We’re in the peak of tourist season in Montana, and it's the busiest time of the year for airports across the state. Before you pack your bags, you need to know about these banned items. Get our free mobile appHere are the Most Common Prohibited Items at Montana AirportsBear Spray: Banned in carry-ons and checked luggage on commercial flights due to discharge risks. Below, you can find a quick guide to items that are banned at airports in Big Sky Country. 17 Items That Are Banned From Checked Baggage at Montana Airports Flying out of a Montana airport?