MAZAMA - After a Snow Cat trip over the snow-covered North Cascades Highway Feb. 23, state Department of Transportation avalanche and maintenance technicians say the annual snow-clearing work could start in late March or early April.
     Crews discovered more avalanches than normal and in places they’ve never seen before.
     DOT crews started from the east closure point on state Highway 20 west of Mazama and traveled 20 miles to Rainy Pass, assessing snow and avalanche conditions to determine when the snow clearing could begin.
      “We expect to be able to free up the personnel and equipment we need for the reopening from Stevens Pass and other facilities by late March or early April,” said Okanogan Maintenance Superintendent Dean Hills.
     “Of course, weather, crew health and equipment availability or breakdowns can always change the plan,” he said.
     Those on the survey trip encountered overcast skies, 27-degree temperatures and a trace of new snow. Only four-one hundredths of an inch of precipitation had fallen in the previous 24 hours and most of that was rain.
     Avalanche Control Technician Mike Stanford said they found only moderate snow depths.
     “The flat snow at Washington Pass summit is only five and a half feet deep," he said, adding that seven to nine feet is more typical.
     "The avalanche cycle we encountered in December left some interesting debris on the road. Some of slides look like lava,” he said. “More snow and slides could affect how long the reopening will take. It depends on the weather we get this spring - cool and clear or warm and wet.”
     The largest slides are below Liberty Bell Mountain, just east of Washington Pass. The highway passes under the avalanche zone, and then loops back to the east around what’s called Spiral Gulch.
     “The snow is 20 feet deep and stretches 1,200 feet across the pavement below Liberty Bell chutes No. 2 and No. 3, across the gulch in an area called the Annex.” said Stanford. “The main Liberty Bell avalanche chutes are 40 feet to 50 feet deep over the roadway, which is normal for this time of year.”
     To the east, slides in the Cutthroat Ridge zone are as much as 20 feet deep and 1,200-1,500 feet wide, he said.
     Another anomaly is a 20-foot deep slide near Bridge Creek, between Rainy and Washington passes.
     “I haven’t seen debris on the road here in 18 years,” said Stanford.
     The highway was closed for the season Dec. 11. Last spring, the highway reopened May 1. Photos from the assessment trip are at www.flickr.com/photos/wsdot/sets/72157614387037548/. More information is at www.wsdot.wa.gov/Traffic/Passes/NorthCascades/.