EMPIRE BUILDING IS NOTHING NEW in Patagonia. The name always mentioned is Doug Tompkins, founder of the clothing and equipment company The North Face. Starting in 1991, Tompkins amassed 714,000 acres of dense fjordland north of Aysén, a tract so vast that it bisected the country. Last year he donated that land, Parque Pumalin, to Chile as a national preserve, but he still can't do anything without Chileans questioning his motives. The latest controversy is the 2004 acquisition of the 173,000-acre Estancia Valle Chacabuco by Conservacion Patagonica, a nonprofit founded by Tompkins's wife, Kris McDivitt Tompkins, the former CEO of Patagonia Inc. Chacabuco is one of the most biodiverse tracts in the region, thick with condors, guanacos, and pumas. As a ranch, it is also the town of Cochrane's biggest employer.

"Chileans are very nervous with so many gringos, because they don't understand what's happening," says Peter Hartmann, a Chilean and the regional head of Comité Nacional Pro Defensa de la Fauna y Flora, Chile's foremost green group. "They can't think that they're going to remain forever as cattle ranchers on poor land that's not for cattle. Tourist land is also productive, but not, they think, for them. They haven't seen that before."

What they have seen is decades of resource exploitation. In the fifties, homesteaders burned close to seven million acres of Aysén forests, and the blackened skeletons of trees still dot pastures and fields. These days, 52 percent of Aysén, 21,900 square miles, is protected, but Santiago increasingly looks south for its energy needs. The Spanish-owned power company Endesa owns 94 percent of Aysén's water rights. If the government's pro-development bloc gets its way, two Aysén rivers will share the fate of Chile's famed Bío-Bío, which Endesa dammed in 1996. In June 2004, Endesa announced plans for $2.5 billion in hydropower projects along the Baker and the Río Pascua, despite the huge cost of transporting the electricity a thousand miles to Santiago. In each of three proposed Río Baker scenarios—all contested by environmentalists and ranchers—Puerto Bertrand ends up underwater.

PAEX is fighting this, partly by creating tourism-based alternatives and partly by acquiring more land, a few acres here and there on the Baker to drive up prices in anticipation of an Endesa buyout. This can be delicate. "Gringo land buying is not in a good way," explains Jonathan. "They're not educating the seller on the perils of having a lot of money and no land. The guy moves to town, he buys a house, he buys his cousin a house, he loans his friend a truck, the truck gets crashed, and in two years he's got no money and he's hating it."

Jonathan's trying to do things differently. "The reason he's done so well is that he's ingratiated himself to the people," says Al Read, founder of Geographic Expeditions. "He'll go up and talk for an hour with a gaucho about things, about his ranch. That's very unusual."

Indeed, one day on the trail we spend an hour hanging out in a woodpile with an eccentric old rancher named Julio Romero, who's been hoarding wool in his house for so long, waiting for the prices to rise, that he filled it up and had to move outside. So far, guys like him are all for the trail: They don't want to see these roadless valleys flooded or mined, and they don't mind making money doing the things they're losing money doing now.

"Everybody sees the beautiful side of gaucho life," says John Hauf, who first explored these valleys with NOLS in the 1980s and whose Patagonia Frontiers lodge sits on Lago Plomo. "They don't see the hard work and sacrifice and the long, cold, lonely nights. But locals here realize that tourism is where it's at for them. It's not going to make them rich, but it's going to allow them to keep their lifestyle and, if they do a good job, slowly increase it over time."

Lalo agrees. "I'd been working, my horses burdened, for more than 30 years, and I was sick of it," he says. "And yes, I always saw that this place could work for tourism. But for that you need money."

"Some people say, ‘Those damn gringos—once they become owners they kick us out,'" Lalo tells me. "But Jonathan," he winks, "he has good behavior, up until this date."