From 1914 to early 1915, Lassen spewed steam and ashes in more than 150 eruptions. Finally, on May 19, 1915, the mountaintop exploded. Lava crashed ... Until Mount St. Helens blew in 1980 ...

But California's Lassen Volcanic National Park ... prominent Mount Shasta. While the entire expanse of the Medicine Lake Volcano is unique in many ways, the area protected by the Lava Beds ...