Devils Kitchen in the Lassen Volcanic Region (within the bounds of the Lassen Volcanic National Park) is the second largest of Lassen's hydrothermal areas, after Bumpass Hell. Located in the Warner Valley in the southeast corner of the Park, Devils Kitchen contains boiling springs, mudpots, hot streams, and steam vents. USGS photo courtesy of Deb Bergfeld
When did Lassen Peak last erupt?
The most recent eruptive activity at Lassen Peak (California) took place in 1914-1917. This eruptive episode began on May 30, 1914, when a small phreatic eruption occurred at a new vent near the summit of the peak. More than 150 explosions of various sizes occurred during the following year.
By mid-May 1915, the eruption changed in character; lava appeared in the summit crater and subsequently flowed about 100 meters over the west and (probably) east crater walls. Disruption of the sticky lava on the upper east side of Lassen Peak on May 19 resulted in an avalanche of hot rock onto a snowfield. This generated a lahar that travelled more than 18 kilometers down Lost Creek.
On May 22, an explosive eruption produced a pyroclastic flow that devastated an area as far as 6 kilometers northeast of the summit. The eruption also generated lahars that flowed more than 20 kilometers down Lost Creek and floods that went down Hat Creek. A vertical eruption column from the pyroclastic eruption rose to an altitude of more than 9 kilometers above the vent and deposited a lobe of tephra that can be traced as far as 30 kilometers to the east-northeast. The fall of fine ash was reported as far away as Elko, Nevada - more than 500 kilometers east of Lassen Peak. Intermittent eruptions of variable intensity continued until about the middle of 1917.
Learn more:
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Devils Kitchen in the Lassen Volcanic Region (within the bounds of the Lassen Volcanic National Park) is the second largest of Lassen's hydrothermal areas, after Bumpass Hell. Located in the Warner Valley in the southeast corner of the Park, Devils Kitchen contains boiling springs, mudpots, hot streams, and steam vents. USGS photo courtesy of Deb Bergfeld

Volcanic eruptions occur int he State about as frequently as the large San Andreas Fault Zone earthquakes. California's "watch list" volcanoes are dispersed throughout the State and future eruptions are inevitable—the likelihood of renewed volcanism is on the order of one in a few hundred to one in a few thousand annually.
Volcanic eruptions occur int he State about as frequently as the large San Andreas Fault Zone earthquakes. California's "watch list" volcanoes are dispersed throughout the State and future eruptions are inevitable—the likelihood of renewed volcanism is on the order of one in a few hundred to one in a few thousand annually.
USGS geologist Deborah Bergfeld collects a gas sample from a superheated (hotter than the boiling point) fumarole in Little Hot Springs Valley at Lassen Volcanic National Park.
USGS geologist Deborah Bergfeld collects a gas sample from a superheated (hotter than the boiling point) fumarole in Little Hot Springs Valley at Lassen Volcanic National Park.

Title: A Sight "Fearfully Grand" Eruptions of Lassen Peak, California, 1914 to1917
- A summary of the eruptions and their effects
- Illustrated with historical photographs
Title: A Sight "Fearfully Grand" Eruptions of Lassen Peak, California, 1914 to1917
- A summary of the eruptions and their effects
- Illustrated with historical photographs

Lassen Peak viewed from the south at the summit of Brokeoff Volcano, Lassen Volcanic National Park.
Lassen Peak viewed from the south at the summit of Brokeoff Volcano, Lassen Volcanic National Park.
--a wonderland of volcanoes and thermal features
By Patrick Muffler, Geologist Emeritus
--a wonderland of volcanoes and thermal features
By Patrick Muffler, Geologist Emeritus
Cinder Cone erupted in the year 1666 in the Lassen Volcanic Region of northern California.
Cinder Cone erupted in the year 1666 in the Lassen Volcanic Region of northern California.
USGS geochemist Cathy Janik (left) and Iceland Geosurvey chemist Jón Örn Bjarnason (right) collect a gas sample from a fumarole in Lassen Volcanic National Park.
USGS geochemist Cathy Janik (left) and Iceland Geosurvey chemist Jón Örn Bjarnason (right) collect a gas sample from a fumarole in Lassen Volcanic National Park.
Benjamin F. Loomis Historical Photograph Collection: Lassen Peak showing new lava flow on summit and large mudflows on slopes. Photo courtesy of NPS.
Benjamin F. Loomis Historical Photograph Collection: Lassen Peak showing new lava flow on summit and large mudflows on slopes. Photo courtesy of NPS.
California’s exposure to volcanic hazards
2018 update to the U.S. Geological Survey national volcanic threat assessment
Geologic field-trip guide to the Lassen segment of the Cascades Arc, northern California
Geologic field-trip guide to Lassen Volcanic National Park and vicinity, California
A sight "fearfully grand": eruptions of Lassen Peak, California, 1914 to 1917
The California Volcano Observatory: Monitoring the state's restless volcanoes
Volcano hazards assessment for the Lassen region, northern California
Eruption probabilities for the Lassen Volcanic Center and regional volcanism, northern California, and probabilities for large explosive eruptions in the Cascade Range
Lahar hazard zones for eruption-generated lahars in the Lassen Volcanic Center, California
Eruptions in the Cascade Range during the past 4,000 years
"Hot Water" in Lassen Volcanic National Park: Fumaroles, steaming ground, and boiling mudpots
Volcano hazards of the Lassen Volcanic National Park area, California
Related
How often does Mount Shasta erupt?
How many eruptions have there been in the Cascades during the last 4,000 years?
Can earthquakes trigger volcanic eruptions?
How are volcanic gases measured?
How can we tell when a volcano will erupt?
Is it dangerous to work on volcanoes? What precautions do scientists take?
Why is it important to monitor volcanoes?
Can lakes near volcanoes become acidic enough to be dangerous to people and animals?
Can volcanic eruptions endanger helicopters and other aircraft?
How dangerous are pyroclastic flows?
What kind of school training do you need to become a volcanologist?
What is the "Ring of Fire"?

