When will Yellowstone erupt?

Predicting when the next eruption will occur is difficult; however, the National Science Foundation estimates the next major eruption shouldn't happen for at least another one million years. The next eruption may dump several inches of ash over a large portion of the United States and could change Earth's climate.

Around 80 minor eruptions have occurred since the last major one, and these created relatively minor lava flows. Approximately 70,000 years ago was the last time lava flowed out of Yellowstone's supervolcano, and about 640,000 years ago is when the last major eruption occurred, which created the large caldera visible today.