Yellowstone is no ordinary wilderness. It has the distinction of being the worlds' first national park and is a lost world of vast plains, lush meadows and endless forests defended on all sides by towering mountains. It is the most extensive thermal area on earth with more than 10,000 boiling springs, fumaroles and bubbling mud pots and more geysers than the rest of the world put together. It's these strange natural wonders that first made Yellowstone famous and still make it unique today. It is also the natural beauty of Yellowstone combined with its iconic inhabitants that attract millions to visit every year. Home to America's last great Bison herds, the grizzly bear and realm of the grey wolf, this landmark series reveals the grandeur of this unique place as its animals struggle to survive over the course of the vividly changing seasons. The daily struggles of the wildlife are intimately linked to Yellowstone's greatest secret: that sleeping right beneath the snow is probably the world's largest volcano. The fate of everything in this extraordinary wilderness is in the hands of forces more powerful than we can possibly imagine.