Yellowstone, one of the premier National Parks in the United States, is a wonderland of text book examples of geology. It is difficult to imagine the destructive force that shaped, and continues to shape this region of northwest Wyoming and nearby states. Yellowstone owes its existence to a series of volcanic events. These massive eruptions did not occur in some obscure past when dinosaurs ruled the earth. Instead, all of the volcanic activity we see today was all formed when our human ancestors were evolving on the opposite side of earth. The series of super-eruptions that occurred here, undoubtedly had considerable impact on the earths climate, which in turn, might have had some indirect effect on our evolution as a species.