I was biking in a snow globe. Fresh flakes were falling on the tree–lined trail that stretched in front of me. What was a groomed route earlier that morning had, by lunchtime, become a powder track. Suddenly, my tires wobbled and I was rocked from upright to lying on my side.

Turns out, fresh snow and afternoon riding are not the combination you want when fat biking.

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With Vail Pass closed because of the weather, my husband and I couldn’t complete the drive back to the Front Range. Rather than wasting an entire afternoon, we decided to exit Interstate 70 at the Vail Nordic Center to finally give this growing sport a try.

Fat biking, or cycling on a suspension-less bike with wider tires, has taken off over the past decade, largely because it extends the cycling season and opens up previously inaccessible terrain, including sandy and snowy routes. In the winter, it also provides a quiet alternative to Colorado’s crowded ski resorts.

“When skiing is good, fat biking is normally not good because you don’t want new snow,” says Haley Dumke, a Minturn local who took the women’s title in the Fat Bike Worlds in January. “It’s so fun — there’s always something to do.”

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As a newbie to fat tires, I hadn’t realized the fresh pow would add a layer of slip to the trail. I’d also (wrongly) assumed my ability to ride a bike would easily translate from the road to the snow.

The weather did provide one benefit: it softened my fall. I righted my rental bike, took a deep breath and continued on. My husband and I were the only two on the trail so no one else had witnessed my spill — or my second wipeout a few minutes later.

We opted for a loop of three or so miles from the eight miles of bike–accessible trails. By the end of the outing, I was more comfortable maneuvering and riding with the bike instead of trying to control it. I was also sweating through my ski jacket. Fat biking was a legit workout, I realized. Which meant I’d earned the beer and chili that awaited me in the clubhouse.

Eager to join the fat biking trend? Try these three spots across the state

Leadville: At an elevation above 10,000 feet, fat biking in the former mining town is a serious workout. It’s also seriously fun. Those great heights mean the sport is potentially doable for six months a year. Check out the Timberline Trails behind Colorado Mountain College (the 20 miles of singletrack were built and are groomed by Cloud City Wheelers, a trail and cycling advocacy group); the eight miles of trail recently added around Turquoise Lake; and the groomed Mineral Belt Trail (ride opposite the ski track). Cloud City Wheelers also organizes the Leadville Winter Mountain Bike Series, the longest running event of its kind in the country.

Crested Butte/Gunnison: Expert riders often reply with these two words when asked where they like to ride in the winter: Hartman Rocks. This popular Gunnison park boasts groomed singletrack, heart-pumping climbs and slick descents. To the north, Crested Butte Nordic grooms six miles of fat biking trails between town and the mountain. If you want even more, there are plenty of additional backcountry options, such as Gothic and Cement Creek roads, managed by Crested Butte Mountain Bike Association. Need an excuse to visit this winter? Fat Bike Worlds are returning to the ski town in January.

Breckenridge: Gold Run Nordic Center has upped its fleet of fat bike rentals due to surging popularity and even offers a fat bike season pass so riders can play on its nine miles of groomed trails without having to pay each time. For a more DIY experience, check out grooming reports for what’s ready to ride in the local trail network. Or join Ridden for a guided tour that includes warm-up stops at Broken Compass Brewing Co. and Breckenridge Distillery.