Firefighters are responding to a new fire reported at 1:11 p.m. south of Darby.
The Deer Hollow Fire is estimated at 50 acres and ignited in private lands, threatening structures in the Rye Creek area, according to the Ravalli County Office of Emergency Management.
Darby Rural Fire Department responded along with mutual aid resources from US Forest Service and Sula, Hamilton, Corvallis, Victor, Pinesdale, and Stevensville Rural Fire Districts.
Air attack, helicopters and large air tankers have also been called, according to fire officials.
Officials warned that fuels in the valley floor have dried out quickly and can easily ignite.
This is a developing story. Check back for details.