SR 20 North Cascades Highway reopens - Massive slides closed the highway to all traffic Sept. 6
The gates opened and the barricades came down on State Route 20 at noon today, Sept. 12, restoring travel over the North Cascades Highway. The highway has been closed since 2 a.m. Friday, Sept. 6, due to mudslides.
Before WSDOT could reopen SR 20, crews repaired pavement and guardrail and completed drainage and ditch-clearing work. Drivers can expect some occasional short delays the next several days while crews continue working on drainage and the slopes on both sides of the highway.
During the six-day closure, a crew of 18 operating 11 trucks, 3 excavators, 3 loaders, a Vactor and a D-8 Caterpillar worked every daylight hour to clear the slides blocking SR 20. Workers and their equipment came from Washington State Department of Transportation maintenance sheds in Newhalem, Coulee City, Electric City, Mansfield, Brewster, Twisp and Stevens Pass. A pair of contract operators from Lloyd Logging in Twisp also joined the crew.
Workers cleared mud, boulders, trees and debris from two sections of SR 20 during the closure. While mud was still flowing on the west side of Rainy Pass Sept. 6, crews were able to clear boulders that blocked lanes below Cutthroat Ridge, about 12 miles to the east. The closure zone then moved from west of Mazama to Rainy Pass, allowing campers and hikers in and out of the many campgrounds and trailheads in that 15-mile section of SR 20.
Clearing from Rainy Pass down to Granite Creek was a much bigger job. Six slides, the largest about 6 feet deep and more than 100 yards wide, came down in the same area where eight slides had closed the highway less than a month ago. This time, the size and number of boulders that came down presented the biggest challenge.
The largest boulder was 10 feet high, 35 feet wide and 25 feet deep. Avalanche control technicians found chemical avalanche charges insufficient and had to drill and use dynamite to break the massive boulder into manageable chunks.
Blasting and other clearing work was interrupted several times each day by bicyclists and hikers who assumed the closure only applied to motor vehicles. Travelers are encouraged to remember that, for their safety and that of WSDOT crewmembers, emergency highway closures apply to everyone.