Gaucho conjures up an image as iconic as the word cowboy. But according to historians and anthropologists, their semi-nomadic culture disappeared at the end of the nineteenth century, and no one has seen the gauchos since. Until now. Twenty-five years ago, the government of Chile began building a road into Chilean Patagonia, one of the least-populated regions in the world. In 1995, when Nick Reding traveled down that still-unfinished road into an...