Volcanoes

Idaho’s landscape has been shaped by many types of volcanism over millions of years. From Cretaceous intrusions associated with the Idaho Batholith, to Eocene Challis Volcanic rhyolite eruptions, to Miocene Columbia River Basalt flows, to massive caldera eruptions associated with the Yellowstone hotspot, to Quaternary basalt flows at Craters of the Moon, evidence of volcanic activity can be found throughout Idaho.

Some of Idaho’s most recent volcanic areas, such as Craters of the Moon, are still considered active and could erupt again. Volcanic hazards in the Yellowstone region are monitored by the Yellowstone Volcano Observatory (YVO), a consortium of agencies and institutions of which IGS is a member.