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Dotsero Volcanic Center

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Dotsero Crater, near the Dotsero railroad junction in central Colorado, is one of several volcanic features resulting from basaltic eruptions between 3,800 and 5,500 years ago (4,150 +/- 300 years B.P. radiocarbon age). 

Quick Facts

Location: Colorado, Eagle County

Latitude: 39.663° N

Longitude: 107.032° W

Elevation: 2,230 (m) 7,316 (f)

Volcano type: scoria cone, lava flow

Composition: Basalt

Most recent eruption: 4,150 years ago

Nearby towns: Dotsero, Gypsum, Eagle, Glenwood Springs

Threat Potential: Moderate*

*based on the National Volcano Early Warning System

The earliest eruptions occurred along a north-northeast trend and built scoria cones that ascend the north canyon wall of the Eagle River near where it joins the Colorado River. An ‘a‘ā lava flow issued southward from a gulch and buried about 0.7 km2 (168 acres) of the adjacent floodplain. Today, U.S. Interstate Highway 70 cuts this lava flow. Dotsero Crater formed when magma encountered water and explosively blasted a crater through the country rock, destroying part of the scoria-cone chain and showering tephra across the landscape. This tephra fallout includes a substantial amount of red sandstone bedrock fragments. Although 20 m (65 ft) or thicker around the vent, much of the tephra was blown eastward from the crater by prevailing winds. The crater today has a diameter of about 750 m (2,460 ft) and a depth of 76 m (250 ft) at low rim points. When first formed, the crater was possibly as deep as 400 m (about 1,300 ft), but has since been partly filled.


2018 update to the U.S. Geological Survey national volcanic threat assessment

When erupting, all volcanoes pose a degree of risk to people and infrastructure, however, the risks are not equivalent from one volcano to another because of differences in eruptive style and geographic location. Assessing the relative threats posed by U.S. volcanoes identifies which volcanoes warrant the greatest risk-mitigation efforts by the U.S. Geological Survey and its partners. This update

John W. Ewert, Angela K. Diefenbach, David W. Ramsey