Fat-bike riders along the Cache Creek trail in Wyoming’s Bridger-Teton National Forest. The bikes have extra-wide tires that make it possible to ride in the snow.

Fat-bike riders along the Cache Creek trail in Wyoming’s Bridger-Teton National Forest. The bikes have extra-wide tires that make it possible to ride in the snow. (Jay Goodrich)

In first grade at St. Pius X School, Sister Thomas gave my class a free period each week to reflect upon our sins. Inspired by a library book about sea animals, I sometimes spent it daydreaming about riding a walrus, which I admired for its immensity and the fact it could swim faster than cars were allowed to drive in my neighborhood. It conjured a feeling that was equal parts ponderous and agile; atop a walrus, I would be nimble among obstacles, yet able to plow through anything unavoidable.

Almost 40 years later, I get exactly the same feeling riding a fat bike in the Bridger-Teton National Forest near my home in Jackson, Wyo. With tires five inches wide, a fat bike is tank-like rather than tottering and able to roll over almost anything in its path. The shape of its frame – similar to that of a mountain bike, but with a wider fork and hubs to accommodate the ginormous tires – makes it agile enough to negotiate flowy, single-track trails through the trees. In the snow.

The purpose of a fat bike's fatness is to allow it to stay on top of compacted snow. (For the purpose of this story, at least. Fat bikes can also be ridden on sand.) Compacted snow means many things: trails groomed for Nordic skiing, trails groomed specifically for fat biking, snowmobiling trails, trails packed down by snowshoers, and even snowy roads. Depending on how heavily compacted the snow beneath is, a fat bike can handle about two to three inches of fresh snow without "wallowing" - when tires, which can be studded or not, wash out because they can't get any purchase.

"Fat biking is a paradigm shift in your head. I spent my whole life thinking, 'I can't ride a bike in winter,' but once I got on a fat bike, a lightbulb clicked," said David Hunger.

He's known in Jackson Hole as "the godfather of fat biking" for his early and aggressive advocacy of the sport in the form of free demo days, and as the founder of Teton Mountain Bike Tours. The service offers fat-bike rentals and guided trips in the area that is home to three ski resorts, including Jackson Hole Mountain Resort, a destination resort that draws skiers from around the world.

"Fat biking and skiing are perfect counterparts," Hunger said. "We're not trying to take people away from skiing. When it's high-pressure and there is no powder, those are the perfect conditions for fat biking. Instead of a bad ski day, you can have a good day riding a bike."

Last winter, there was a two-week period when Jackson Hole didn't get any snow. Rather than be sad there wasn't any powder, I happily fat-biked every day. Starting from my house, I rode a half-mile on snow-covered streets to a trailhead in the Bridger-Teton National Forest. There, I turned onto a snow-covered, groomed single-track trail. Depending on how much time and energy I had, I would either ride a switchbacking trail through a forest of lodgepole pines to a saddle near the backside of Snow King Mountain, the small ski area just south of downtown Jackson, and soak in the views of four mountain ranges; an undulating trail on the forested hillside above Cache Creek, where I'd sometimes see moose; or alongside Cache Creek, on an old mining road that I shared with Nordic skiers, snowshoers and snowmobilers.

Then it snowed every day for a week, and I didn't fat-bike once, although, by my sixth powder-skiing day in a row, my legs were dreaming of the next dry spell and the ease and mellowness of fat biking.

The author’s fat bike on a single-track trail in Jackson, Wyo.

The author’s fat bike on a single-track trail in Jackson, Wyo. (Dina Mishev/For The Washington Post)

Not only is fat biking (usually) less physically demanding than Alpine skiing, but it's also less technically demanding. "It's a pretty easy sport, even for first-timers," Hunger said. "If you have ridden a bike somewhere in your life, you can ride a fat bike." For the easiest fat-bike ride, look for a wide, flat trail. If you want more of a challenge, seek out a single-track.

Modern fat biking's history starts in the mid-1980s with ardent cyclists in Alaska and New Mexico building fat bikes in their garages and workshops. They welded together two (or three) of the widest mountain bike rims available at the time and jury-rigged tires to create wheels that were three to four inches wide, with the goal of riding on snow (Alaska) and sand (New Mexico) without wiping out or wallowing.

Until the mid-aughts, fat biking remained the fringiest of fringe sports, appealing almost exclusively to die-hard cyclists. And because die-hard cyclists tend toward tinkering, during this time, the bikes got better: Rims and tires got wider, and they started to weigh less.

Surly, a company based in Minnesota, a state that has about 2,000 miles of trails groomed for Nordic skiers, in 2005 released the first mass-produced fat bike, the Pugsley. I bought my first fat bike in 2010. At the time, I was definitely a die-hard cyclist - competing in road-bike races for a team sponsored by a local bike shop, Fitzgerald's.

