Plants and animals that live in the mountains have to be tough. It is often cold and windy in a mountain range. It isn't an easy place to live. But for snow leopards, gray wolves, red-naped sapsuckers, whitebark pines, and mountain tapirs, the mountains are their homes. They have all found ways to survive and thrive in spite of harsh conditions. These animals do more than just live in the mountains, though. They all give back to their homes as keystone species. Keystone species are so important to their habitats that if they were gone, the whole habitat might change or even disappear. The balance of nature in the mountains depends on these keystone species.