Come witness a brief moment in the ancient battle between the earth shaping forces of creation and destruction. Nestled within Lassen’s peaceful mountain forests you will find that hissing fumaroles and boiling mud pots still shape and change the land.
On May 22, 1915, an explosive eruption at Lassen Peak, the southernmost active volcano in the Cascade Range, devastated nearby areas and rained volcanic ash as far away as 200 miles to the east. This explosion was the most powerful in a 1914-17 series of eruptions that were the most recent to occur in the Cascades prior to the 1980 eruption of Mt. St. Helens. Lassen Peak is the largest of a group of more than 30 volcanic domes erupted over the past 300,000 years in Lassen Volcanic National Park.
Hydrothermal (hot water) features at Lassen Volcanic fascinate visitors to this region of northeastern California. Boiling mud pots, steaming ground, roaring fumaroles, and sulfurous gases are linked to active volcanism and are all reminders of the ongoing potential for eruptions in the Lassen area. Nowhere else in the Cascade Range of volcanoes can such an array of hydrothermal features be seen.
Weather plays a dramatic role at Lassen Volcanic National Park. Winter, especially, shapes the landscape; snow generally begins to accumulate each year in October, doesn't melt in most places until July, and can remain in isolated areas year round. Summer weather is more predictable, with warm, dry days, blue skies, and cool nights. Visitors to Lassen Volcanic National Park should be prepared for any kind of weather, any time of the year.