Tucked far north in Montana, hard against the Canadian border, Glacier National Park is a rumpled and craggy masterpiece. Within the park’s 1 million acres rise rustling aspen glades, stands of an unusual evergreen—larch—that loses its needles in winter, even a temperate rainforest of Pacific red cedars, hemlocks and Pacific yew. This is the kingdom of grizzlies and wolves, wolverines and lynx, species that for many exist only in books, magazines, and nature documentaries.