Lassen Volcanic National Park - California

Established August 9, 1916 106,372 acres

On June 14, 1914, three men climbed Lassen Peak to see why a seemingly dead volcano had started rumbling 16 days before. Now, peering into a newborn crater, they felt the ground tremble. As they turned and ran down the steep slope, the mountain erupted. Rocks hurtled through the ash-filled air. One struck a man, knocking him out. Ashes rained down on the men. They seemed doomed. But the eruption stopped as suddenly as it had begun, and the three men survived.

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 through the 1914 crater. A 20-foot-high wall of mud, ash, and melted snow roared down the mountain, snapping tree trunks. Three days later, a huge mass of ashes and gases shot out of the volcano, devastating a swath a mile wide and 3 miles long. Above the havoc a cloud of volcanic steam and ash rose 30,000 feet.

Since then, except for a small eruption in 1921, Lassen Peak has been quiet. But it is still a volcano, the centerpiece of a vast panorama, where volcanism displays its spectaculars—wrecked mountains, devastated land, bubbling cauldrons of mud. Until Mount St. Helens blew in 1980, Lassen's eruption was the most recent volcanic explosion in the lower 48 states. Ecologists now study Lassen's landscape to see what the future may bring to the barren terrain around St. Helens.