Sure, Las Vegas is home to some of the most stunning interior spaces in the world. But we’re not just a city of indoor folk who commute between desk, couch and casino. We’re also a city of outdoor adventurers. Meet six Southern Nevadans who explore the wild places beyond the edges of suburbia. They climb to mountainous heights, paddle down the Colorado River, overcome their fears and push physical limits. Each confronts the sublime in a unique way—and hopefully compels the rest of us to discover our own adventures.

Are they best friends or bitter rivals? For race partners Chris Nuñez and Nevin Wright, perhaps it’s possible to be both. “We unintentionally pace each other, because we’re so competitive,” Nuñez says, describing one of the many races they have run together. “The difference between us was seconds,” Wright adds. He’s the tall, stoic one, a union laborer and construction foreman.

“We were running to the finish line, pushing each other, fueling each other’s fire,” says Nuñez, who works in retail inventory. He’s the outspoken one who feels antsy sitting still; he’d rather be outside. They’d both rather be outside.

Two years into their friendly rivalry, they finish each other’s sentences. The guys practice about 12-15 hours a week. When they can’t compete in person, they track each other’s activity on their watches.

Such dedication was born of personal loss. In 2007, Wright’s son died. Athletic but lazy, Wright didn’t want to “sit around and be what [he] was.” So he got active. Then in 2012, Nuñez was diagnosed with multiple sclerosis. After what he called “a year of self pity,” he got involved with racing. That’s when they found each other. “The best therapy I’ve ever experienced is just being out somewhere new and beautiful, putting in work,” Wright says.

This year, both purchased annual passes to the king of all obstacle races: Spartan. Their goal is to complete about 30 races this year. More than halfway there, they travel most weekends. And sometimes they run races twice, just for the heck of it. “Everyone has their own thing, and we’re just crazy enough to let this be ours,” Nuñez says.

“I just really enjoy it,” Wright says. “My favorite is the starting line. You get all the nerves. Looking around, everybody is pumped up. The unknown is quite a rush. Then they yell ‘go,’ and everybody starts going. It’s a great feeling.”

Obviously, “enjoyment” is subjective. In Spartan races, participants run as far as 14 miles and battle up to 35 obstacles, climbing ladders, scaling walls, traversing monkey bars, leaping over fires, crawling under barbed wire and worse. “Spear throw is my nemesis,” says Nuñez, who does target practice in his own backyard.

He and Wright hope to advance to the elite wave of races, for which they’ll need to improve their time by about 20 minutes. How will they do it?

Nuñez: “You gotta try harder, run faster, get stronger.”

Wright: “A lot of hill training.”

Nuñez: “Luckily, we live in a beautiful area with plenty of hills.”