2/24/2014
Reed Hollinshead
ITD Communication
208-334-8881
reed.hollinshead@itd.idaho.gov
Avalanche Alley section of Idaho 21 to close at noon for slide threat
BOISE COUNTY - The 12-mile stretch of Idaho 21 between the Grandjean Junction and Banner Summit will close today (Monday, Feb. 24) at noon as an avalanche safety precaution. Warming temperatures in the area will bring rapid melting and instability to the existing snowpack, which has been supplemented by at least 29 inches of new snow during the last five days.
During the two previous closures this year, the area experienced
a total of 60 slides, 30 of which reached the highway. In the latest closure, about a week ago, nine of the 25 slides reached the
roadway; two of the avalanches were large – 40 feet deep and several
hundred feet wide each. Tons of timber and debris also reached the
highway.
The notorious "Avalanche Alley"
section between the Grandjean Junction turnoff and Banner Summit is home
to approximately 60 avalanche chutes and 90 percent of the avalanches in the
state that affect highways.
For the latest highway and weather conditions, call Idaho Traveler Services at 5-1-1. For online updates, visit the website at 511.idaho.gov. Telephone and Web reports are available 24 hours a day and are updated as conditions change.