Geoff Kabush pedaled over the crest of Colorado's Tenmile Range on Thursday afternoon with a 3,200-foot descent in front of him. It would take him down a stunning section of the Colorado Trail into Frisco, where he and the trio chasing him would turn right and pedal seven miles back to Breckenridge and the finish line of the Breck Epic's vaunted Wheeler stage.

Kabush, a three-time Olympian from Squamish, B.C., was 15 seconds in front of another three-time Olympian, Todd Wells, as well as three-time Epic champ Jeremiah Bishop and reigning national champion Howard Grotts. There was a good chance the six-day, 220-mile race could be decided in the next hour of riding.

A Breck Epic Racer digs deep on top of the Tenmile Range

Already it had been the closest competition in the event's nine-year history. Grotts, who beat Wells in the Leadville 100 one day before starting the Epic, held a 25-second lead going into Stage 5. The Durango, Colorado, duo had traded the leader's jersey every day so far. It only made sense that Wells would take it back on the climactic descent, which he did.

But still the day belonged to Kabush. He put 2 minutes 22 seconds into Wells and 5:32 into Grotts, much of it on the high-speed, high-consequence Miner's Creek singletrack that numbs hands and waters eyes under four giant mountains. Kabush went on to finish in 2 hours 34 minutes for his second straight stage win.

"That's one of the hardest descents I've done. My arms were hurting way more than my legs," Kabush said. "It would've been tough on a trail bike, and trying to go flat-out on a [21.5-pound] XC bike was crazy."

The descent begins on day five of the Breck Epic.

The course reached 12,400 feet at three different points Thursday, much of it on rugged alpine trail that takes either a ton of energy and jedi skills to ride, or extra time to walk. Largely because of the scenery, this day remains the event's showcase stage, climbing 5,600 feet in just 24 miles—nearly twice as many feet per mile as the rest of the stages—against a backdrop of 13,000- and 14,000-foot peaks.

Wells, a two-time Breck Epic champ, never faced a serious challenge before this year, winning by nine and four minutes in 2013 and 2017, respectively. The result of having four men within 3:53 of the lead (Wells leads Kabush by 1:12 and Grotts by 2:44) has been a daily pace that's left them tattered. Kabush said he was too tired to stand up in the shower after stage 3. "It's just, like, a bar brawl every day," Wells said. "We're beating each other up."

There are unique factors at play, as well. According to Bishop, "Because of the altitude, you're literally looking at 60 percent power. Your peak output at Transalp"—a premier stage race in Europe where Bishop took third last month—"is 375 watts per hour. And here it's around 290. But also, this race has about five times as much singletrack as Transalp. It's a lot more advanced and the skill level is higher."

Even the women's field, which saw first-time stage racer Erin Huck leading Czech Olympian Katerina Nash by 21 seconds going into Stage 4, has been tighter than normal. Nash has since fallen off the pace by 11 minutes, but Huck, the 2016 national champion, is far from comfortable. "It's a lot harder than anything I've done before," she said. "The days are long. It's a brutal test of your physical and mental abilities."

A much needed recovery beer.

How has she recovered? "I just lay in bed, basically, and moan for a while. Eat as much as I can, which isn't that much."

"It's been more mental than anything," Kabush said. "Getting up this morning, and the body's saying, 'Don't do this, go back to bed, what are you doing?' Any other time we'd just take a week off right now—but we still had two more stages to go."

Friday brings the finale, a 30-mile route over Boreas Pass and the Continental Divide then down the Gold Dust Trail. A long dirt-road climb before the final descent would seem to favor Grotts, who is known for his ability to pull away on precisely that kind of ascent—one of the reasons he's America's best hope at next month's world championships.

"I don't know if it's possible to bring back that much time," Grotts said of his 2:44 deficit to Wells, "but I'll go for it."

Said Wells: "I have no idea what's going to happen tomorrow, but I'll just be happy to be done riding. I'm pooped."