The Beginning

Kilian Jornet was drenched and tired.

Mr. Jornet, 37, was just a few days into an ambitious odyssey, a self-designed project he had named “States of Elevation.” His goal was to link, by foot and by bike, the tallest peaks in the contiguous United States — a series of 70-plus publicly accessible mountains in Colorado, California and Washington known as the “14ers” because they are all 14,000 feet or higher (symbolized on the map as ). He estimated it would take him around a month.

But now, in early September, Mr. Jornet wondered whether he could continue.

It is not often that Mr. Jornet, one of the most accomplished endurance athletes on the planet, seems susceptible to human frailties. In 2017, he reached the summit of Mount Everest twice in one week, without support or supplemental oxygen. In 2023, he climbed the 177 tallest peaks in the Pyrenees in eight days. Last year, he needed just 19 days to tackle the 82 tallest peaks in the Alps.

But now, after a long flight from Norway, where he lives with his wife, Emelie Forsberg, a former skyrunning world champion, and their three young daughters, Mr. Jornet was jet-lagged and struggling to acclimate to the high altitude of the LA Freeway in Colorado, a mountainous traverse along the Continental Divide.

Making matters worse, a steady rain left him feeling as if he were soaked through to his core.

“I just felt exhausted,” Mr. Jornet recalled in a recent interview. “It felt impossible to do one more week, let alone another month. But then the body switched, and I went from fighting to adapting.”

Climbing peak after peak in Colorado, he seemed to grow stronger as he moved west, through the Mojave Desert and into the Sierra Nevada, across Northern California and finally into the Cascades.

A small support crew in a recreational vehicle met up with Mr. Jornet periodically while he was hiking, and followed more closely during his long bike rides. He also had a rotating cast of friends and fellow athletes who joined him for parts of the project.

And, over the course of 31 days and 3,197 miles, he conquered a challenge in which, on any given day, he was completing a feat — or, in some cases, feats — that many climbers would consider a lifetime achievement in and of itself.

Colorado

16 days | 1,207 miles | 56 peaks

A couple of days before Ryan Hall, the retired Olympic marathoner, was set to meet Mr. Jornet near Crested Butte, Colo., he checked the forecast. An avid climber, Mr. Hall was alarmed enough to send Mr. Jornet a text message asking if they really wanted to tackle the Elks Traverse in a snowstorm. Mr. Jornet was not concerned.

“Yeah,” he replied via text, “we might get a little wet out there.”

The weather, though, turned out to be pleasant, and Mr. Jornet and Mr. Hall chatted throughout their 12 hours together — about their families, about training and nutrition, and even about “different levels of consciousness,” Mr. Hall said. At one point, Mr. Jornet, who is from Spain, described climbing as an out-of-body experience.

Mr. Hall was surprised to learn that Mr. Jornet did not drink coffee. His explanation? He worries caffeine will make him push too hard and hinder his ability to recover. Mr. Hall said Mr. Jornet made no mention of feeling tired or hungry during their time together.

“It was interesting to see how he managed his body and what he was putting it through,” Mr. Hall said, “and how, mentally, it wasn’t taking up any space.”

Mr. Hall also noticed that Mr. Jornet refrained from talking about the project. Instead, he seemed present. The only mountain that mattered was the mountain he was on. Mr. Jornet, Mr. Hall said, was “full of peace” — an impression that was reinforced when they reached Castle Peak, their fifth and final summit together. Not that Mr. Jornet was keeping track.

“The peaks don’t really mean anything to me,” he told Mr. Hall. “The peaks are just an excuse to be out here.”

Dakota Jones, an elite trail and mountain runner, joined Mr. Jornet for his final two days of climbing in Colorado, which started with an ascent of Mount Sneffels and a 25-mile traverse through the early hours of the night.

When Mr. Jornet awoke the next morning, he rode his bicycle several hours to the next trailhead. Mr. Jones followed Mr. Jornet’s crew in his Toyota Tacoma and prepared for the day by consuming a burrito, several doughnuts and lots of coffee.

“He’s so far beyond what the rest of us can do,” Mr. Jones said of Mr. Jornet.

At around noon, they embarked on a nearly 14-hour run through the Weminuche Wilderness, a remote area of the San Juan National Forest. By the time they reached their final peak of the day, Mr. Jornet had run out of food.

“He never said a word,” Mr. Jones said. “He just kept going. That’s Kilian.”

Mr. Jornet spent a total of 16 days in Colorado, where he made 56 summits while covering more than 1,200 miles.

Desert Ride

5 days | 877 miles

Up close, there was nothing inherently sexy about Mr. Jornet’s quest. Day after day, hour after hour, minute after minute, he was simply putting one foot in front of the other, or pedaling one stroke at a time. Mr. Hall likened him to a “metronome,” his rhythmic movements never hurried or rushed.

Mr. Jones approached Mr. Jornet as if he were part of an anthropological study: What was he capable of doing next?

“He has both the physiology to be great and the infinite discipline and focus to make the most of what he has,” Mr. Jones said. “And that’s a really rare combination.”

Mr. Jornet’s discipline was clear when, after conquering Colorado, he spent five days biking nearly 900 miles across vast expanses of the Mojave Desert. He averaged about 14 hours a day in the saddle.

He was accompanied for portions of the trip by athletes like Chris Myers, a trail runner, and Gemma Arró Ribot, a former teammate on the Spanish ski mountaineer team. But Mr. Jornet also spent a great deal of time alone, and he battled boredom, fatigue and the heat by listening to music and audiobooks.

Mostly, though, he biked as a mode of transport, as a means to an end.

