Crater Lake | U.S. Geological Survey
Source: https://www.usgs.gov/volcanoes/crater-lake
Archived: 2026-04-23 17:11
Crater Lake | U.S. Geological Survey
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Crater Lake
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The map displays volcanoes, earthquakes, monitoring instruments, and past lava flows.
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Crater Lake
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Crater Lake partly fills one of the most visually spectacular calderas of the world, an 8-by-10-km (5-by-6-mi) basin more than 1 km (0.6 mi) deep formed by collapse of the volcano known as Mount Mazama during a series of explosive eruptions about 7,700 years ago.
Quick Facts
Location:
Oregon, Klamath County
Latitude:
42.93° N
Longitude:
122.12° W
Elevation:
2,487 (m) 8,159 (f)
Volcano type:
Caldera
Composition:
Basalt to Rhyolite
Most recent eruption:
6,600 years ago
Threat Potential:
Very High*
*based on the
National Volcano Early Warning System
Summary
Media
Sources/Usage: Public Domain.
View Media Details
Crater Lake.
Having a maximum depth of 594 m (1,949 ft), Crater Lake is the deepest lake in the United States. Mount Mazama straddles the Cascade volcanic axis and is a cluster of overlapping stratovolcanoes that is the most voluminous Quaternary volcanic system in the Oregon Cascades. The volcano's compound edifice has been active relatively continuously since 420,000 years ago, and it is built mostly of andesite to dacite until it began erupting rhyodacite about 30,000 years ago, ramping up to the caldera-forming eruption. Excellent preservation and easy access make Mount Mazama, Crater Lake caldera, and the deposits formed by the climactic eruption constitute a natural laboratory for study of volcanic and magmatic processes. Research relating to the caldera-forming eruption has been of fundamental importance to volcanologists, helping them to understand large explosive eruptions, compositional zonation in magma chambers, and collapse caldera mechanisms. The climactic eruption is also the source of the widespread Mazama ash, a useful Holocene stratigraphic marker throughout the Pacific Northwest, adjacent Canada, and offshore.
Which U.S. volcanoes pose a threat?
December 19, 2018
Which U.S. volcanoes pose a threat?
Geologic maps lay the foundation for this virtual tour of western states volcanoes.
January 8, 2018
Geologic maps lay the foundation for this virtual tour of western states volcanoes.
First earthquakes recorded at Crater Lake by new monitoring network.
October 25, 2013
First earthquakes recorded at Crater Lake by new monitoring network.
View All
February 14, 2019
Postglacial faulting near Crater Lake, Oregon, and its possible association with the Mazama caldera-forming eruption
Postglacial faulting near Crater Lake, Oregon, and its possible association with the Mazama caldera-forming eruption
Volcanoes of subduction-related magmatic arcs occur in a variety of crustal tectonic regimes, including where active faults indicate arc-normal extension. The Cascades arc volcano Mount Mazama overlaps on its west an ∼10-km-wide zone of ∼north-south–trending normal faults. A lidar (light detection and ranging) survey of Crater Lake National Park, reveals several previously unrecognized...
Authors
Charles R. Bacon, Joel E. Robinson
By
Volcano Hazards Program
,
Volcano Science Center
,
Crater Lake
October 22, 2018
2018 update to the U.S. Geological Survey national volcanic threat assessment
2018 update to the U.S. Geological Survey national volcanic threat assessment
When erupting, all volcanoes pose a degree of risk to people and infrastructure, however, the risks are not equivalent from one volcano to another because of differences in eruptive style and geographic location. Assessing the relative threats posed by U.S. volcanoes identifies which volcanoes warrant the greatest risk-mitigation efforts by the U.S. Geological Survey and its partners...
