Helena, Mont. ? Montana, which has served as Marlboro Country in magazine ads depicting rugged cowboys puffing on cigarettes while riding a fence line, is about to outlaw smoking just about everywhere but the great outdoors.

The Montanta Legislature voted Thursday to ban smoking in all enclosed public places, including bars and restaurants.

The Senate approved the measure 40-10 on Thursday. It passed the House last month.

Gov. Brian Schweitzer said he will sign it. Montana will become one of just 10 states to ban smoking on such a widespread scale. California, Connecticut, Delaware, Florida, Idaho, Maine, Massachusetts, New York and Rhode Island have similar laws.

Beginning Oct. 1, the ban will apply to nearly all enclosed places open to the public, including restaurants, stores, office buildings, schools and public transportation. Montana’s 1,700 bars will have until 2009 to comply — a compromise adopted for the benefit of tavern owners.

Over the years, Madison Avenue has used Montana as a backdrop in some of the Marlboro Man cigarette ads.

Lawmakers acknowledged the health dangers of secondhand smoke and instead argued over whether the ban is the kind of heavy-handed government action that riles Montanans, who have long admired the rugged individualism represented by cowboys.

“Smoking is just plain stupid,” said Republican Sen. Joe Balyeat of Bozeman. “But if this Legislature decided to outlaw stupidity, I think two-thirds of us would be behind bars. I just don’t think we can legislate against stupidity.”