The Creation of the Yellowstone Caldera.
Scientists can only speculate what will happen when Yellowstone erupts. The way to determine its devastation is to investigate past records of prior eruptions in the area surrounding the park along the Snake River Plain. In the past 16.5 million years, there have been at least 142 eruptions along the track from the Oregon-Nevada border to present day Yellowstone (Breining, 2007). The eruptions of the past left behind thick ash fall and hardened rhyolite fields of lava which have since leveled as a plain (NPS, 2013; USGS, 2013).