National Geographic expeditions expert Casey Anderson leads viewers on a trek from the bottom of the Grand Canyon to the Arctic Ocean, and to many places in between, on a search for rare and endangered species such as wolverines, mountain lions, black bears and polar bears. In the episode ``Wolverine King,'' for example, Anderson manages to forge a unique face-to-face bond with Jasper, a captivity-raised wolverine, to separate fact from fiction and learn the truth about these notorious carnivores. And in ``Grand Canyon Safari,'' Anderson observes condors, rare Kaibab squirrels, tree frogs, rattlesnakes and chuckwalla lizards in their natural habitats.