Pass clearing continues on North Cascades Highway

By Jeff Adamson

They’re back…Pink Floyd and his family of avalanche safety flamingos. Yes, they ARE cute, but they have an important duty.

Pink Floyd pointing out
work zone hazards.

The flamingos are eye-catching tools that point out hazardous zones to the snow removal teams. They’re reminders to always have your “avalanche eyes” open for chutes, debris, another work crew and other hazards. Now if we could only agree on which song to go with our mascot...

East side update

On Monday, April 7, Pink Floyd joined the east side snow removal effort on SR 20 – North Cascades Highway as the team’s avalanche training refresher at Silver Star Gate kicked off the second week of this massive snow removal project . Then it was off to begin clearing just above Lone Fir Campground.

While the maintenance crew pushed and blew snow from SR 20, the avalanche team climbed to the 6,200-foot-level up Liberty Bell Mountain.
Snow blower at Lone Fir Campground.

Spring’s rising temperatures can trigger snow slides below – a major hazard for crews. The avalanche control team dug a snow pit and assessed the Liberty Bell Mountain zone to determine which layers of snow might separate and slide. It tells them what the avalanche potential is and what kind of snow movement to look for when the maintenance crew progresses into the giant Liberty Bell avalanche zone.

In years past, the avalanche control team doesn't join the clearing effort until the east side maintenance crew reaches Cutthroat Ridge in the second or third week. The zone has 12 active chutes.  This year, the avalanche team has been on site monitoring unstable slopes since week one. Most of the winter’s snowfall didn't start falling until mid-February so what’s on the slopes isn't as stable as snow that’s spent all winter compacting on itself.

A second bulldozer joined the east side clearing effort.
Last week, the two teams joined to take on Cutthroat Ridge and by week’s end, they had cleared through Cutthroat Ridge avalanche chute 8 at milepost 164.5.  Think of a layer cake. A snow blower can handle six-feet or so of snow no problem. In an avalanche zone, a snow slide can be 10 times that height and as wide as a football field.

The solution is to cut the top layer off (anything over 6 or 8 feet) and the tool of choice is a bulldozer or two. Through the Cutthroat zone, a D-6 caterpillar worked the top of the slide and when its work was done, the maintenance crew’s excavator, snow blower and a grader cleared the snow down to the pavement.
When they get to the end of the Cutthroat zone, a larger D-8 cat we lease from a local logging company joins the effort to cut down the top layer of the more than 30-foot-deep slides in the Liberty Bell Mountain zone.

West side update

Eastbound SR 20 clearing continued on Monday, April 7, just beyond the Canyon Creek Trail.
Snow blower on SR 20
just below Easy Pass.

By the end of week two, the two-man team had eastbound lanes cleared and widened to about three miles short of Swamp Creek. The less-than-a-foot snow depth increased to 4 feet as they worked towards Rainy Pass. Next, the team will be moving forward towards Easy Pass.

Here are some short answers to questions you might have:
  • The closure gates stay closed until the entire highway is reopened (estimated about the second week in May)
  • No licensed motor vehicles are allowed beyond the gates, but boots, bikes and snow mobiles are.
  • We work Monday through Thursday, leaving Friday through Sunday for uncontested(!) recreation, but we encourage you to check the back country avalanche forecasts and weather before you go  
  • We also ask you to stay clear of our clearing equipment so no one gets hurt or hurts it

Check out photos from the SR 20 North Cascades Highway snow removal project on Flickr.