California Volcano That Obliterated Forest and Launched Ash 280 Miles Away 103 Years Ago Offers a Warning, Experts Say

Lassen Peak had been rumbling for days. Glowing hot rocks bounded down the slopes. Lava was welling up into a freshly created crater.

When Lassen Peak exploded on May 22, 1915, it sent a pyroclastic flow flying down the northeast flank of the volcano, creating a zone now known as the Devastated Area. The flow knocked trees down and destroyed everything in its path — 3 square miles of wilderness was obliterated. In this file photo, ash and smoke spew from Mt. Lassen. (Credit: National Park Service)

When Lassen Peak exploded on May 22, 1915, it sent a pyroclastic flow flying down the northeast flank of the volcano, creating a zone now known as the Devastated Area. The flow knocked trees down and destroyed everything in its path — 3 square miles of wilderness was obliterated. In this file photo, ash and smoke spew from Mt. Lassen. (Credit: National Park Service)

Then, on this day 103 years ago, it exploded in a way California would never forget. It created a gigantic mushroom cloud that reached an altitude of 30,000 feet, could be seen as far away as Eureka and Sacramento and sent volcanic ash as far away as 280 miles, reaching Elko, Nev.

It was the first volcanic eruption in the contiguous 48 states since the founding of the United States, and the last until Mt. St. Helens erupted on May 18, 1980.

And it was a reminder not only of how California is threatened by earthquakes, but how volcanoes are a part of life in a state that sits in the Ring of Fire. As the world focuses on the volcanic show in Hawaii, the Lassen Peak eruption offers a lesson of the threat closer to home.

Read the full story on LATimes.com.

A Los Angeles Times story on the volcano eruption from 1915. (Credit: Los Angeles Times)

A Los Angeles Times story on the volcano eruption from 1915. (Credit: Los Angeles Times)