While many ski resorts have embraced bikes as part of their business models in the summer months, many find themselves suddenly coping with them in the winter as well.

Fat bikes started as one-off custom Frankenbikes built to tackle snow-covered terrain in ultra-sport races, such as the 1,000-mile Iditarod Trail Invitational. But today they are mass-produced and have become an increasingly popular vehicle for winter (and even summer) recreation.

The high-volume, low-pressure tires on fat bikes allow cyclists to get out and ride more than ever during the winter months, thanks to the traction they provide on soft surfaces such as snow. But as they become more mainstream, fat bikes are sharing snow-packed trails with user groups such as Nordic skiers and snowshoers—and in at least one case, with downhill skiers and snowboarders.

Fat bikes have been commercially available for roughly a decade. Since the popularity of these big-tire bikes shows no signs of slowing, ski resorts across North America are working to adapt guidelines, terrain and events to not only address user conflicts and trail access, but support the growth of the sport and explore its potential for new user visits and revenue.

Taking Off in Targhee

In 2012, Grand Targhee Resort became the first North American resort on record to officially welcome fat bikes to its Nordic trail system. “It’s definitely part of our recreation plan for the wintertime,” says Ken Rider, Targhee’s marketing director.

The resort, perched high in the Tetons on the Wyoming-Idaho border, has been making significant investments in its downhill mountain bike park and cross-country trails during the summer months. It sees the rising popularity of fat bikes as a way to bridge the seasons. “The bike park never closes,” says Rider.

He says it began when some staff members, including head trail builder Andy Williams, started showing up to work on fat bikes and using them to get around during the winter. They were already popular with locals on trails around the valley. The resort soon made the decision to officially allow riders to access its 15k Nordic trail system, Bob’s Basin, which caters to cross-country mountain bikers in the summer as well.

“It’s definitely become more of a multi-sport trail system,” says Rider. There were a few disgruntled skeptics among other user groups when fat tires first hit the snow, he says, but overcoming that was just a matter of education—a lot of which was accomplished via prominent new signage encouraging courtesy on the now multi-user trail.

The number of fat bikes at the resort grew so quickly that in 2014, Grand Targhee opened a 4.5-mile groomed fat bike-specific singletrack called Jolly Green Giant. Like Bob’s, this trail is also open to cross-country bikes in summer.

The labor needed to build and maintain fat-bike trails is currently divided among existing staff. But many of these trails may need dedicated personnel as fat bike use continues to grow. Rider is adamant that it’s a worthwhile all-season investment, more than offset by the substantial increase in Nordic ticket sales during the winter, as riders need tickets to access both Bob’s and Jolly Green.

It’s not only core cyclists who are coming to use the trails, he says. Targhee’s winter visitors will often rent a bike from Habitat—the resort-owned bike shop that now stays open year-round—to take a break from skiing and try something different, or when snow conditions aren’t the best.

“Being able to add additional amenities and things for people to do only increases our visibility as a year-round destination,” says Rider.

Taking on The Worlds

Targhee isn’t alone. Crested Butte Mountain Resort, a Colorado hub for year-round outdoor recreation, recently added fat bikes to its uphill use policy. This allows fat bike riders—as well as Nordic skiers—access to the mountain’s terrain before and after normal lift operating hours.

“The Fat Bike World Championships forced us to pay attention,” says Erica Mueller, Crested Butte director of innovations and relations.

The Fat Bike World Championships is a five-day festival of riding and racing that celebrates the corpulent casings. It made its debut last winter, attracting hundreds to the town of Crested Butte. Spearheaded by Crested Butte Chamber of Commerce director Dave Ochs, the event put the town—and the resort—on the fat bike map.

Following several days of racing, the grand finale was held on the resort’s slopes. “The Hair of the Dawg” sent fat-bike riders down two snow-packed downhill runs, with berms, rollers and jumps that are normally part of CBMR’s Evolution Bike Park in the summer months.

“It was exciting for us, but it raised the question: Where are we going as a resort?” recalls Mueller.

At the time, fat bikes were not officially allowed on the resort’s alpine terrain. Shortly after the Worlds, though, the new policy was in place, nearly identical to that governing uphill skiing. Uphill users are required to purchase a $10 day ticket that excludes lift access.

“The summer bike business is building. And continuing on that track, I think the more we can offer guests an experience as more of a ‘mountain resort’ and not just a ‘ski resort,’ the more attractive it is,” says Mueller. “The more things people can do and experience the mountain, the more they’re going to want to come back.”

