BLACK HAWK, Colo. -- In just four days, casinos in Colorado must go smoke-free as the extension to Colorado's existing clean indoor air act ends.

In order to comply with the law, casinos in Black Hawk and Central City have spent an estimated $3 to 5 million to accommodate smokers.

"Within the letter and the spirit of the law, we've built smoking patios," said John East, who manages Black Hawk's Lodge Casino.

The Lodge Casino alone has spent $450,000 converting exterior stairways into all-weather patios for smokers, complete with windbreakers and permanent patio heaters.

"Those will allow our guests who enjoy smoking to still enjoy our facility," said East.

Across the street, Ameristar Casino has spent nearly $150,000 converting its patios. "Obviously up here in Colorado we receive a lot of snow as we are today. And we just want to make sure (our smokers) are as comfortable as possible," said Michelle Shriver, senior vice president and general manager of Black Hawk's Ameristar Casino.

The drastic change is drawing mixed opinions from gamers.

"I am a firm believer that smoking can be hazardous to your health," said Shirley Troutman of Denver. Troutman said she visits Black Hawk once or twice a week.

"But I do feel for the people who smoke. Most smokers here are very considerate. They will ask, 'Do you mind if I smoke?' And if they ask, I always tell them I don't mind," said Troutman.

Smoker Ronica Rueb of Greeley just won $4,200 at Ameristar. "I think that this was one of the last places in Colorado where you could come and actually enjoy a cigarette and have a beer and gamble and enjoy yourself. And now, they're going to take that away too," said Rueb.

"I might as well spend $118 on a roundtrip ticket to Vegas, where you can smoke," added Rueb.

Most managers believe the ban will initially put a ding in business. "We expect there will be some bumps early on," said East.

"History has shown that it's anywhere from a 14 percent decrease in revenue to a 30 percent decrease in revenue in other jurisdictions," said Shriver. "It remains to be seen what the ultimate impact will be, but we are absolutely expecting some financial impact to the property," said Shriver.

"Hopefully those hits are going to be short term," said East.