BUTTE, Mont. -

Hit hardest Thursday, areas like the Flathead Valley, Frenchtown and Butte, where air quality is considered unhealthy for sensitive groups.

Working with children for more than a decade, Missy Okrusch knows she has to make sure it's safe outside for her kids and this time of year that means checking the air quality website daily.

On Thursday, her preschool kids were playing outside, but she made sure to watch the kids closely.

That's because young children are considered one of several groups sensitive to smoke, like the elderly and chronically ill.

Prolonged exposure could lead respiratory symptoms, like difficulty breathing.

"If we have kids that have asthma then they'll stay in even if it's on good  and a little bit smoky," said Okrusch.

That is exactly what air quality specialist Paul Riley recommends on days like this.

"It's really not that significant yet, unless you do have asthmatic conditions," said Riley.

Riley checks his air quality monitoring station several times a day and uses landmarks to gauge just how bad conditions are.

Riley said he looks to the East Ridge as a gage of how poor the air quality is.

"The more difficult time we have seeing that, the more particulates are actually in the air," said Riley.

And he's not the only ones looking to the mountains, Okrusch said she'll gauge how safe it for her preschool kids by checking Highland Mountains or East Ridge.

"If you can't see the mountains generally its a good thing you don't go outside," she said.