Western Colorado is Home to an ‘Active’ Volcano
When talking about volcanoes in Western Colorado, the name Grand Mesa is going to come up in conversation. Did you know, there's a lesser known and much younger volcano near Dotsero, Colo.?
The Grand Mesa is an ancient volcano, estimated to be about 10 million years old. The lesser known and considerably younger volcano is the Dotsero volcano which last erupted 4,200 years ago and is Colorado's youngest volcano and also one of the youngest in the US.
The volcano, located roughly one mile north of the town of Dotsero, isn't even close to the size of the largest in the world, but it still created a four-mile long lava flow, part of which I-70 crosses.
The Dotsero volcano was created during a phreatomagmatic eruption, which the USGS describes as an explosive interaction between water and magma which releases both steam and solid fragments.
Richard Busch took a trip to the volcano in 2015 and in a Denver Museum of Nature and Science article says the Dotsero cinder cone is 2,300 feet in diameter and the original crater was probably about 1,300 feet deep. Erosion over the years has filled the crater so it's now only a few hundred feet deep.
While the volcano isn't currently on a watch list, there is a possibility, partly because it is less than 10,000 years old, it could erupt again sometime in the distant future.
Even though the Dotsero volcano isn't likely to erupt anytime soon, the large pool of magma provides a nice benefit to people swimming and soaking in Glenwood Springs. That molten underground pool keeps the water for the town's hot springs very warm.