Signs of the big change at Mountaineer Casino are difficult to miss. Smokers perch on benches outside the main entrance, indulging their habit. A sign on the door declares the casino in Chester, W.Va., about an hour outside Pittsburgh, a "smoke free facility." Near the main floor, another sign reminds everyone that this is a "smoke free area." A few yards away, a placard points the way to the smoking pavilion.

Mountaineer, forced to ban smoking throughout the main floor on July 1 when a tougher Hancock County clean-air ordinance took effect, now boasts that it offers the "best of both worlds." Smoking is forbidden throughout the main floor, which has 44 table games and about 1,440 slot machines. The $2 million smoking pavilion, billed as the country's largest outdoor gambling facility of its kind, has six table games and about 200 slots.

Several gamblers there on the 46^th annual West Virginia Derby Day, which featured a horse race boasting a $750,000 purse, applauded the change; some in the pavilion thought it stunk.

In the first 12 weeks of the smoking ban, gaming revenue dropped by about 25 percent from the previous year. From July 1 through Sept. 19, slot and table game revenue totaled $30.15 million, down from $40.32 million in the comparable period for 2014. The 2014 total includes an extra day’s worth of revenue, but the drop is substantial.

Mountaineer is not alone in experiencing a drop in revenue immediately after a smoking ban takes effect. In New Orleans, a citywide smoking ban took effect April 22; from May through August, Harrah’s New Orleans has seen revenue drop by almost 10 percent.

Mountaineer General Manager Chris Kern told me the smoking ban is only part of the reason for the decline at his casino. Mahoning Valley racetrack in Youngstown, Ohio, added slot machines in September 2014, and Mountaineer revenue had fallen since.

"Our initial impact was much less than other jurisdictions have experienced when they went nonsmoking," Kern says. Smokers appreciate that Mountaineer opened a large pavilion with a variety of options in slot denominations and machine types, he adds, "Players thoroughly enjoy it out there," he says. "It’s almost like a different casino. It’s a different feel, a different vibe from the rest of the building."

The pavilion, designed to meet the Health Board’s definition for an outdoor area, features a permanent roof with several heaters as well as large fans to keep the air moving. Kern said the casino built new walls five feet outside the roof line, and those are technically not part of the building.

Despite the "outdoor" designation, the pavilion appears to be just another room in the casino. Players can enter from the parking area or through glass doors that separate it from the main casino.

The smell of tobacco smoke hits immediately. Gary Booth of New Waterford, Ohio, whose wife and daughter smoke but not in the house or his car, endorsed the ban. He noted that the main floor was crowded on Derby Day and the smoking pavilion was jammed as well. He thinks more nonsmokers will visit Mountaineer as word spreads.

John and Margaret Fites of Suffield, Ohio, didn’t know about the smoking ban when they drove about an hour to Mountaineer. "I’m used to it," Margaret said as she and John demurely smoked on a bench outside the casino. "It doesn’t bother me." They hadn’t been to Mountaineer in about 20 years and decided to drive down on Derby Day. Ohio casinos are all non-smoking.

Cindi Drabik of Brunswick, Ohio, playing a Red Empress penny slot in the smoking pavilion with husband George, gave a terse review of the no-smoking policy: "It sucks." They live near Cleveland and drive 90 minutes or more to get to Mountaineer. Her favorite machines aren’t in the pavilion, and the smoking area is packed, she says. "I’d just have more fun if I was out there," she adds.

On the main floor, open blackjack seats were hard to find on Derby Day. My wife and I wound up playing at a $15-$300 eight-deck shoe with S17 and about 70 percent penetration.

The ban allows Tom Clemens of Steubenville, Ohio, to play blackjack more often and on any day he gets the urge. "Going nonsmoking did a lot of good for everyone," said Clemens, who uses an oxygen tank to breathe because of damaged bronchial tubes. "People are starting to come back." He said the smoke didn’t bother him that much before the ban, but he had to limit his Mountaineer trips to days the casino was less busy. If a rude smoker sat down and wouldn’t stop blowing smoke his way, he’d half-jokingly threaten to smack him with the oxygen tank. "Now I can go on Friday and Saturday," Clemens said.