And like mountain biking in the summer, the fat-biking presence extends far beyond the resort. Fat-bike riders can also purchase a pass to access the North Village Loop, a 5k portion of the town’s 50k Nordic Center. Fat bikes can be seen rolling through town on daily commutes as well as heading out on all-day adventures.

Testing its Traction

The Carrabassett Valley in western Maine, home to Sugarloaf Mountain Resort, has seen a similar rise in the popularity of the sport. Fat bikes frequent the Narrow Gauge Pathway, a 6.6-mile multi-use trail, and the nearby Hudson Valley trail network.

But Sugarloaf is still evaluating how these bikes fit into its winter operations. “That’s something that we’ve been talking about, how we can increase our fat-bike offerings in the future—whether that’s through specific hours, trails, or terrain,” says Ethan Austin, Sugarloaf’s marketing manager.

“The guidelines would definitely fall in line with the uphill and Nordic traffic; it’s just a matter of figuring out how it will co-exist with what we’re currently doing. The speeds are different, the way the trails need to be groomed are different. It’s a matter of finding out what fat-bike enthusiasts want and what makes a good experience for them, and how we might be able to provide that while still providing everything we currently do for our Nordic guests,” says Austin.

Although the resort is approaching the issue cautiously, it has welcomed fat-bike riders to its Fat Tire Festival for two years now. The three-day event includes bike demos, retail vendor booths, and guided rides throughout the Valley. Sugarloaf also hosts a race on its alpine terrain, similar to a cross-country mountain bike format. Riders race up a groomed run before bombing down a snowboarder-X course that is slightly modified for the bikes. There’s also a dual-slalom race down a ski run.

“It allows fat-bike enthusiasts an opportunity to interact with each other and utilize some of the terrain up here that they might not be able to utilize otherwise,” says Austin. “It’s very popular here, and it’s only growing.”

Going Downhill

While lumping fat bike riders in with uphill and Nordic users seems to be the default approach, one Midwest ski area is thinking differently. Spirit Mountain, outside Duluth, Minn., began loading fat bikes on its lifts alongside skiers and boarders last January, giving fat-bike riders downhill access similar to that which its bike park offers in the summer.

“We already have plenty of groomed access in the city,” says marketing director Jody Ream, referring to Duluth’s 35 miles of maintained Nordic trails. “But at the resort, we have a unique opportunity to throw downhill into the mix.”

Still, there are limitations. Spirit allows fat bikes lift access on Sundays only. It began to experiment by closing off Juggler Joe, a green/blue ski run, to ski traffic that day and allowing fat bikes only. But the area soon began to integrate fat bikes into the general downhill traffic, with no ill effects. “Everyone’s played really well together,” says Ream.

Fat bikes are now allowed to share two ski runs (Timber Cruiser and Juggler Joe) with skiers and boarders, and also have exclusive access to 75 percent of the snow-covered downhill mountain bike trail network, which includes features such as jumps, berms, rollers—even cliff drops.

“It’s just something you don’t get to do everywhere,” says Ream. “And the numbers have been very solid since the beginning.”

He says that Spirit’s top day saw more than 75 lift tickets sold to people riding fat bikes. About 50 tickets are sold to bike riders on an average Sunday.

“We’ve seen fat-bikers from eight to 10 different states,” says Ream. “We’ve had people come from as far as Omaha and Manhattan [Kansas] to load fat bikes on our chairlift.”

There are a few practical issues to address. At Spirit, fat-bike riders get their own line for uploading, bikes are hung from the same side hooks used for bikes in the summer, and riders load with skiers and snowboarders. As a sign of how well the mixed-use integration is going, some patrollers are rolling fatties.

What’s Next?

Grand Targhee and Crested Butte both say they are evaluating the demand, risk, and resources for putting fat bikes on chairlifts for downhill access, but as of now, there’s no indication they will do so for the coming season.

Regardless of how fat biking is handled going forward, it’s clearly growing in popularity. As a result, many resorts are evaluating how to incorporate two wheels in the winter months—a situation most operators would have laughed at only a few years ago.

Will most who choose to embrace this new user group integrate fat bikes among Nordic and uphill users? Or is Spirit Mountain perhaps at the forefront of a new industry trend?

It’s entirely possible that Spirit is on the cutting edge. “The Duluth area is a winter Mecca for outdoor activities, and the fat biking scene has just exploded here,” says Ream. “We’re positioned exceptionally well to be progressive and innovative in where this respective industry is going.”

Regardless of whether fat bikes are a growing trend with huge upside, or a temporary fad like, say, snowblades, their current popularity has earned the attention of resort operators. Who knows where it’ll be 10 years from now. But one thing is for sure: at present, this new sport is gaining traction.