Mount Mazama

Mount Mazama
Crater Lake 2.jpg
Mount Mazama collapsed into a caldera, which was filled with water to form Crater Lake.
Highest point
Elevation8,157 ft (2,486 m) [1]
Prominence382 feet (116 m)
Parent peakMount Scott
ListingOregon Highest Peaks 76th
Coordinates42°54′59″N 122°05′04″W / 42°54′59″N 122°05′04″W / 42.9165186; -122.0844711[2]
Mount Mazama is located in Oregon
Mount Mazama
Mount Mazama
Parent rangeCascade Range[1]
Topo mapUSGS Crater Lake East
Mountain typeCaldera[1]
Volcanic arcCascade Volcanic Arc
Last eruption2850 BCE[1]
Easiest routeDrive

Mount Mazama (Giiwas in the Native American language Klamath) is a complex volcano in the Oregon segment of the Cascade Volcanic Arc and the Cascade Range, in the United States. Located in Klamath County, the volcano resides 60 miles (97 km) to the north of the border between Oregon and California in the southern Cascades. The volcano's collapsed caldera holds Crater Lake, and the entire mountain is located within Crater Lake National Park. Mazama has an elevation of 8,157 feet (2,486 m), and Crater Lake reaches a depth of 1,943 feet (592 m), making it the deepest freshwater body in the United States and the second deepest in North America after Great Slave Lake in Canada.

Mazama formed as a group of overlapping volcanic edifices such as shield volcanoes and small composite cones, becoming active intermittently until its climactic eruption. Mazama's caldera was created by this enormous eruption about 7,700 years ago, the largest within the Cascade Volcanic Arc in a million years. The eruption also destroyed Mazama's summit, reducing Mazama's approximate 12,000-foot (3,700 m) height by about 1 mile (1,600 m). Much of the volcano fell into the volcano's partially emptied neck and magma chamber. The region is actively undergoing extension of tectonic plates, and it features numerous volcanic landforms and faults. Though Mazama is currently dormant, the United States Geological Survey thinks that future eruptions are likely, though on a smaller scale than the climactic eruption. Still, Mazama poses a threat to the nearby surroundings if it resumes activity.

Indigenous populations have inhabited the area around Mazama and Crater Lake for at least 10,000 years, and the volcano plays an important role in local folklore. Caucasian settlers first reached the region in the mid-19th century. Since the late 1800s, the area has been extensively studied by scientists for its geological phenomena and more recently for its potential sources of geothermal energy. Crater Lake and Mazama's remnants sustain diverse ecosystems, which are closely monitored by the National Park Service because of their remoteness and ecological importance. Recreational activities including hiking, biking, snowshoeing, fishing, and cross-country skiing are available, and during the summer, campgrounds and lodges at Crater Lake are open to visitors.


Mount Mazama lies in Klamath County, within the U.S. state of Oregon,[2] 60 miles (97 km) north of the border between Oregon and California. It lies in the southern portion of the Cascade Range. Crater Lake sits partly inside the volcano's caldera,[3] with a depth of 1,943 feet (592 m)[a]; it thus represents the deepest body of freshwater in the United States[4][5] and the second deepest in North America after Great Slave Lake in Canada.[6] Before its caldera-forming eruption, Mazama stood at an elevation between 10,800 to 12,100 feet (3,300 to 3,700 m),[7] placing it about 1 mile (1.6 km) above the lake[4] and making it Oregon's highest peak.[8] The Global Volcanism Program currently lists its elevation at 8,157 feet (2,486 m),[1] while the Geographic Names Information System provides an elevation of 6,174 feet (1,882 m).[2]

Crater Lake National Park

Crater Lake National Park covers an area of 250 square miles (650 km2), including forest areas, alpine terrain, the Crater Lake, and the vast majority of Mount Mazama. A wilderness area, it was dedicated in 1902 and is overseen by the National Park Service. It receives about 500,000 visitors each year, and these tourists can go hiking, take bike, ranger-guided, and trolley tours, swim, fish, camp, and participate in other recreational activities. While the Park area remains open throughout the year, certain roads and facilities close in the winter season.[9]

Physical geography

Crater Lake, formed in the caldera from Mazama's collapse

Glaciers formed on the mountain over and over as Mazama developed. They carved trenches in the flanks of the volcano in addition to U-shaped valleys under the base of the volcanic cone. These can be observed at three large glacial canyons on its southern slopes: Kerr Notch, Munson Balley, and Sun Notch.[4] Whenever eruptions took place in the presence of ice, lava was chilled by glaciers, creating glassy talus deposits. Sometimes, the lava coursed into areas previously carved by glaciers like at Sentinel Rock, filling canyons with volcanic rock. Moraines occur up to 17 miles (27 km) from the rim of Mazama's caldera and there are glacial striations visible at several sites in the area.[10] When the climactic eruption occurred, the climate was warm and dry,[11] and the most recent period of glacial advance ceased about 27,000 years ago, so by the time Mazama collapsed, ice was likely only present at higher elevations.[4] Using argon geochronology and paleoclimatic records, scientists have identified that the Sand Creek, Sun Creek, and Annie Creek canyons were carved by the advance of ice over lava flows, pushing debris towards Klamath Marsh and Klamath Graben or nearby rivers.[12] A glacial cirque can be seen on Mount Scott's northwestern flank, and glacial till occurs on Mazama's slopes, especially on the western slopes and at lower elevations. Till and fluvial sediments occur in the caldera walls, forming particularly thick deposits under Roundtop and Wineglass.[12] Many lava flows that were glaciated have since been covered by more recent lava flows.

Crater Lake formed from a network of lakes and ponds, eventually reaching a depth of 1,949 feet (594 m). Lake levels rose while the Wizard Island landform inside the crater was forming. Water interacted with lava flows to form pillow lava.[13] Because of climate change patterns over time, Crater Lake's surface level has changed, dropping as much as 40 feet (12 m) for example at the beginning of the 1900s.[14] Now the water from precipitation nearly equals water lost to evaporation and drainage, with most leakage taking place at the Wineglass deposit at the northern side of the crater, without which the lake would likely have overflowed at the northern side.[6]

Average snowfall in the Crater Lake area has been decreasing since the 1930s. Crater Lake's mean surface water temperatures have increased about 5 °F (3 °C) since the 1960s. Though this may eventually cause algae to grow and obscure the water, Crater Lake remains one of the cleanest bodies of water in the world.[15]

Other Languages
euskara: Mazama mendia
français: Mont Mazama
한국어: 마자마산
ქართული: მაზამა
Bahasa Melayu: Gunung Berapi Mazama
Nederlands: Mount Mazama
polski: Mount Mazama
srpskohrvatski / српскохрватски: Mount Mazama
Türkçe: Mazama Dağı
Tiếng Việt: Núi Mazama