The destiny of wild places in the 21 century can be read in the numbers. The pressure to exploit the world's remaining wilderness for natural resources, food and human habitation will become overwhelming. But a new menace has emerged from the least likely place: the very people who care most passionately about empty places are hastening their death. Backcountry activities have become extremely trendy in the US, a fad that has been eagerly abetted by Madison Avenue. These days it's impossible to turn on a television or open a magazine without being attacked by a barrage of ads that use skillfully packaged images of wilderness activities to encourage consumerism. Unsettling though this development may be, it happens to come with a substantial upside; because wilderness is now esteemed as something precious and fashionable, wild places are more often being rescued from commercial exploitation. But if the wilderness fad has made it easier to protect wild country from development, it has made it harder to protect wild country from the exploding ranks of wilderness enthusiasts. Increasingly, places once considered enduringly back of beyond are now crowded with solitude seekers. As wilderness dwindles and disappears, more is at stake than the fate of endangered species. Other, less tangible things stand to be lost as well. Empty places have long served for a host of complicated yearnings and desires. As an antidote to the alienation and pervasive softness that trouble modern society, there is no substitute for a trip to an untravelled patch of backcountry, with its wonders, privation and physical trials.