A group of mountain bikers ride together up a cinder road from the Scout Lake day-use area near Sisters during the final day of The Big Fat Tour on Sunday morning.

There is nothing easy about the Big Fat Tour.

It is three days of mountain bike riding, and its total distance of more than 150 miles includes countless stretches of elevation gain high into the snow-frosted Cascades. The event, now in its 15th year, is not for the weak at heart. Nor is it for the occasional mountain biker. The Big Fat Tour is for riders who hit the trails all summer long, for those who love meeting goals no matter how challenging, and for those who covet the Epic patch — the reward for completing all three days of the tour’s long rides.

“It’s really friggin’ hard,” said Woody Star, one of the event organizers and chairman of the Central Oregon Trail Alliance, a nonprofit that works to build and maintain trails in the area and also a beneficiary of the Big Fat Tour.

“I think it’s been the hardest year ever,” added Dave Landolt, 53, of Vancouver, Wash. Landolt said he has made the trip to Central Oregon to ride in the Big Fat Tour with a group of friends for the last several years, as do many others from areas in Southern California, Canada and the East Coast. The rest of the participants in this year’s tour — 175 in all — came from areas around Oregon.

The Epic participants (a shorter Recreational option also was offered) rode 50 miles Friday from Paulina Falls in Newberry Caldera to Sunriver Resort, then 80 miles Saturday from Shevlin Park west of Bend up and around Mount Bachelor, up to Dutchman Flat and then back down to Shevlin Park. Finally, Sunday’s ride was a 26-mile loop northwest of Sisters from Scout Lake to the summit of Cache Mountain.

“I don’t think it’s any harder than it’s ever been,” said Paul Thomasberg, founder of the tour and the man responsible for setting the courses. “Every year is different. And mainly we are trying to do different routes, so we never know how hard it’s going to be until we actually do the route.

“At the beginning of (the Big Fat Tour 15 years ago), part of it was about putting people in a situation to be able to ride longer than they’ve ever ridden before. … ‘Look you can do this. We’re going to have people out there to help you. … We’re going to have good food at the aid stations.’ ”

During this year’s tour, 35 volunteers manned aid stations along each course, providing full meals and bike maintenance.

“I think I’ve done 13 out of the 15 (Big Fat Tours),” said Mike Beall, 58, of Bend, who has guided the tours for the last several years. “They put together a great course this year and it was not a gimme (easy). A lot of people were saying that the last two days were probably the hardest two days so far of the Big Fat.

“And it was. It cooked a lot of people.”

The full Epic tour was said to be so challenging that even Adam Craig, an Olympic mountain-bike racer from Bend, confessed that it wore him out.

“We started riding at 7:30 this morning and we got here at 4:30 (p.m.), so what’s that, nine hours on your bicycle?” said Craig, 28, at a celebration of the tour held Saturday evening at Aspen Hall west of Bend. “I’ll be tired next week. … But after having ridden the last two days, as I was riding back to my house — I just live up the street — I was kind of smiling and thinking, ‘Man, this was a really fun day. I need to prioritize this event from here on out.’ And I think most people in this room are thinking that right now.”

Riders are drawn back to the Big Fat Tour year after year, for reasons they can’t always explain.

“I don’t know, because it’s so hard,” said 11-year tour participant Anna Vacca, a resident of St. Helens north of Portland who builds trails for a living. “Sometimes doing it you are like, ‘Oh my God, I’m not going to do this next year.’ But I always do the full Epic to get the T-shirt, or now they have a patch, and bragging rights to all my buddies. And for a long time I was the only woman that did it. … But now it’s great. There’s a bunch of women that do it.”

“It’s a celebration of mountain biking,” said tour participant and volunteer Melanie Fisher, whose Bend company, Cog Wild Bicycle Tours, is a sponsor of the Big Fat Tour. “And it’s a celebration of the mountain biking community … and the joy of getting out on your bike and enjoying just pushing yourself to ride long distances.”