The Yaak Valley of northwestern Montana is one of the last great wild places in the United States, a land of black bears and grizzlies, wolves and coyotes, bald and golden eagles, wolverine, lynx, marten, fisher, elk, and even a handful of humans. It is a land of magic, but its magic may not be enough to save it from the forces threatening it now. The Yaak does have one trick up its sleeve, though: a writer to give it voice. In Winter Rick Bass...