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