With wildfire smoke stretching across Montana, the state has issued an air quality alert for seven counties covered in the polluted haze.

The Montana Department of Environmental Quality issued the alert for Flathead, Lake, Lincoln, Mineral, Missoula, Ravalli and Sanders counties Wednesday morning. The alert is in effect until further notice due to smoke from fires in Canada and western Montana.

An air quality alert means that smoke particulates — which in an excessive amount can be harmful — have been trending upward, bordering on or pushing past national health standards.

“Fires in Montana are causing severe localized impacts near active fires,” according to the alert.

That includes Mineral County along I-90 corridor near the Sunrise fire, in Seeley Lake near the Rice Ridge fire, and near the Gibraltar Ridge fire near Eureka. Smoke from those fires is drifting into nearby valleys at night, causing severe air quality impacts from midnight through midday.

While unhealthy and hazardous conditions spotted Northwest Montana at the time of the warning, Flathead County air quality remained classified as moderate Wednesday morning. That means while people with respiratory or heart disease, the elderly and children should limit prolonged exertion, others can go through their normal routines.

As of 9 a.m. on Wednesday, levels in Seeley Lake were Hazardous, as they had been for days. Other areas like Quartz Creek, Lolo and Superior qualified as “unhealthy.”

Arlee, Eureka, Frenchtown, Hamilton, Libby and Thompson Falls fell in the category of unhealthy for sensitive groups.

When air quality is hazardous, health officials recommend that everyone should avoid outdoor exertion. People with respiratory or heart disease, the elderly, and children should remain indoors.

For more information visit the Montana Department of Environmental Quality at www.todaysair.mt.gov.

Reporter Katheryn Houghton may be reached at 758-4436 or by email at khoughton@dailyinterlake.com.