Authors
John W. Ewert, Angela K. Diefenbach, David W. Ramsey
By
Volcano Hazards Program
,
Volcano Science Center
,
Agrigan
,
Ahyi Seamount
,
Alamagan
,
Anatahan
,
Asuncion
,
Belknap
,
Black Butte Crater Lava Field
,
Black Rock Desert Volcanic Field
,
Blue Lake Crater
,
Carrizozo Lava Flow
,
Cascade Range Weekly Update
,
Cinnamon Butte
,
Clear Lake Volcanic Field
,
Coso Volcanic Field
,
Crater Lake
,
Craters of the Moon Volcanic Field
,
Daikoku Seamount
,
Davis Lake Volcanic Field
,
Devils Garden Lava Field
,
Diamond Craters Volcanic Field
,
Dotsero Volcanic Center
,
East Diamante
,
Esmeralda Bank
,
Farallon de Pajaros
,
Fukujin Seamount
,
Glacier Peak
,
Guguan
,
Haleakalā
,
Hell's Half Acre Lava Field
,
Hualālai
,
Indian Heaven Volcanic Field
,
Jordan Craters Volcanic Field
,
Kama‘ehuakanaloa
,
Kasuga 2
,
Kīlauea
,
Lassen Volcanic Center
,
Long Valley Caldera
,
Mammoth Mountain
,
Markagunt Plateau Volcanic Field
,
Maug Islands
,
Mauna Kea
,
Mauna Loa
,
Medicine Lake
,
Mono Lake Volcanic Field
,
Mono-Inyo Craters
,
Mount Adams
,
Mount Bachelor
,
Mount Baker
,
Mount Hood
,
Mount Jefferson
,
Mount Rainier
,
Mount Shasta
,
Mount St. Helens
,
Newberry
,
Ofu-Olosega
,
Pagan
,
Red Hill-Quemado Volcanic Field
,
Ruby
,
Salton Buttes
,
San Francisco Volcanic Field
,
Sand Mountain Volcanic Field
,
Sarigan
,
Soda Lakes
,
South Sarigan Seamount
,
Supply Reef
,
Ta'u Island
,
Three Sisters
,
Tutuila Island
,
Ubehebe Craters
,
Uinkaret Volcanic Field
,
Valles Caldera
,
Wapi Lava Field
,
Weekly Update
,
West Crater Volcanic Field
,
Yellowstone
,
Zealandia Bank
,
Zuni-Bandera Volcanic Field
August 16, 2017
Overview for geologic field-trip guides to Mount Mazama, Crater Lake Caldera, and Newberry Volcano, Oregon
Overview for geologic field-trip guides to Mount Mazama, Crater Lake Caldera, and Newberry Volcano, Oregon
These field-trip guides were written for the occasion of the International Association of Volcanology and Chemistry of the Earth’s Interior (IAVCEI) quadrennial scientific assembly in Portland, Oregon, in August 2017. The guide to Mount Mazama and Crater Lake caldera is an updated and expanded version of the guide (Bacon, 1989) for part of an earlier IAVCEI trip to the southern Cascade...
Authors
Charles R. Bacon, Julie M. Donnelly-Nolan, Robert A. Jensen, Heather M. Wright
By
Volcano Hazards Program
,
Volcano Science Center
,
Crater Lake
View All
October 31, 2023
Volcanic Hazards for the Crater Lake Region
Summary of volcanic hazards for the Crater Lake region.
By
Cascades Volcano Observatory
,
Crater Lake
Volcanic Hazards for the Crater Lake Region
October 31, 2023
Volcanic Hazards for the Crater Lake Region
Summary of volcanic hazards for the Crater Lake region.
Learn More
October 31, 2023
Eruption History for Mount Mazama and Crater Lake Caldera
Eruption History for Mount Mazama and Crater Lake Caldera
By
Cascades Volcano Observatory
,
Crater Lake
Eruption History for Mount Mazama and Crater Lake Caldera
October 31, 2023
Eruption History for Mount Mazama and Crater Lake Caldera
Eruption History for Mount Mazama and Crater Lake Caldera
Learn More
October 30, 2023
Climactic Eruption of Mount Mazama formed Crater Lake
The climactic eruption of Mount Mazama devastated the terrain for tens of kilometers from the volcano, sent pyroclastic flows as far as 70 km (43 mi) down every valley heading on the volcano, and produced ash fall throughout much of the Pacific Northwest and parts of southern Canada.
By
Cascades Volcano Observatory
,
Crater Lake
Climactic Eruption of Mount Mazama formed Crater Lake
October 30, 2023
Climactic Eruption of Mount Mazama formed Crater Lake
The climactic eruption of Mount Mazama devastated the terrain for tens of kilometers from the volcano, sent pyroclastic flows as far as 70 km (43 mi) down every valley heading on the volcano, and produced ash fall throughout much of the Pacific Northwest and parts of southern Canada.
Learn More
View All
Quick Facts
Location:
Oregon, Klamath County
Latitude:
42.93° N
Longitude:
122.12° W
Elevation:
2,487 (m) 8,159 (f)
Volcano type:
Caldera
Composition:
Basalt to Rhyolite
Most recent eruption:
6,600 years ago
Threat Potential:
Very High*
*based on the
National Volcano Early Warning System
Volcanoes Hazards Program Links
Assess
Prepare
Forecast
Activity
Products
Observatories
About
Was this page helpful?
Skip to main content
Official websites use .gov
A
.gov
website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A
lock (
)
or
https://
means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Crater Lake
Find U.S. Volcano
Filters
Learn More
The map displays volcanoes, earthquakes, monitoring instruments, and past lava flows.
Get Help
Earthquake Plots
To view an earthquake cross-sectional plot, click "Draw Plot" to start drawing on the map. Once the plot area is selected, click on "View Plot" to view chart or "Clear Plot" to start over.
