Yellowstone National Park was the first national park in the world. As many geologists know, Yellowstone Caldera is the largest supervolcano, a volcano capable of producing a super volcanic eruption with ejecta greater than 1,000 cubic kilometres (240 cubic miles), on the North American continent. The caldera is considered an active volcano; it has erupted with tremendous force several times in the last two million years. Showcase educational, scientific attitude with any of these gifts featuring "How Yellowstone Works" from a geological point of view. Memorable gifts for all fans of Yellowstone and supervolcanoes!