when did yellowstone last erupt

The last major eruption of the Yellowstone supervolcano occurred about 640,000 years ago. This eruption caused the collapse of the eruption area, creating the large caldera that is 1,500 square miles in area. Since then, there have been multiple smaller volcanic activities, including lava flows about 70,000 years ago, and other post-caldera eruptions. More recently, there have been small hydrothermal explosions, such as one recorded in 2018, but no major volcanic eruptions like the supervolcano eruptions of the distant past. So, the last supervolcano eruption in Yellowstone was around 640,000 years ago, with smaller volcanic activity dating as recent as about 70,000 years ago.