Dotsero Crater is a 700-meter wide by 400-meter 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.Crater caused by Dotsero eruption. the site is a point of interest for hikers. This Holocene volcano erupted in the year 2220 BCE, give or take 300 years. When Dotsero blew, it created small scoria cones that were constructed along a NNE-SSW line on either side of the maar. The eruption date is based upon radiocarbon dating of wood found underneath some of the scoria. 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. Interstate 70 cuts across the lava flow. The main industry at Dotsero for years consisted of making cinderblocks from the volcano