Montana - The Montana Clean Indoor Air Act

Statewide smoking ban: On October 1, 2005, the Montana Clean Indoor Air Act (MCIAA) went into effect, banning smoking statewide in all enclosed including workplaces in Montana including restaurants, though bars were exempt until October 1, 2009; the word "bar" is defined in the Act as also including taverns, night clubs, cocktail lounges, and casinos.

The act exempts private residences not used as a daycare facility or healthcare facility, private motor vehicles, tobacco demonstrations in schools, designated hotel/motel smoking rooms, and Native American religious and cultural activities. Local governments are preempted from regulating smoking more stringently than the Act.