Colorado's Dotsero Crater: A Quiet Volcano with a Surprising Past

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Dotsero Crater, located near the Colorado River between Glenwood Springs and Eagle, is Colorado's only volcano. Despite its unassuming appearance, the crater is a remnant of a volcanic eruption that occurred around 4,000 years ago, when mammoths still roamed the land. Geologists classify Dotsero as a 'monogenetic' volcano, meaning it erupted only once and then became dormant.

Why it matters

The existence of Dotsero Crater serves as a reminder that Colorado's landscape was shaped not just by ice and erosion, but also by geological chaos and volcanic activity. While the volcano is currently dormant, it demonstrates that Colorado has a more dynamic geological history than many may realize.

The details

Dotsero Crater is a subtle hill along I-70 that many travelers pass by without realizing it is an actual volcano. The last eruption occurred around 4,000 years ago, when lava flowed and ash scattered across the area. Geologists classify Dotsero as a 'monogenetic' volcano, meaning it erupted only once and then became dormant.

• Dotsero Crater last erupted around 4,000 years ago.
• The volcano erupted back when mammoths still roamed the land and humans were just beginning to settle in North America.

What’s next

Geologists continue to monitor Dotsero Crater, not because they expect it to erupt again, but because it technically could, even though there are no signs of imminent activity.