Gusty winds and low humidity helped the fire on Lemhi Pass grow to more than 6 square miles on Wednesday.
A late night infrared flight over the Bear Creek fire on Wednesday mapped its size at 3,987 acres, fire officials said in an update Thursday morning.
The lightning-caused fire along the Montana-Idaho border has kicked up smoke that can be seen from around the region, including in Bozeman. It was first discovered on Tuesday. On Wednesday, firefighters used burnouts and other work to clear fuels ahead of the fire. They were also able to stem movement on the fire’s eastern flank and worked with ranchers to move livestock out of the area, according to Thursday’s update.
More “critical” fire weather is expected Thursday. Officials expect high winds to push the blaze in some spots. They also expect to see short crown runs and some spotting.