Established: August 9, 1916
Size: 106,372 acres
On June 14, 1914, three men climbed Lassen Peak to see why a seemingly dormant 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 three miles long. Above the havoc, a cloud of volcanic steam and ash rose 30,000 feet.
Eruptions of steam, ash, and tephra continued until June 1917, when the volcano resumed its quiet profile, with minor steam clouds occasionally reported. Since 1921, Lassen Peak has remained quiet. But it is still considered an active 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 terrain around St. Helens.
How to Get There
From Redding (about 45 miles away), take Calif. 44 east to Calif. 89 junction and continue to Manzanita Lake Park Entrance; from Red Bluff, follow Calif. 36 east to Mineral, turn north on Calif. 89 to Southwest Entrance. The three other entrances—at Warner Valley, Butte Lake, and Juniper Lake—are reached via unpaved roads. Airports: Redding and Chico, California; Reno, Nevada.
When to Go
The volcanic areas are best visited in summer and fall. Heavy snows close most of the main road in winter. But visitors still enjoy snowshoe hikes and cross-country skiing at the southern and northern entrances.
How to Visit
On a one-day visit, drive the main park road, linking Calif. 89. The road, snaking across the western side of the park between the Southwest and Manzanita Lake Entrances, takes you near the major volcanic features. Explore Bumpass Hell and other sites along the way. If you can stay longer, climb Cinder Cone, an outstanding example of the results of volcanism, and, if you have the stamina for a more demanding trek, try Lassen Peak.
- Nat Geo Expeditions
Four types of volcanoes—shield, composite, cinder cone, and plug dome—can be found in Lassen Volcanic National Park, where they literally bubble and steam.