Crews to start clearing SR 20 North Cascades Highway in March

WENATCHEE – WSDOT crews found lower-than-normal snow levels during a recent field trip up the North Cascades Highway to assess snow conditions. Based on the findings, crews now plan to start the annual snow-clearing effort to reopen the highway on March 22.

The assessment team and observers arrived at the Silver Star gate eight miles east of 5,477-foot Washington Pass about 8 a.m. on Feb. 22. It was 14 degrees with beautiful, clear skies, but nothing approaching “normal” snow conditions. 

In the words of avalanche control supervisor Mike Stanford, “Right now, snow and debris amounts are down compared to previous years. We dug a snow pit near the summit and found a relatively shallow and stable snow pack.”

Surprisingly, crews also found huge hoarfrost crystals – as big as playing cards (up to 3.5 inches). Pictures of the crystals and the assessment trip are on posted on Flickr: www.flickr.com/photos/wsdot/sets/72157623371473447/.

“The crystals could pose a safety problem for us when we return in March, depending on how much new snow we get in the next month,” Stanford said. “New snow on top of the crystals would turn the frost into a “slip plane,” increasing the avalanche danger.”

If there is no significant new snow fall between now and the spring opening, most of the avalanche zones should melt back without dumping any more snow or debris on the road.

Despite the lower-than-normal snow totals, the March 22 start date isn’t any earlier than the previous four years’ start dates.

“We really can’t start any earlier,” maintenance assistant region administrator Dave Bierschbach said. “Our mountain pass maintenance crews and equipment are on an round-the-clock winter schedule until Mar. 15.  That’s the soonest we can release any of the snowblowers and crews from the other mountain passes and bring them here.” 

Bierschbach also said that the lower-than-normal snow amounts should make for a faster-than-usual opening and that it could take as few as three weeks instead of the usual six.

The assessment team took snow-depth measurements from Silver Star Gate (milepost 171) all the way to the bare pavement they found about nine miles above the west side closure gate (milepost 134).

• ·         Silver Star Gate - 3.3 feet compared with 2 feet last year.
• ·         Cutthroat Ridge #6 - 9 feet compared with 25 feet last year.
• ·         Liberty Bell Mtn. #1 – 12 feet compared to 40 feet last year.
• ·         Washington Pass – 6 feet compared to 5.5 feet last year.
• ·         Rainy Pass – 3.3 feet compared to 6 feet last year.

Crews on the west side of 4,855-foot Rainy Pass have already been at work shaping ditches and cleaning culverts above the closure gate where snow has already melted.

The highway was closed for the season on Nov. 17, 2009. Last spring, the highway reopened on Apr.24. 

For more information, visit the SR 20 North Cascades Highway web page:
 www.wsdot.wa.gov/Traffic/Passes/NorthCascades/

 Contact: Jeff Adamson, North Central Region Communications Manager, Wenatchee, (509) 667-2815, (509) 669-8778 Cell. E-mail: adamsoj@wsdot.wa.gov

printer friendly