Meanwhile, on land, the threat comes from hydropower. Thanks to the Pinochet regime, most of the water rights on the major rivers that spill into the fjords are privately owned—and by foreign corporations, no less. For the past several years there has been increasing pressure to build a series of hydroelectric power dams along the Pascua and Baker Rivers. But critics argue that dams are antiquated and unnecessary in a country with such abundant renewable energy potential. They destroy the ecosystems of the watersheds in which they are built, and running transmission lines from these dams to Santiago will require a clear-cut more than a thousand miles long.

The gravest danger to the Chilean fjords is, of course, climate change, which threatens to alter the rivers that depend on these glaciers and up­set the balance of salt and fresh water in the inner fjords. Of the 48 glaciers in the Southern Ice Field, 46 are retreating and one is stable. Only one, Pío XI, is advancing. It is almost certainly the only glacier in the world at its neoglacial maximum—its farthest reach since the beginning of the Little Ice Age in Patagonia some 400 years ago. Pío is now uprooting trees that are several centuries old. No one knows for certain why it has advanced so far and so fast over the past 80 years. It may be recovering ground that was lost to eruptions of Lautaro, the active volcano from which the Southern Ice Field radiates. Or its advance may be due to the tectonic upheaval that is lifting the Andes, or to the volatility of a temperate glacier—its ice nearly always at the melting point—in a region of very high precipitation, 30 feet a year and more. But one thing is clear. Pío XI is an anomaly in a melting icescape.

A hundred and thirty miles south of Pío XI, in Torres del Paine National Park, tourists are bused in by the thousands. They camp in tent cities and queue to cross the mountain passes. They share a sense that this national park is unique and worth protecting. In the Chilean fjords, however, there will never be crowds. Their very remoteness puts them at risk, and not just from salmon farming and hydro dams. The risk is a lack of awareness, a forgetting that places as wild as Chilean Patagonia cannot survive without protection. Creating parks and reserves—even a UNESCO World Heritage site—may make a difference. But it may also be only a change in name.