Dotsero

Dotsero is a 700-meter (2,300 ft) wide by 400-meter (1,300 ft) deep maar volcano located in Dotsero, Colorado near the junction of the Colorado River and the Eagle River. It is classified as a scoria cone with evaporitic rock, basaltic tephra, and oxidized sandstone. Erupting approximately 4200 years ago, it is the youngest volcano in Colorado.

This Holocene volcano erupted in the year 2220 ± 300 years B.C. When Dotsero did erupt, it created small scoria cones that were constructed along a NNE-SSW line on either side of the maar.[1] The eruption date is based upon radiocarbon dating of wood found underneath some of the scoria.[2] It is one of the youngest eruptions in the continental U.S. and it produced an explosion crater, a lahar, and a 3-kilometer (1.9 mi) long lava flow.[1]

Dotsero, and all volcanoes that have erupted in the past 10,000 years, are more likely to become active again. The United States Geological Survey considers it a moderate threat to impact air travel if it were to erupt.[3]

Interstate 70 cuts across the lava flow.