Is Yellowstone a volcano? Yes. Within the past two million years, episodic volcanic eruptions have occurred in the Yellowstone area—three of them major. What is the caldera shown on the park map? The Yellowstone Caldera was created by a massive volcanic eruption approximately 640,000 years ago. read more
The Yellowstone Caldera is a volcanic caldera and supervolcano in Yellowstone National Park in the Western United States, sometimes referred to as the Yellowstone Supervolcano. The caldera and most of the park are located in the northwest corner of Wyoming. The major features of the caldera measure about 34 by 45 miles (55 by 72 km). read more
For its part, the Yellowstone Caldera is roughly 30 miles long and 45 miles wide, which is considered pretty gigantic, mostly because it is the result of three eruptions. read more