Volcanoes in Colorado

Colorado has a rich history of volcanic activity, though it doesn’t have many volcanoes any longer. It is home to one active volcano, and that volcano had one of the biggest eruptions in history.

Around four thousand years ago, the Dotsero Volcano erupted and belched out enough ash and lava to alter the landscape. There is a massive difference between types of volcanoes, so let’s explore them.

Types of Volcanoes

The initial classification of a volcano would be if it were active, dormant, or extinct.

• Active Volcano: a volcano with a history of eruption and shows signs that it can happen again.
• Dormant Volcano: a volcano with a history of eruption and may not show signs but could erupt in the future.
• Extinct Volcano: a volcano that shows no signs of eruption and has no recent history of such.

Once we have established what classification a volcano is, we have different categories or types of volcanoes. There are five main categories to look at:

• Cinder Cone Volcanoes: Built from pyroclastic material that is pushed upward during an eruption. They often resemble a cone-like shape in your classic volcano imaginings.
• Complex Volcanoes: This is an excellent middle stage for a volcano when they’re growing or shifting into something else but are more than the basic new volcano.
• Composite/Strato-Volcanoes: When fissures open up, and magma spills out, strato-volcanoes form. They spread out and usually have multiple vents to help their growth. They are relatively short.
• Shield Volcanoes: One of the more common types, these grow out in a shield shape as the lava spreads and claims more ground.
• Spatter Cone Volcanoes: these volcanoes shoot out lava and fragments of material, but their cones are pieces welded together from the force of the heat.

The volcanoes of Colorado all have something pretty significant in common: they are all cinder-cone volcanoes. This means they all appear as your classic, mountainous volcano. They are the type of volcano you’d build for a science competition.

What is a Maar?

First, we will talk about the most prevalent volcano in Colorado: Dotsero. 

Dotsero is the active volcano present in Colorado, and it is actually a maar. A maar is formed when a volcano has a shallow eruption, meaning it doesn’t spit outside the top of the volcano. 

Water leaks out and makes steam with the magma, forcing the eruption. That forms a crater up near the top; thus, it becomes a maar. These often fill with water since it’s at the water level.

Crater Lake of Oregon is similar, as it formed its own lake within the volcano. It is the deepest lake in America and has the most transparent water in the world as it is unpolluted.

Just imagine being able to see into the depths of a volcano and glimpse the magma churning below. 

Dotsero

The legend goes that this volcano is named Dotsero by the indigenous culture which resided there in the past. It supposedly means “something new,” as they may not have ever seen a volcano until the first eruption. 

Imagine what it must have been like to feel the rumbling beneath your feet and then watch as a mountain began to spew liquid fire and clouds of ash. It must have been magnificent and terrifying all at once.

At the base of Dotsero, there is much fresher, nutrient-rich soil. Over the years, this is lava that became fertile soil, richer than other soil in the area. This could also be the narrative behind “something new.”

At about half a mile wild, the Dotsero crater is impressive to witness. It is more than 1300 feet deep and has lava flowing down at the bottom.

When driving along the interstate, one can come across Dotsero and know it immediately for what it is. The original lava flows from that eruption more than 4000 years ago can be seen as they are fossilized over the land, much in the way of Pompeii but with less known tragedy.

Will Dotsero Erupt?

As an active volcano, there is always the threat that it could erupt. Unlike other active volcanoes, if Dotsero were to go off in Colorado, it would be more of a contained eruption with the magma spreading outwards slowly instead of a vast, cataclysmic boom.

Despite being active with a recent eruption history, the United States Geological Survey has only labeled Dotsero as a “moderate” threat. If a volcano has erupted in the last 10,000 years, it is usually classified as active.

When a volcano is active, they hoard magma within themself, and eventually, the gasses and magma become too much for the space, and the volcano erupts. Sometimes it’s due to that, and other times it can be due to earthquakes or other natural phenomena.

As you can see, not all active volcanoes are the same. So many environmental factors are relevant when discussing volcanoes and their differences.

There is no reason to believe that Dotsero is a threat at all currently. For those in Colorado, there is no reason to worry. Volcanoes did much to shape Colorado, but that is all in the far past. 

McCoy and Willow Peak Volcanoes

Both McCoy and Willow Peak are extinct cinder cone volcanoes in the vicinity of Dotsero. Since they are extinct, there is next to no information regarding past eruptions or lava flows.

These volcanoes just happen to be the only other two that have retained their sizable looks. The forces of nature have not yet eroded them into volcanic fragments, which has happened to many of the other volcanoes in the Colorado region.

Willow Peaks lava flows date about 4,000 years sooner than Dotsero’s, so we know it is a bit older than the one active volcano left here.

The lava flows that coated the Colorado thousands of years ago turned it into such a rich environment today. The lava shaped the mountains and valleys, and over time the bedrock turned to new land and grew the lush forests and habitats of Colorado we are used to.

Up Next

• What Lives at the Bottom of a Volcano?
• Volcanoes in the United States
• Volcanoes in Alaska

The photo featured at the top of this post is © marekuliasz/Shutterstock.com