Map Layers
Earthquake Colors
Earthquake Depth Units
Earthquake Time Units
Results
Filters
Learn More
The map displays volcanoes, earthquakes, monitoring instruments, and past lava flows.
Get Help
Earthquake Plots
To view an earthquake cross-sectional plot, click "Draw Plot" to start drawing on the map. Once the plot area is selected, click on "View Plot" to view chart or "Clear Plot" to start over.
Settings
Map Layers
Earthquake Colors
Earthquake Depth Units
Earthquake Time Units
x
Map Legend
x
Map Legend
Results
Crater Lake
Home
Science
Multimedia
Publications
Maps
News
Connect
Crater Lake partly fills one of the most visually spectacular calderas of the world, an 8-by-10-km (5-by-6-mi) basin more than 1 km (0.6 mi) deep formed by collapse of the volcano known as Mount Mazama during a series of explosive eruptions about 7,700 years ago.
Quick Facts
Location:
Oregon, Klamath County
Latitude:
42.93° N
Longitude:
122.12° W
Elevation:
2,487 (m) 8,159 (f)
Volcano type:
Caldera
Composition:
Basalt to Rhyolite
Most recent eruption:
6,600 years ago
Threat Potential:
Very High*
*based on the
National Volcano Early Warning System
Summary
Media
Sources/Usage: Public Domain.
View Media Details
Crater Lake.
Having a maximum depth of 594 m (1,949 ft), Crater Lake is the deepest lake in the United States. Mount Mazama straddles the Cascade volcanic axis and is a cluster of overlapping stratovolcanoes that is the most voluminous Quaternary volcanic system in the Oregon Cascades. The volcano's compound edifice has been active relatively continuously since 420,000 years ago, and it is built mostly of andesite to dacite until it began erupting rhyodacite about 30,000 years ago, ramping up to the caldera-forming eruption. Excellent preservation and easy access make Mount Mazama, Crater Lake caldera, and the deposits formed by the climactic eruption constitute a natural laboratory for study of volcanic and magmatic processes. Research relating to the caldera-forming eruption has been of fundamental importance to volcanologists, helping them to understand large explosive eruptions, compositional zonation in magma chambers, and collapse caldera mechanisms. The climactic eruption is also the source of the widespread Mazama ash, a useful Holocene stratigraphic marker throughout the Pacific Northwest, adjacent Canada, and offshore.
Which U.S. volcanoes pose a threat?
December 19, 2018
Which U.S. volcanoes pose a threat?
Geologic maps lay the foundation for this virtual tour of western states volcanoes.
January 8, 2018
Geologic maps lay the foundation for this virtual tour of western states volcanoes.
First earthquakes recorded at Crater Lake by new monitoring network.
October 25, 2013
First earthquakes recorded at Crater Lake by new monitoring network.
View All
February 14, 2019
Postglacial faulting near Crater Lake, Oregon, and its possible association with the Mazama caldera-forming eruption
Postglacial faulting near Crater Lake, Oregon, and its possible association with the Mazama caldera-forming eruption
Volcanoes of subduction-related magmatic arcs occur in a variety of crustal tectonic regimes, including where active faults indicate arc-normal extension. The Cascades arc volcano Mount Mazama overlaps on its west an ∼10-km-wide zone of ∼north-south–trending normal faults. A lidar (light detection and ranging) survey of Crater Lake National Park, reveals several previously unrecognized...
Authors
Charles R. Bacon, Joel E. Robinson
By
Volcano Hazards Program
,
Volcano Science Center
,
Crater Lake
October 22, 2018
2018 update to the U.S. Geological Survey national volcanic threat assessment
2018 update to the U.S. Geological Survey national volcanic threat assessment
When erupting, all volcanoes pose a degree of risk to people and infrastructure, however, the risks are not equivalent from one volcano to another because of differences in eruptive style and geographic location. Assessing the relative threats posed by U.S. volcanoes identifies which volcanoes warrant the greatest risk-mitigation efforts by the U.S. Geological Survey and its partners...
