Yellowstone National Park is one of the most dangerous geological features on Earth. In trying to uncover the processes behind Yellowstone's main attractions like "Old Faithful," geologists came to the frightening realization that Yellowstone was in fact a vast hidden super-volcano -- one that is overdue for a massive eruption. Yellowstone has been on a regular eruption cycle of 600,000 years but the last eruption was over 640,000 years ago, so the next is overdue. An eruption at Yellowstone could be 2,500 times the size of the 1980 Mount St. Helens event. In the past 16.5 million years, the volcano has mysteriously moved 100's of miles though Nevada across southern Idaho to reach it's present loaction in Yellowstone. But even today it is still active. A swarm of 500 earthquakes hit the park early in 2009 and geologists found that the entire Park is being pushed up into the air by hidden forces under the ground. Is this sleeping giant beginning to stir?