Montana ? A trio of fast-moving new wildfires in Montana threatened more than 100 homes and other buildings, and 80 were under evacuation orders, officials said Monday.

One blaze, discovered Saturday and believed to have been human-caused, had burned about 1,000 acres – about a square mile – along Interstate 90 in western Montana southeast of Missoula. Residents of about 40 homes were asked to leave, according to fire information officials.

Near Philipsburg, residents of another 40 homes were ordered to leave in advance of another new blaze that had burned about 1,000 acres there.

A third fire in the area has been burning for more than two weeks but flared up recently, said Nick Spang, a fire information officer. Granite County authorities were prepared to evacuate as many as 100 homes threatened by the 300-plus-acre wildfire.