A wildfire that started near Interstate 90 about two miles northwest of Superior had grown to an estimated 700 acres by Monday afternoon.

Mandatory evacuations are in place for the Flat Creek and Pardee Creek areas, involving 30 homes, according to an afternoon update on the West Mullan Fire.

Forest Service and local rural fire departments are providing structure protection.

Firefighters on Monday began burnout operations on the southwest side of the fire to eliminate fuel and provide a buffer zone for nearby structures.

Fire crews also are trying to keep the fire from moving east toward homes.

Two crews are fighting the fire with a dozen engines plus three helicopters dropping water. Lolo National Forest spokesman Boyd Hartwig said fire managers have requested three more helicopters and two 20-member hotshot crews.

Fire managers expect the activity of the fire to be weather- dependent: Any increased temperatures, low humidity and/or windy conditions would increase fire activity.

The West Mullan Fire started at about 5 p.m. Sunday and had burned about 150 acres by 8:30 p.m. and 500 acres by Monday morning. 

The cause of the fire is under investigation.

Fire management officers were to brief the public about the fire Monday at 8 p.m. at a public gathering on the lawn of the Mineral County Courthouse in Superior.

Keith Cousins of the Mineral Independent contributed to this story.