Chilean climbers, apparently bolstered by reports from an American pilot who’d flown over the area in the mid-1990s, traded stories about the valley for a few years, but it took a foreign expedition to mount the first attack. In 1997, Crispin Waddy, of the UK, made a recon, supposedly spending three epic days fighting his way from the river to the base of Cerro Trinidad with a machete. Later that same year, the UK climbers Noel Craine, Tim Dolan, and Simon Nadin climbed Stirling Moss (5.9; 1,500 feet), a somewhat unremarkable route up the formation’s northern flank.

In 1998, the true assault began: British and American teams established three routes splitting the 2,500-foot west face (and El Pie). Two teams from the UK deployed, including the return of Nadin, Waddy, and Craine, and pushed long, mixed aid-and-free routes through the roofs capping El Pie. Meanwhile, intrepid American explorers Steve Quinlan and Nathan Martin added Magellanic Clods/Welcome to the Jungle. These grade VI routes, all weighing in at the vague 5.11 A3, revealed the glory and the consequences of new routing in Cochamó. From a distance, the granite looks deliciously Yosemite-like. But up close, the cracks tend to be bottoming grooves, initially heavily vegetated, and difficult to protect. The free climbing is mostly up slabby, desperately flared cracks, and much of the beyond-vertical terrain must be aided. Still, the rock itself is pristine and plentiful, with splitters occasionally appearing.

Over the next few seasons, as word spread of the “Chilean Yosemite,” various European and North American teams showed up pretty regularly, opening impressive routes on several other walls, including Cerro Capicua, El Monsturo, and Cerro La Junta, all more than 3,300 feet. In 1999, the colorful and prolific Jose Luis “Chiquiño” Hartman, from Brazil, began making annual pilgrimages; he opened several new walls by doggedly camping at their bases for weeks and established the only free route on Trinidad’s third buttress: the 12-pitch Alendalaca (5.12a).