Devils Kitchen in the Lassen Volcanic Region (within the bounds of the Lassen Volcanic National Park) is the second largest of Lassen's hydrothermal areas, after Bumpass Hell. Located in the Warner Valley in the southeast corner of the Park, Devils Kitchen contains boiling springs, mudpots, hot streams, and steam vents. USGS photo courtesy of Deb Bergfeld
Devils Kitchen in the Lassen Volcanic Region (within the bounds of the Lassen Volcanic National Park) is the second largest of Lassen's hydrothermal areas, after Bumpass Hell. Located in the Warner Valley in the southeast corner of the Park, Devils Kitchen contains boiling springs, mudpots, hot streams, and steam vents. USGS photo courtesy of Deb Bergfeld

Volcanic eruptions occur int he State about as frequently as the large San Andreas Fault Zone earthquakes. California's "watch list" volcanoes are dispersed throughout the State and future eruptions are inevitable—the likelihood of renewed volcanism is on the order of one in a few hundred to one in a few thousand annually.
Volcanic eruptions occur int he State about as frequently as the large San Andreas Fault Zone earthquakes. California's "watch list" volcanoes are dispersed throughout the State and future eruptions are inevitable—the likelihood of renewed volcanism is on the order of one in a few hundred to one in a few thousand annually.
USGS geologist Deborah Bergfeld collects a gas sample from a superheated (hotter than the boiling point) fumarole in Little Hot Springs Valley at Lassen Volcanic National Park.
USGS geologist Deborah Bergfeld collects a gas sample from a superheated (hotter than the boiling point) fumarole in Little Hot Springs Valley at Lassen Volcanic National Park.

Title: A Sight "Fearfully Grand" Eruptions of Lassen Peak, California, 1914 to1917
- A summary of the eruptions and their effects
- Illustrated with historical photographs
Title: A Sight "Fearfully Grand" Eruptions of Lassen Peak, California, 1914 to1917
- A summary of the eruptions and their effects
- Illustrated with historical photographs

Lassen Peak viewed from the south at the summit of Brokeoff Volcano, Lassen Volcanic National Park.
Lassen Peak viewed from the south at the summit of Brokeoff Volcano, Lassen Volcanic National Park.
--a wonderland of volcanoes and thermal features
By Patrick Muffler, Geologist Emeritus
--a wonderland of volcanoes and thermal features
By Patrick Muffler, Geologist Emeritus
Cinder Cone erupted in the year 1666 in the Lassen Volcanic Region of northern California.
Cinder Cone erupted in the year 1666 in the Lassen Volcanic Region of northern California.
USGS geochemist Cathy Janik (left) and Iceland Geosurvey chemist Jón Örn Bjarnason (right) collect a gas sample from a fumarole in Lassen Volcanic National Park.
USGS geochemist Cathy Janik (left) and Iceland Geosurvey chemist Jón Örn Bjarnason (right) collect a gas sample from a fumarole in Lassen Volcanic National Park.
Benjamin F. Loomis Historical Photograph Collection: Lassen Peak showing new lava flow on summit and large mudflows on slopes. Photo courtesy of NPS.
Benjamin F. Loomis Historical Photograph Collection: Lassen Peak showing new lava flow on summit and large mudflows on slopes. Photo courtesy of NPS.