HELENA, Mont. — Residents of Seeley Lake are threatened by air that Montana environmental officials have classified as hazardous because of fires burning to the east and west of the town.

The Department of Environmental Quality warned Tuesday that all adults and children in the area should avoid going outside or limit their outdoor activities.

Much of the rest of southwestern Montana is also feeling the effects of wildfire smoke. Residents of Butte and Hamilton are being warned that the air quality is unhealthy for sensitive groups, such as children and people with respiratory disease.

The Northern Rockies Coordination Center says there are 20 large fires burning in Montana. Nine of them are concentrated in a triangle between Philipsburg, Superior and Seeley Lake in western Montana.