California

7 days | 593 miles | 15 peaks

One of Mr. Jornet’s early challenges in California was Norman’s 13, a winding, 100-mile route that links all 13 of the 14,000-foot peaks in the Sierra Nevada. In search of some expertise, Mr. Jornet recruited Olivia Amber, a world-class trail runner who, about two weeks earlier, had done the route on her own.

Some context: Ms. Amber, 30, described Norman’s 13 as a “dream project” that she had pieced together over several years. For even the most accomplished adventurers, the route is serious business. And when Ms. Amber completed it in 89 hours (which included four hours of sleep), she became the fourth person to ever do so — and the first woman.

And then there was Mr. Jornet, fresh off hundreds of miles of bicycling through the desert, who intended to move through Norman’s 13 as just one part of a much larger project. It was difficult for Ms. Amber to comprehend.

“He’s rewriting what’s possible in the mountains,” she said, “especially with endurance feats.”

On Sept. 25, Ms. Amber was set to meet Mr. Jornet at the junction of the Taboose Pass Trail and the John Muir Trail, before their shared trek up Split Mountain. To reach him, she had to jog 12 miles while ascending 6,000 feet — and she had to do it in a hurry after receiving word that he was moving quickly.

“I honestly thought he was going to beat me there,” she said. “It was crazy.”

From the start, Ms. Amber could sense Mr. Jornet was egoless. He seemed genuinely grateful for her help. With rough weather approaching, he agreed when she suggested that he take a quick nap before leaving camp.

“I wasn’t totally sure if he was committed to sleeping,” Ms. Amber recalled.

They set out before dusk, and as they began to move through the night, heavy snow blanketed them. It was Ms. Amber’s sixth time up Split Mountain, and Mr. Jornet’s first. It hardly mattered.

“He had this feel for where we were and for the terrain even though he had never been there before,” said Ms. Amber, who accompanied Mr. Jornet for 25 snow-filled miles. “I could just feel that energy from him — a confidence that came from a place of deep understanding of how to move in that kind of environment and in those conditions.”

Of course, Mr. Jornet made it look easy, even when it was not. Later, after biking another 390 miles over two days into the Cascades of Northern California, he reached Mount Shasta — the 71st and penultimate peak of his project — where he was buffeted by an Arctic wind. He had to crawl the final 1,000 feet to the summit.

“You need to laugh in those situations and find the way to pass through,” Mr. Jornet said.

Oregon Ride

3 days | 489 miles

A few hours after summiting Mount Shasta, Mr. Jornet was on two wheels once again. He was joined by the triathlete Ian Murray for a 60-mile ride on crushed volcanic gravel before they slept just south of the Oregon border.

Mr. Jornet was by himself for the next two days as he rode 430 miles to the foot of Mount Rainier in Washington. The end was near.

When he was planning the project, Mr. Jornet worried about being hit by a car or a truck while biking. “A lot of people were telling me it would be very dangerous,” he recalled.

He and his team worked hard to locate the safest roads with the widest shoulders, and he found, to his surprise, that most drivers gave him ample space. He also was grateful for the company of his friends, new and old.

“He clearly could have done every inch of this on his own and he would have been totally fine and totally happy,” Ms. Amber said. “But he had this deeper appreciation that people showed up for him and were willing to help him.”

Mr. Jornet wanted to share the experience with those who joined him for portions of it — and with the wider world. Mr. Hall, for example, laughed whenever Mr. Jornet broke out his selfie stick. It was important to Mr. Jornet that he and his team use social media — Mr. Jornet has nearly two million followers on Instagram — to convey the beauty of the natural world and the importance of protecting it.

During his travels, Mr. Jornet saw moose, coyotes, goats, eagles, snakes and even a couple of bears from a distance. None bothered him, he said.

“We would look at each other,” Mr. Jornet said, “and say: ‘Hey, guys! How are you doing?’ And just continue.”

Mount Rainier Finale

Mr. Jornet started up Mount Rainier at dawn on Oct. 3, and it was a final test worthy of the project — a 29-mile haul up 14,320 vertical feet before he reached the summit. About 17 hours after he had set out that morning, he returned to the trailhead where his support team was waiting with celebratory slices of pizza and pickle juice shots.

After 31 days and 72 summits, Mr. Jornet’s objectively absurd project was complete. He covered 629 miles on foot and biked an additional 2,568 miles, which outdistanced this year’s Tour de France by more than 400 miles. And he did all that while amassing 403,691 feet of elevation gain.

Throughout the project, Mr. Jornet wore a smartwatch that tracked his heart rate, his mileage, his sleep totals (he averaged about six hours a night) and even something called his “recovery score,” which registered zero — yes, zero — for 17 consecutive days. (At one point, he broke his cellphone, and members of his team questioned whether he had done it on purpose.)

Mr. Jornet estimated that he had burned about 9,000 calories a day, but he managed not to lose any weight. One of his secret weapons: flasks of olive oil that he guzzled raw. By the end of his journey, he was looking forward to homegrown produce from his garden and thick slices of his wife’s sourdough bread.

The day after summiting Mount Rainier, Mr. Jornet awoke feeling disoriented. His first instinct, he said, was to reach for his bike: Didn’t he have more miles ahead of him? No, he realized, it was over. He slept more peacefully the next night.

His trek through the Alps last summer, while less physically demanding, had left him mentally drained because so many of the climbs were so challenging. His jaunt through the American West was a comparative breeze.

“It was just fun,” he said. “It was nice to ride and to run and to see the things and just to enjoy those places. And I could have gone on. I was happy to finish and go home, but physically it felt like my body was ready to continue.”

For now, Mr. Jornet plans to take a break and spend time with his family.

“But I know myself,” he said, “and I know in a couple of months that I will start to think of something else.”