Forget the Yellowstone "Super Volcano" - did you know that Idaho's natural geology is much more awesome (and explosively violent) than any other state in the country? Or, perhaps just as remarkably, that Idaho is home to not one, but dozens of active volcanoes?
As you can imagine, the earth was very different millions - even thousands - of years ago, and the Snake River Plain was far from the gentle rural belt that we know and love today back when it was still forming. In fact, while documentaries about Yellowstone tend to give the gem of Wyoming all the glory, new research is showing that the country's oldest and most famous national park is actually just the remnant of a larger, older, and fiercer volcanic system right here in the Gem State. Here, the colossal eruptions of our neighboring state were made to look like mere blips on a radar.
Uniquely, though, Idaho's deep recesses are still frothing and boiling, ready to explode at any time. While most of this activity is concentrated in one spot, we'll also tell you about a few other places in Idaho that are ticking time bombs.
Eons ago (exact dates vary), the Snake River Plain was a hotbed of volcanic activity as North America shifted southwest.
As the continent drifted, the earth’s crust was literally ripped apart, forming the Snake River Canyon, which was further carved by colossal floods and shifting tectonic plates. Super eruptions - like the one Castleford Crossing eruption - matched or far exceeded those at Yellowstone.
Smack in the middle of this turbulent landscape, Craters of the Moon is a mysterious, almost dystopian geologic expanse - an eerie volcanic reminder of Idaho's violent origins.
Pocketed with craters, boils, caverns, cones, and domes, the grey and black basalt span of the monument looks straight out of prehistoric times.
Well... because it practically is.
But whether you visit for the winter snowshoeing, the spring flowers, or the unique underground lava tubes, one thing is for certain about this remarkable monument…
Craters of the Moon isn't an extinct volcanic area. It's only sleeping.
And yes, it will erupt again.
There are more than two dozen cinder cones at Craters of the Moon, each one a small volcano, quietly waiting.
The eruptions that took place here - a series of catastrophic events dating back far beyond recorded history - are called "fissure eruptions." Unlike "typical" volcanoes, which have a giant central vent for lava to flow from, the eruptions at Craters of the Moon occurred along cracks in the earth's crust. The explosions themselves were mild, but the basaltic lava impressive and far-reaching. Escaping, pressurized gas from the earth's core also played a role in creating the small cones seen today.
While signs of brewing explosions haven't occurred recently, geologists think that the area will become active within the next 1,000 years.
Eruption signs: earthquakes, the opening of steam vents, ground swelling, and more.
It's been 2,000 years since the last eruption. Craters of the Moon is about due for another one.
Uniquely, while Idaho is along the Yellowstone Hotspot Track (which should really be the Idaho Volcanic Belt, wouldn't you say?), Craters of the Moon isn't the only hot zone. Island Park is made of multiple formerly volcanic calderas, the Mt. Borah Scarp is the site of repeated seismic activity, and most recently, a fault line found in the high Sawtooths means that Idaho has a lot of power bubbling beneath its beautiful surface--a femme fatale if there ever was one.
Curious for more? Check out this unexpected volcano hike that you can take right here in Idaho.
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