As for Montana there is alot of activity.
Delta flies into Billings,Bozeman, Butte, Helena, Missoula and Kalispell
Northwest flies into Billings Bozeman and Kalispell
United into Billings Missoula and Kalispell
Big Sky files all over the state
Horizon Air, Billings, Helena and Kalispell
So there is quite a bit of Activity in Montana, Wyoming is a diffrent story, not as much traffic.