Juan Pablo Orrego has a score to settle. During the nineties, the Santiago, Chile–based activist squared off with Endesa, a multi-billion-dollar Spanish energy company that proposed damming Chile's pristine Bío-Bío river. For his efforts, Orrego won the prestigious Goldman Environmental Prize in 1997—and Endesa built two enormous dams on the Bío-Bío anyway. Now, as coordinator of the Chilean NGO Ecosistemas, Orrego is battling Endesa over the crown jewel of the adventure-sports world: Chilean Patagonia. Endesa Chile, a European-owned company, has partnered with the Chilean company Colbún and is proposing to clear the way for five dams on the Pascua and Baker rivers, free-flowing waterways that originate near two Patagonian icefields and run into the Pacific Ocean. The 106-mile Baker, known for glacier-fed turquoise water and rainbow trout that can exceed seven pounds, flows alongside the site of the proposed Patagonia National Park.

"They already destroyed the upper Bío-Bío, and now they want to degrade the most magnificent rivers in Patagonia," says Orrego. This is a matchup that makes David and Goliath look like a fair fight. The dam project, which would cost an estimated $4 billion, is backed by one of Chile's most powerful families, the Mattes, who are ranked 137th on Forbes's 2007 list of the world's richest billionaires. Orrego, a former professional bass guitar player who studied with shamans in Mexico, coordinates the resistance from a three-room office in Santiago. But by amassing an international legal team and allying with organizations like the Natural Resources Defense Council, International Rivers, and Spanish Greenpeace, Orrego has mounted a formidable defense. "What happened on the Bío-Bío can never happen again," he says. His solution: tapping local alternative energy like wind, solar, geothermal, and tidal power and ramping up adventure tourism. "When done right, tourism is the industry without chimneys, and it lasts forever," says Orrego. "Unlike dams."