Update: All Idaho 21 lanes back open after winter storm and ‘major avalanche danger’ pass
A section of state highway north of Boise reopened after experts deemed the “major avalanche danger” had passed, the Idaho Transportation Department said.
The transportation department announced that all lanes of a 12-mile stretch of Idaho 21 between Grandjean and Banner Summit was closed to traffic starting Saturday. The Sawtooth Avalanche Center said avalanche conditions in that area became “downright scary” this week as a “powerful storm” moved through the area.
Officials reopened the roadway at 8:45 a.m. Thursday, according to department spokesperson Megan Jahns.
“Our avalanche team looks at a variety of factors, such as the condition of the snowpack and the forecast, when determining when to close and when to reopen the highway,” Jahns told the Idaho Statesman by email. “With this storm past and the cleanup complete, it was time to safely reopen it for traffic.”
The closure previously extended from milepost 93.7 to 105.5, near the boundary line between Boise and Custer counties.
This story was originally published March 16, 2025 at 1:02 PM.
