Think of the Sky Island Scenic Parkway, as a kind of time machine. No, really. Let yourself go a minute and imagine a landscape that compresses an extraordinary range of topography into one 30-mile stretch of road. The road, known as the Mount Lemmon Parkway, does just that. It takes visitors through five life zones, from Sonoran Desert lowlands all the way up to a mixed-conifer forest, the geographic equivalent of traveling from Mexico to Canada.