ARDEN HILLS, Minn. —On a recent balmy midsummer day, Shawn Ryan spent his lunch break downhill skiing in a warehouse in Arden Hills. “You tell people in your office you're skiing on an 85-degree day,” said Ryan, who works for 3M.

Ryan's ski season never has to end thanks to the Alpine Factory. The business consists of two massive downhill treadmills where skiers and snowboarders can carve turns on an endlessly rotating carpet of artificial snow in a climate-controlled environment.

The ski-hill-in-a-box is the creation of Jessica and Dan Parcheta, husband and wife ski instructors from Stillwater. They were introduced to the concept of an “infinite revolving slope” on trips to Austria and Argentina, where they met ski instructors from Holland.

Holland, as you probably know, is a flat country where the highest hill is only about 1,000 feet above sea level. But about 20 years ago, ski-loving Dutchmen created a way to simulate skiing on a big, tilted treadmill featuring a rotating belt of slick “ski grass” or “ski carpet,” a synthetic mat similar to AstroTurf.

“We were skeptical about it at first,” said Dan.

But the Parchetas, who have Level III certification with the Professional Ski Instructors of America, tried the treadmills in Holland about two years ago.

“After you ski on it for a while, it's like, 'Yes, this is really skiing,'” Dan said.

The couple decided to import two of the treadmills and start a business catering to skiers who want to improve their skills or keep in shape during the offseason. They discovered that it also attracted people who've never skied and wanted to learn in a controlled environment.

Colorado, Florida and California have treadmill skiing centers, but the Alpine Factory, which opened in January, is the first of its kind in the Midwest, according to Dan.

Each treadmill has a skiable surface of about 20 by 40 feet and can accommodate three skiers at a time.

Instructors can adjust the pitch and speed of the treadmill, simulating conditions ranging from bunny hill to black diamond, according to Jessica. Instructors can use a remote control to stop the machine if someone falls or starts to lose balance.

Hourlong sessions on the machine cost $44 for a group lesson or $79 for a private lesson, with discounts for packages and membership options. Coaching and ski equipment rental is included with each session.

Typically, skiers will ski 10 minutes at a time followed by a 10-minute break. While that may sound like a short run, 10 minutes is a lot longer than it would take to go down any slope in this area. In fact, in as little as 30 minutes on the alpine treadmill, a skier could clock the equivalent number of turns and minutes sliding downhill in a whole day at a ski resort, where much of the time is spent waiting and riding on ski lifts.

Experienced skiers who have tried the treadmill say the artificial surface has the somewhat grippier resistance of very warm or very cold snow.

But “it's skiing,” said customer Doug Danks, a 53-year-old architect from Birchwood Village. “All the sensations are very, very familiar,” he said. “It's an amazing workout.”

“In 10 minutes I was sold,” said Ron Clarkson, a 70-year-old ski instructor from Woodbury who is using the treadmill to improve his skills to reach a higher instructor certification level.

It's not the only summertime downhill skiing option around.

Last fall Buck Hill installed a “dry ski slope” on some of its hills.

This summer, the Burnsville ski area has three runs available for skiers and snowboarders who can slide downhill on a synthetic matting made by an Italian company called Neveplast. The longest artificial ski run at Buck Hill is 1,000 feet long and 60 feet wide and is served by a chairlift. There are also three tubing runs operating this summer using the synthetic surface.

David Solner, one of the owners of Buck Hill, said installing the artificial ski surface is part of an effort to make downhill skiing a year-round activity no matter what happens with the climate.

“It's been a little challenging from a cultural standpoint to understand you can go skiing in the summertime,” Solner said.

But he said he thinks the idea will catch on as the weather cools and skiers start thinking about getting a jump on the regular ski season.

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Treadmill skiers say the device is particularly helpful for improving skills.

Sliding on the machine, Clarkson said he is able to get a continuous real-time critique from Jessica Parcheta, who provides feedback while standing a few feet away at the bottom of the treadmill.

In a typical ski lesson on real snow, you have to wait until everyone gets to the bottom of the hill before the instructor tells you what you did wrong.

Another instructional aid you'll never see on a mountain: There's a big mirror at the bottom of the treadmill where you can watch your technique as you ski.

“I think it's amazing for teaching,” said Dan.

And there's no need for goggles, ski jackets or mittens. The 5,000-square-foot warehouse is kept at shirt-sleeve temperature.