Authors
John W. Ewert, Angela K. Diefenbach, David W. Ramsey
By
Volcano Hazards Program
,
Volcano Science Center
,
Agrigan
,
Ahyi Seamount
,
Alamagan
,
Anatahan
,
Asuncion
,
Belknap
,
Black Butte Crater Lava Field
,
Black Rock Desert Volcanic Field
,
Blue Lake Crater
,
Carrizozo Lava Flow
,
Cascade Range Weekly Update
,
Cinnamon Butte
,
Clear Lake Volcanic Field
,
Coso Volcanic Field
,
Crater Lake
,
Craters of the Moon Volcanic Field
,
Daikoku Seamount
,
Davis Lake Volcanic Field
,
Devils Garden Lava Field
,
Diamond Craters Volcanic Field
,
Dotsero Volcanic Center
,
East Diamante
,
Esmeralda Bank
,
Farallon de Pajaros
,
Fukujin Seamount
,
Glacier Peak
,
Guguan
,
Haleakalā
,
Hell's Half Acre Lava Field
,
Hualālai
,
Indian Heaven Volcanic Field
,
Jordan Craters Volcanic Field
,
Kama‘ehuakanaloa
,
Kasuga 2
,
Kīlauea
,
Lassen Volcanic Center
,
Long Valley Caldera
,
Mammoth Mountain
,
Markagunt Plateau Volcanic Field
,
Maug Islands
,
Mauna Kea
,
Mauna Loa
,
Medicine Lake
,
Mono Lake Volcanic Field
,
Mono-Inyo Craters
,
Mount Adams
,
Mount Bachelor
,
Mount Baker
,
Mount Hood
,
Mount Jefferson
,
Mount Rainier
,
Mount Shasta
,
Mount St. Helens
,
Newberry
,
Ofu-Olosega
,
Pagan
,
Red Hill-Quemado Volcanic Field
,
Ruby
,
Salton Buttes
,
San Francisco Volcanic Field
,
Sand Mountain Volcanic Field
,
Sarigan
,
Soda Lakes
,
South Sarigan Seamount
,
Supply Reef
,
Ta'u Island
,
Three Sisters
,
Tutuila Island
,
Ubehebe Craters
,
Uinkaret Volcanic Field
,
Valles Caldera
,
Wapi Lava Field
,
Weekly Update
,
West Crater Volcanic Field
,
Yellowstone
,
Zealandia Bank
,
Zuni-Bandera Volcanic Field
August 16, 2017
Overview for geologic field-trip guides to Mount Mazama, Crater Lake Caldera, and Newberry Volcano, Oregon
Overview for geologic field-trip guides to Mount Mazama, Crater Lake Caldera, and Newberry Volcano, Oregon
These field-trip guides were written for the occasion of the International Association of Volcanology and Chemistry of the Earth’s Interior (IAVCEI) quadrennial scientific assembly in Portland, Oregon, in August 2017. The guide to Mount Mazama and Crater Lake caldera is an updated and expanded version of the guide (Bacon, 1989) for part of an earlier IAVCEI trip to the southern Cascade...
Authors
Charles R. Bacon, Julie M. Donnelly-Nolan, Robert A. Jensen, Heather M. Wright
By
Volcano Hazards Program
,
Volcano Science Center
,
Crater Lake
View All
October 31, 2023
Volcanic Hazards for the Crater Lake Region
Summary of volcanic hazards for the Crater Lake region.
By
Cascades Volcano Observatory
,
Crater Lake
Volcanic Hazards for the Crater Lake Region
October 31, 2023
Volcanic Hazards for the Crater Lake Region
Summary of volcanic hazards for the Crater Lake region.
Learn More
October 31, 2023
Eruption History for Mount Mazama and Crater Lake Caldera
Eruption History for Mount Mazama and Crater Lake Caldera
By
Cascades Volcano Observatory
,
Crater Lake
Eruption History for Mount Mazama and Crater Lake Caldera
October 31, 2023
Eruption History for Mount Mazama and Crater Lake Caldera
Eruption History for Mount Mazama and Crater Lake Caldera
Learn More
October 30, 2023
Climactic Eruption of Mount Mazama formed Crater Lake
The climactic eruption of Mount Mazama devastated the terrain for tens of kilometers from the volcano, sent pyroclastic flows as far as 70 km (43 mi) down every valley heading on the volcano, and produced ash fall throughout much of the Pacific Northwest and parts of southern Canada.
By
Cascades Volcano Observatory
,
Crater Lake
Climactic Eruption of Mount Mazama formed Crater Lake
October 30, 2023
Climactic Eruption of Mount Mazama formed Crater Lake
The climactic eruption of Mount Mazama devastated the terrain for tens of kilometers from the volcano, sent pyroclastic flows as far as 70 km (43 mi) down every valley heading on the volcano, and produced ash fall throughout much of the Pacific Northwest and parts of southern Canada.
Learn More
View All
Quick Facts
Location:
Oregon, Klamath County
Latitude:
42.93° N
Longitude:
122.12° W
Elevation:
2,487 (m) 8,159 (f)
Volcano type:
Caldera
Composition:
Basalt to Rhyolite
Most recent eruption:
6,600 years ago
Threat Potential:
Very High*
*based on the
National Volcano Early Warning System
Volcanoes Hazards Program Links
Assess
Prepare
Forecast
Activity
Products
Observatories
About
Was this page helpful?