The 4 Volcanos Surrounding Northern California Are Some Of The Most Dangerous in America

Photo by Jeffrey Eisen

It’s no secret – we have some active volcanos in our area. But are you aware that we have four of the most dangerous volcanos in the United States right in our own backyard?

National Geographic released an article highlighting the ten most dangerous volcanoes in America – Lassen Peak, Mt. Shasta, Crater Lake and South Sister Volcano in Oregon were all highlighted. You can read the whole article here.

In the article Crater Lake comes in at number 10, Lassen peak is seventh, South Sister is sixth and Mt. Shasta ranks the fifth most dangerous volcano in the U.S.Here are a few interesting tidbits from the article:

  • It called the Northern California volcanoes a “volatile cluster”
  • Crater Lake was created by a blast that had 50 times the volume of magma than the St. Helen’s eruptions
  • South Sister and Mount Shasta were both ranked as a “very high threat” by the U.S. Geological Survey
  • Mount Shasta is a particularly dangerous threat due to its proximity to “thousands of homes”
  • Lassen Peak might not erupt but geological activity could create a new volcano altogether nearby

Here’s what the article had to say about each volcano:


A lava outcrop juts from the rim of Oregon‘s Crater Lake. Born of a blast that expelled more than 50 times the volume of magma as the Mount St. Helens eruption 30 years ago, this watery caldera is also the United States’ tenth most dangerous volcano, according to the U.S. Geological Survey (USGS).

Of the 169 geologically active volcanoes in the U.S, 54 volcanoes have USGS threat levels  of “high” or worse, based on perceived explosiveness and what’s at risk near the volcano.

Mother Nature, though, can reshuffle the ranking at any time. “A volcano can be quiet for a long time, and we would give it a low threat level,” said John Eichelberger, coordinator of the USGS Volcano Hazards Program. “But it can surprise us.”

For instance the long-gone Mount Mazama volcano cluster staged quite a surprise when it exploded 7,700 years ago – the largest Cascade Range eruption of the last hundred thousand years. Water eventually filled the resulting three-mile-wide (eight-kilometer-wide) wide crater, forming Crater Lake.

“You could look at that as a system that exhausted itself,” said William Scott, a geologist at the USGS Cascades Volcano Observatory in Vancouver, Washington. “It’s been quiet for the last 5,000 years.” (See Crater Lake National Park travel guide).


It might be slightly unfair to single out Lassen Peak, since the Redding, California-area volcano (map) is simply one among several volcanoes in a volatile cluster.

“The next eruption might not be on Lassen Peak,” said the Cascades Volcano Observatory’s Scott. The blast could take place at a neighboring volcano – or create a new one altogether.

Lassen Peak last erupted during between 1915 and 1917. Like Mount St. Helens 30 years ago, the California volcano blew down a patch of forest, but on a much smaller scale. The previous eruption in the area – called the Lassen Volcanic Center – in the mid-17th century formed a new volcanic cone about 10 miles (16 kilometers) east of Lassen Peak.


With South Sister (pictured) ranked by the USGS as a “very high threat” volcano, the Three Sisters area is a volcanic hotbed spanning about 115 square miles (300 square kilometers) just west of Bend, Oregon.

The next major activity in the area might not be an eruption of one of the three volcanic peaks – Middle, South, and North Sister – but the start of a new volcano altogether, the Cascades Volcano Observatory’s Scott said. “It could really occur almost anywhere in that broad area.”

In the late 1990s and early 2000s, an area of ground west of the Middle and South Sister started to deform. Volcanologists closely monitored the 9-mile-wide (15-kilometer-wide) area they dubbed “the Bulge,” since ground deformation can indicate magma moving and accumulating underground.

The Bulge, though, is now deflating. “In the end, it didn’t result in an eruption,” Scott said. “But it may be evidence of a process that may eventually produce one.”


Flanked by an interstate, California‘s Mount Shasta volcano looms over thousands of homes, a key to its USGS “very high threat” rating (more California volcano pictures).

Around Mount Shasta an eruption’s pyroclastic flow – rapid currents of superheated gas, ash, and rock caused by a volcanic explosion – as well as ash-infused mudflows could put towns and infrastructure in harm’s way.

The last reported eruption was seen from the Pacific Ocean in 1786 and may not have “been such a big deal,” the Cascades Volcano Observatory’s Scott. “We haven’t had [an eruption] since settlement by European settlers, but in the geologic sense the volcano has been quite frequently active.”

There you have it. We live in a volcano smorgasbord! Luckily, it seems that modern-day technology will allow us to predict dangerous volcanic activity and get to safety. But it’s fun to imagine what it’d be to see the beasts erupt. Maybe in our lifetime…

Active NorCal

Telling the Stories of Northern California
Back to top button