In Wyoming, the road-biking season is short, and Fitzy's team members often came together at the shop to ride on indoor bikes together. Although riding in the company of friends helped the time on a trainer pass a little more quickly, it was still never as exciting as, say, watching cheese melt in the microwave.

Then one week, as I stumbled into the shop, dragging my bike and trainer, I saw a fat bike for the first time. Thinking it some kind of Frankenbike the shop mechanics had cooked up because building a bike was more exciting than watching Fitzy team members ride their indoor trainers, I laughed so hard at it that I cried.

If my childhood Big Wheel had mated with a Mars rover and the resulting offspring went crazy for carbs - that's what I saw.

"On this bike, you can ride outside all winter," shop owner Scott Fitzgerald told me. "You'll see. These are going to be huge." I didn't believe him, but, excited by the possibility of retiring my indoor bike trainer and the probability of laughing at it all winter long, I bought a fat bike the following week.

That was a decade ago. Fitzy's prediction about fat biking becoming huge has come true. In 2012, Grand Targhee Resort, above Teton Valley, on the western slope of the Tetons, became the first ski area in the country to open its groomed Nordic trails to fat bikers. "I was able to convince the resort's senior leadership that [fat biking] is another amenity for our guests when there is not a lot of powder," said Andy Williams, Targhee's events and trail manager. In 2014, fat biking was the fastest-growing segment within the cycling industry. You could buy a fat bike at Walmart.

In 2015, Teton Valley Trails and Pathways (TVTAP) and Friends of Pathways, nonprofits advocating and fundraising for pathways in Teton Valley and Jackson Hole, respectively, began grooming summer single-track mountain biking and hiking trails for winter use by fat bikers. At the same time, Grand Targhee began grooming some of its summertime single-track trails for fat bikers. For the first time, fat bikers had trails of their own.

Fat-bike-specific trails were hugely important to the growth of the sport, because, although fat bikes are capable of riding on Nordic ski trails, if the trail conditions are not right, fat bikes ruin these trails for cross-country skiers by leaving deep gouges in the groomed snow. Because of this, Nordic centers often only allow fat bikes when "conditions permit." Trails specifically groomed for fat biking are more compacted than Nordic trails, allowing fat bikers to ride in a wider range of conditions.

Turpin Meadow Ranch opened near Moran, Wyo., in 2016 and was Jackson Hole's first destination Nordic ski resort. Although focused on Nordic skiing, the ranch's founders, former Olympians Hans and Nancy Johnstone (Hans competed in Nordic combined in Calgary, Alberta, in 1988; Nancy in biathlon in Albertville, France, in 1992) welcomed fat bikers, conditions permitting, on its 12 miles of groomed cross-country ski trails. Several years after opening, the ranch began grooming dedicated fat-biking trails.

Most recently in the area, when the Caribou-Targhee National Forest, which manages much of the public land on the western (Idaho) side of the Tetons, began working with groups to design a new system of single-track trails, TVTAP was at the table from the beginning. "It was the first time we developed a trail system for both summer and winter use. All of the trails were built to accommodate winter grooming," says Nick Beatty, TVTAP's program director.

Although initially envisioned as a resource for Nordic skiers, the website now lists fat biking as an activity and includes descriptions and details for more than 200 miles of groomed trails suitable for fat biking in Jackson Hole and Teton Valley.

The growth in fat biking is not limited to Jackson Hole and Teton Valley. Take any city - ski town or not - with snow on the ground for a couple of months of the year, and you'll probably find an opportunity to go fat biking.

In greater Minneapolis, there are groomed single-track fat-biking trails in Theodore Wirth Park and Elm Creek Park Reserve. In Williston, Vt., Catamount Outdoor Family Center rents fat bikes and grooms trails specifically for fat bikers; it also allows fat bikes on its network of snowshoe-packed trails. Methow Valley in Washington state, which has one of the country's largest networks of Nordic trails, allows fat bikes on trails in four different areas. The Chequamegon Area Mountain Bike Association in northern Wisconsin maintains more than 50 miles of trails - single-track and wider paths - for winter biking.

"It's definitely true for us in Teton Valley and seems to be the case everywhere, but if you build the trails, fat bikers will come," Beatty said. Targhee's Williams, a former TVTAP board member, said: "I knew fat biking was more than a fad, but never imagined it would have grown so much."

Last winter, instead of buying a season ski pass, I bought a new fat bike. I named it the Winter Walrus.


