The smoke hanging around does more than obstruct a view of the mountains.
It's unhealthy too.
The Missoula Health Department reports air quality in Missoula and the Bitterroot, is unhealthy enough to limit exposure for sensitive people.
The air looks almost like you could weigh it on a scale.
Seniors, children, smokers, anybody with lung problems, are advised to limit physical exertion and their time outdoors.
But it's really not healthy for anybody.
"Your general run of the mill person might not be all that sensitive ," said air quality specialist, Sarah Coefield, " but should still be kind of conscious of their response to smoke and try to limit some of their long term exertion outdoors."
Much of the smoke is drifting from the west, mostly from fires in Idaho,
The smoke is expected to stick around through Wednesday.