The Powell County Sheriff's Office has issued an emergency wildfire evacuation order for all residents in the OS Properties - Garnet Mountain Property area south of Helmville. Residents should leave immediately.
A post on the department's Facebook page says law enforcement and fire personnel are going door to door to assist, but residents should not wait to be contacted.
Montana Red Cross has set up an evacuation shelter at the Assembly of God church in Deer Lodge.
More than 350 personnel are working on The Windy Rock Fire, which has burned 2,000 acres. The lightning-caused fire was discovered 15 miles northeast of Drummond on August 14.