Update: Idaho Highway 21 remains closed west of Stanley due to avalanche danger
A stretch of Idaho Highway 21 between Lowman and Stanley remained closed to traffic Friday in both directions because of avalanche danger, according to the Idaho Transportation Department.
Between Grandjean and Banner Summit — a stretch between 23 and 35 miles west and south of Stanley — the road has been closed since shortly after 5 p.m. on Thursday, according to the ITD website.
After assessing the road conditions Friday morning, ITD announced the road would remain closed and be reassessed at 5 p.m. Friday.
The highway connects southbound travelers leaving Stanley with Boise County and the Treasure Valley, and the affected stretch is sometimes called Avalanche Alley. There are 60 avalanche paths along the 11-mile span of highway near the Sawtooth Mountains, according to a Thursday ITD news release.
“Avalanches can be triggered without warning,” the release said. “For this reason, there is no parking or stopping within this section of road during the winter.”
As an alternate route, drivers traveling between the Treasure Valley and Stanley can take Interstate 84 south to Mountain Home, U.S. 20 east and Idaho 75 north through the Wood River Valley.
On Thursday morning, the National Weather Service’s Boise office forecast lots of snow in the mountains of Central Idaho between Thursday morning and Saturday afternoon. The office predicted 6-10 inches of snow in Lowman and between 14 and 18 inches in Stanley, according to a tweet. Snow is in the forecast in both areas through at least Monday.
In March 2019, the same stretch of highway closed after an avalanche buried it under 40 feet of snow.
This story was originally published December 23, 2021 at 8:14 PM.
