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Below is a summary of eruption dates and Volcanic Explosivity Indices (VEI).

The following references are the sources used for data regarding this volcano. References are linked directly to our volcano data file. Discussion of another volcano or eruption (sometimes far from the one that is the subject of the manuscript) may produce a citation that is not at all apparent from the title. Additional discussion of data sources can be found under Volcano Data Criteria.

Bass N W, Northrop S A, 1963. Geology of Glenwood Springs quadrangle and vicinty, northwestern Colorado. {U S Geol Surv Bull}, 1142-J: 1-74

Larson E E, Ozima M, Bradley W C, 1975. Late Cenozoic basic volcanism in northwestern Colorado and its implications concerning tectonism and the origin of the Colorado River system. {Geol Soc Amer Mem}, 144: 115-178

Leat P T, Thompson R N, Dickin A P, Morrison M A, Hendry G L, 1989. Quaternary volcanism in northwestern Colorado: implications for the roles of asthenosphere and lithosphere in the genesis of continental basalts. {J Volc Geotherm Res}, 37: 291-310

Smith R L, Shaw H R, 1975. Igneous-related geothermal systems. {U S Geol Surv Circ}, 726: 58-83

A small maar and scoria cone complex at Dotsero, near the junction of the Colorado and Eagle Rivers west of the Gore Range, is the only Holocene volcano in Colorado. Although Interstate highway 70 cuts across a lava flow from Dotsero, this volcanic center is one of the least known in the western United States. The most prominent feature of the Dotsero complex is a 700 m wide and 400 m deep maar that was erupted about 4150 radiocarbon years ago along a ridge consisting of evaporites and reddish oxidized sandstones of Pennsylvanian age. Small scoria cones were constructed along a NNE-SSW line on either side of the maar. Small lahars preceded eruption of a basaltic lava flow that traveled 3 km down two narrow V-shaped valleys and spread out onto the floodplain of the Eagle River, diverting the river to the south side of the valley. Older Pleistocene basaltic lava flows occur nearby at Willow Peak, McCoy, and Triangle Peak.