Update: More of Idaho Highway 21 to close near Idaho City because of avalanche concerns
Idaho drivers need to rethink travel plans northeast of Boise because of avalanche closures.
The Idaho Transportation Department said late Monday morning that Idaho Highway 21 between Grandjean and Banner Summit would close at 5 p.m. The department then announced a second closure of 31 miles between milepost 41 in Idaho City and milepost 72 in Lowman.
Avalanche experts were concerned that weather conditions were “likely to trigger avalanches in this section of highway,” the department said.
The transportation department said it had no estimated time to reopen the road, and would wait until “the snowpack has stabilized and the risk of active avalanches is reduced.”
It advised drivers to take alternate routes, such as Idaho Highway 75, if needing to travel from the Boise area to places such as Stanley.
Spokesperson John Tomlinson told the Idaho Statesman that the situation was “changing and evolving quickly,” adding that more closures could be announced.
The 11-mile section of Idaho 21 being closed includes nearly 70 areas where avalanches can occur, according to ITD.
“Avalanches can be triggered without warning, so there is no parking or stopping within this section of road during the winter,” the department said in a news release.
Tomlinson said ITD’s experts looked at snowpack, moisture, the potential for rain or snow, weather patterns and current temperatures when making the decision.
A winter storm warning is in effect for that part of Idaho until 5 p.m. Friday, according to the National Weather Service.
“They have stations that they’re monitoring all along there,” Tomlinson told the Statesman by phone. “And then based on their expertise and the data, they factor all that in when deciding whether to close it or not.”
Earlier this month, a Kuna man became the first man to die in an avalanche in the United States this winter when he was buried in snow while snow biking near Cascade.
This story was originally published December 26, 2024 at 1:14 PM.
