Riders Charge Across Wilds of Outer Mongolia in Grueling 620-Mile Race

ABC News Nightline
Nightline Fix

It is the longest, toughest, possibly the dirtiest, probably the most insane, horse race on earth.

ABC News “Nightline” followed 30 extreme adventurers as they tore at high speeds across the wilds of Outer Mongolia. They are attempting the fearsome Mongol Derby. And for the first time ever, most of them are women.

Among this year's competitors, three Americans. First there's Devan Horn, the 20-year-old hotshot from Houston, convinced there is only one reason to be here: to win. Lynne Gilbert is a lifelong equestrian from Virginia. At 55, she is one of the oldest contestants. And there's Tom Burk, a 23-year-old Texan college grad who recently entered the corporate workforce.

“I guess you could call it a quarter-life crisis,” he said.

With a final blessing by a Buddhist monk, it's showtime and the riders are off. There is no marked trail, no set path. Riders have a crude map, a GPS and their guts to guide them.

Over the next several days, they will charge their way through 25 checkpoints, changing horses at each one, covering at least two marathons each day on their 620-mile journey.

At each station, a veterinarian performs a thorough check-up on each rider's horse. The first thing checked is its heart rate, which needs to be at 64. Contestants are given a time penalty if their horses' resting heart rate is too high -- a sign the horse may have been overworked.

By Day 6, the Mongol Derby has taken half the riders down, including Tom. Devan and Lara Palmer-Prior, a sunny 19-year-old Brit, are locked in battle, neck and neck as they ride at a punishing pace.

After 7 days of grueling work, Devan crosses the finish line first. But then the vet has crushing news. Her horse isn't recovering. His heart rate is too high. A devastating 2-hour penalty is added to her finishing time.

Lara arrives just a few minutes later. Race headquarters confirms it. She is the winner of the Mongol Derby.

“I'm just like lucky,” she said. “I got on some horses and kicked them a bit and managed to get away without any injuries, so I got here somehow.”

With first place decided, Lynne crosses the finish line on Day 8.

If finishing this race seems to mean more to Lynne than anyone else, it just might. She had a secret reason for attempting this race.

“About 3 years ago, I woke up and got up and fell over and they found that I have a hole in my heart,” she said. “I kind of shut down for about 6 months, afraid to do anything. But you don't have to quit living because you have something wrong with you.”

Devan is at the finish line to congratulate Lynne, with a new perspective on her own heartbreak.

“That one crappy hour at the finish line does not diminish the week of work that I put in to get here,” said Devan. “What's done is done, you gotta accept it, you gotta roll on. You gotta be happy you finished the Mongol Derby.”