THE MOUNTAINS ARE definitely talking to Jonathan. "Feel that wind—so empowering, yeah?" he'll yell as we step onto a ridge and practically get blown off. "Power! How sick is this?" He's obsessed with every bush and berry, stopping to rhapsodize about the coolness of a frog.

No one has gotten Patagonia religion quite like Jonathan. When he was a 12-year-old in Evergreen, Colorado, his mother, Cheryl, gave him a map of South America that she'd found in a dumpster outside the school where she taught.

"I slept with it every night," he says, "and I told my mom, 'I'm driving to southern Chile, and I'm going to go live there.' And she was like, 'Great—go and do it.'" In 1993, after a semester at Maine's Colby College, 19-year-old Jonathan hitchhiked to Chile from New Mexico, where he'd been working construction, to meet up with two friends and explore the glaciers up the Valle Colonia, two days' ride from anywhere. It was here that Jonathan met his mentor, a one-eyed gaucho named Everardo "Lalo" Ojeda Diaz. (He'd lost the eye as a young man when an ember flew up from a campfire; thanks to the charity of some nuns, he'd had a fine glass one installed in its place.) Lalo was 59 when the climbers made it to his Sol de Mayo ranch. He and his wife, Maria, fed the climbers, and when the rookies stumbled back a month later, emaciated and exhausted, they took them in again. In return, the boys worked on the farm, chopping wood.

A year later, Jonathan was river-guiding in Colorado when he got a letter. It was typed by a notary—Lalo can't read or write. "My respected Jonathan," it began, "I've decided to sell my ranch. It's 840 hectares. It has 1,300 meters of wood fencing, a house that is six by five meters, a smokehouse that is four by five, and a barn that's six by six. It can maintain, year-round, 100 cows, 60 sheep, and 50 goats. The offering price is $300,000."

Jonathan left the next week. He took a plane to Santiago, another to Coyhaique, drove the eight hours to Cochrane, borrowed a horse, and rode up-valley. He told Lalo he didn't have that kind of money; Lalo said he could wait. In 1997, after four years of guiding and taking classes, he moved to Puerto Bertrand and founded PAEX as a small rafting outfit. In October 2000, with the business finally taking off, he returned. That spring, as avalanches crashed down in the high mountains, the gaucho and the gringo worked out a deal: about half the asking price (still a large sum in rural Chile), and an easement for Lalo and Maria to live there until their deaths.

"I rode out of that valley so huge," Jonathan says. "I was like, Holy shit."

Jonathan's no trustafarian. But when he moved to Chile, his father, Jim, a business consultant, took him aside. "I don't know what's going to happen," he said, "but I want you to go down there and build your empire. Go and build it." To buy the properties—first Sol de Mayo, then Palomar in 2003—they formed a 50-50 partnership, Leidich Family LLC.

"The empire thing was a weird concept for me," says Jonathan. "But having my dad say that obviously impacted me. I was like, I'm just going to climb and study glaciers. I wasn't into empires then, nor am I now. But that's what you do: You try and squeak out your little domain."