ST. REGIS – An overnight landslide has prompted a closure of one of western Montana’s most traveled highways.

Interstate I-90 westbound remains closed as of this morning throughout western Montana to the Idaho border.

“Traffic from I-90 west at milepost 5.5 just past St. Regis is being diverted back onto I-90 east and the highway will be treated as a two-way road with flaggers and pilot cars in place,” said Lori Ryan, spokesperson for Montana Department of Transportation.

Ryan encourages drivers to slow down and use extra caution while driving through this area.

“At this point in time once the roadway is clear MDOT will determine if roads or bridges were damaged from the slide,” Ryan said.

There is no timetable for cleanup or when the interstate will completely reopen nor have injuries or fatalities been reported at this time, she said.