas, there is less snowpack than we often find, which could help in the clearing process.
Last year the clearing work started April 10th and the reopening wasn't until May 16th, well past the fishing season opener and Winthrop's 49er' Days Festival. Most years warmer temperatures allow the clearing to start before the end of March and the opening comes in 4 to 6 weeks by late April or early May. Don't expect an early reopening this year.
As noted, the snow on the road is only part of the picture. Many of the measurements below avalanche chutes were on par or less than an average year, but some of the chutes had released snow and their depth far exceeded the norm. Examples: Cutthroat Ridge #4 had 10 feet this year, but only 5 last year. CR#6 on the other hand had 13 feet this year compared to 25 feet measured during last year's assessment. Liberty Bell #3 had 50 feet this year and 35 last year, while Liberty #1 only had 20 feet of snow below it on the road this year compared to last year's 45 feet.
The weather and temperatures will determine when the snow still in the avalanche chutes comes down, but the assessment did reveal there's a persistent weak layer in the snow higher up in the chutes in zones from Cutthroat to the Beebe and Ruby zones west of Rainy Pass.
Once the clearing work begins, the highway is closed to recreationists Monday through Thursday. Friday, Saturday and Sunday you can snowshoe, ski, snowmobile and even bicycle beyond the gates, but we ask you report any vandalism you see when you get back in cell signal range.
North Cascades Highway information
Last year crews started clearing on Monday, April 10, and reopened the highway on Tuesday, May 16. The latest opening was in 1974 when the highway reopened on June 14. During the winter of 1976 to 1977, there wasn’t enough snow to ever close the highway.