Although Yellowstone is still an active volcano, its last lava-producing eruption occurred about 70,000 years ago and was non-explosive. The most recent non-explosive steam eruption occurred 13,800 years ago.
Yellowstone's last supervolanco, which is a large, explosive eruption, last occurred 640,000 million years ago, with two previous explosive eruptions 1.3 million and 2.1 million years ago. Since the last supervolcanic eruption 640,000 years ago, the volcano has experienced approximately 80 non-volcanic eruptions. During a non-volcanic eruption, lava flows from the mountain, but the gas buildup is insufficient to blow the mountain's top off. Scientists do not expect an explosive eruption from Yellowstone for at least 10,000 years.