Portion of Idaho 21 To Close Due To Avalanche Warning
Boise County, Idaho ( KMVT-TV / KTWT-TV ) - The 12-mile stretch of Idaho 21 between the Grandjean Junction and Banner Summit will be closed at 4pm this Friday afternoon as an avalanche safety precaution, the Idaho Transportation Department announced. The route will be evaluated regularly for a decision on re-opening when conditions improve.
The first avalanche closure last year was Dec. 16.
Despite 45-50 slides each year and more than 250 inches of snow on average, the forecast team has reduced closures by more than 60 percent since they began forecasting slides and slide threats three years ago.
The notorious "Avalanche Alley" section between the Grandjean Junction turnoff and Banner Summit is home to about 60 avalanche chutes and 90 percent of the Idaho avalanches that affect highways.