“Avalanche Alley” will close at 6:00 p.m. Friday as a safety precaution. That’s the 12-mile stretch of Idaho 21 between Grandjean Junction and Banner Summit.
The Idaho Transportation Department (ITD) reports the area received eight inches of snow Friday morning and more snowfall is expected Friday night and Saturday.
The area averages more than 250 inches of snow which brings 45-50 slides each year. About 90 percent of avalanches that affect Idaho highways happen on "Avalanche Alley."
Friday night's closure will be the second this year. The road closed down for three days in January when nine slides were reported.
Since avalanches were "imminent" during that closure, ITD decided conditions were right to break out its Avalauncher. Spokesman Reed Hollinshead says the device shoots explosives onto a hillside to bring down the snow without endangering the public.
“Rather than wait for the final push from Mother Nature," says Hollinshead, "we’ll often take that step ourselves, so we can open that back up because we are very aware that the Lowman area is dependent on that road being open.”
Hollinshead says crews will re-assess Idaho 21 Saturday morning to see if the road can re-open. But he warns with more snow on the way, the closure could drag into Monday or Tuesday.
Copyright 2014 Boise State Public Radio
