West of Vail and close to I-70 is a small volcano that last erupted a little over 4,000 years ago.

This maar volcano is monitored by the Yellowstone Volcano Observatory (along with several other western US volcanoes that, while nowhere the size of Yellowstone Caldera, are still considered to be active).

Dotsero, in Colorado, has even made it to the moderate-threat level, though it isn’t likely to bother the neighbors any time soon.

Here is the Global Volcanism Program page, and recent articles from the Denver ABC affiliate and the Colorado Springs Gazette.

Featured image: Lee Siebert/Smithsonian GVP