Where to stay:

Teton Teepee Lodge

440 W. Alta Ski Hill Rd., Alta, Wyo.


This 18-room lodge at the base of the road up to Grand Targhee is a good choice for those who want to be close to Targhee and the groomed trails and plowed farm roads in Teton Valley. From $129 per night, including breakfast.

Mountain Modern Motel

380 W. Broadway, Jackson, Wyo.


This 135-room motel in downtown Jackson is about one mile from a trailhead that connects to Cache Creek. The rooms are designed with the idea that guests are athletes who will need to dry out and store their gear. From $108 per night.

Where to eat:

Butter Cafe

57 S. Main St., Victor, Idaho


Butter Cafe, the second cafe from Amelia Hatchard and Marcos Hernandez, focuses on breakfast, brunch and lunch; the smothered cowboy burrito has coffee-braised pork belly, poblano, caramelized onions, eggs, cheddar cheese and red-eye gravy. Open daily 8 a.m. to 3 p.m. Entrees from $10.

Persephone Cafe - Aspens

3445 N. Pines Way, Suite 102, Wilson, Wyo.


This bakery is just off a part-plowed/part-groomed pathway between Jackson and Wilson, allowing for a mid-ride meal, such as a smoked trout and avocado bowl, or a sweet treat, such as a kouign-amann or oatmeal cranberry cookie. Open daily 7 a.m. to 3 p.m. Entrees from $10.

Il Villaggio Osteria

3335 W. Village Dr., Teton Village, Wyo.


In Teton Village, at the base of the Jackson Hole Mountain Resort, Osteria serves uncomplicated food inspired by the Italian countryside. Open daily for breakfast, lunch and dinner from 7 to 10:30 a.m. and 11:30 a.m. to 10 p.m. Breakfast from $10; lunch entrees from $14; dinner entrees from $26.

What to do:

Teton Mountain Bike Tours

Grand Teton National Park or Bridger-Teton National Forest


Ride little-trafficked, snow-covered roads with big views of the Tetons with a guide or rent a bike and explore on your own. Tours available daily, conditions permitting. Half-day tours (four hours) are from $300 for up to two people, $150 per each additional person; full-day tours (seven hours) $500 for up to two people, $250 per each additional person. Rates include bike and helmet. Self-guided rides: Adult and kids' fat-bike rentals available for half- or full-day tours. Rentals come with helmet, repair kit and pump. Half-day (four hours) adult rental $50; full-day (24 hours) $60. Kids' rentals $40 and $50. Bike-rack rental $25.

Astoria Hot Springs Park

25 W. Johnny Counts Rd., Jackson, Wyo.


Recover from fat biking or skiing with a soak in any of the five pools fed by natural hot springs perched above the banks of the Snake River. Reserve in advance online. Session lengths vary by time of year; check website for details. Open daily 9 a.m. to 5 p.m. Single-session pool passes $18 adults, $14 ages 2 to 12, and children under 2 free.

Fitzgerald's Bicycles

500 Hwy. 89, Jackson, Wyo.


Full-day rentals of adult bikes. Rentals $60 per day.

Turpin Meadow Ranch

24505 Buffalo Valley Rd., Moran, Wyo.


Turpin Meadow Ranch has 12 miles of groomed Nordic trails open to fat bikes (conditions permitting) and six miles of fat-bike-only single-track trails. All trails are groomed daily. The ranch's dining room is open to day-users for lunch and dinner with reservations. Trails open daily through March 12. Trail passes $15. Half-day rentals $25 per bike; full-day $40. Lodging is also available, including one- and two-room cabins and two-room, one-loft chalets. From $199 per night, including breakfast and trail passes for two.

Grand Targhee Resort

3300 Ski Hill Rd., Alta, Wyo.


Targhee has about nine miles of groomed trails that are shared by Nordic skiers, fat bikers and snowshoers and three groomed trails (totaling almost six miles) of single-tracks for fat bikers. Trail passes $20 adults, $10 ages 6 through 12, and $15 ages 65 and up. For dining, visit the Trap Bar, a bar in the resort's base area that serves unfussy, filling food. Rooms in lodges are available within walking distance from the Nordic Center and its fat-biking-friendly trails. Rooms from $175 per night.

National Museum of Wildlife Art

2820 Rungius Rd., Jackson, Wyo.


The "While They're Sleeping: A Story of Bears" exhibit, on view through May 15, highlights works featuring grizzly, black and polar bears from the museum's more than 5,000-piece permanent collection. Open Tuesday through Sunday 10 a.m. to 5 p.m., Nov. 1 to April 30; closed Monday. Admission $15 adults, $13 seniors 65 and over, first child ages 5 to 18 $8, additional children $4, kids 4 and under free.


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