A series of four avalanches that began Thursday evening forced closure of the U.S. 12 east of Lowell and left a dozen semi-trucks/trailers stranded.
The first avalanche, about 20 feet high and 50 feet across swept onto U.S. 12 at about 4:45 p.m. (MST) Thursday. Initially, two semi-trucks were stranded on both sides of the avalanche because they were unable to turn around on the two-lane highway that follows the Lochsa River. Eight others arrived at the scene before the highway was closed.
Occupants of all 12 trucks remained at the site overnight and were transported by ITD personnel to maintenance facilities and then to Kooskia, which is about 73 miles east of Lewiston. There were no reported injuries; no medical units were dispatched and no medical services rendered.
One of the three subsequent avalanches pushed a loaded lumber truck into the Lochsa River. It was not occupied and remains in the river.
The second avalanche is about 10 feet high and 100 feet across; the third is about five feet high and 50 feet across and the fourth is about 20 feet high and 100 feet across.
ITD crews were in the process of closing the highway Thursday afternoon when the first avalanche occurred. The transportation department maintenance facility at Bald Mountain, about eight miles west of the avalanche area, received two feet of new snow Thursday. About four feet of snow has accumulated at the facility.
An avalanche mitigation expert under contract to ITD is en route to the U.S. 12 closure today. He will assess the avalanche risks and advise ITD on how to proceed.
The highway remains closed indefinitely between milepost 99 (Lowell) and milepost 174 (Lolo Pass). ITD officials in Lewiston said the highway could remain closed for a week.
snow in the region makes slopes along the highway extremely unstable
and removal of the avalanches very difficult.
Snowstorms and steady winds continue to make travel difficult in most regions of Idaho.
Motorists are advised to use the 511 Traveler Services Web site (511.idaho.gov) or dial 5-1-1 for the most current highway conditions in Idaho. The Web site and telephone system are updated as conditions change.