Crater Lake (Klamath:Giiwas)[2] is avolcanic crater lake in south-centralOregon in theWesternUnited States. It is the main feature ofCrater Lake National Park and is a tourist attraction for its deep blue color andwater clarity. The lake partly fills a 2,148-foot-deep (655 m)caldera[3] that was formed around 7,700 (± 150) years ago[4]by the collapse of the volcanoMount Mazama. No rivers flow into or out of the lake; the evaporation is compensated for by rain and snowfall at a rate such that the total amount of water is replaced every 150 years.[5] With a depth of 1,949 feet (594 m),[6] the lake is thedeepest in the United States. In the world, it ranks eleventh for maximum depth, as well as fifth for mean depth.
Crater Lake features two small islands.Wizard Island, located near the western shore of the lake, is acinder cone about 316 acres (128 hectares) in size.Phantom Ship, a natural rock pillar, is located near the southern shore.
Since 2002, one of Oregon's regular-issuelicense-plate design has featured Crater Lake[7] and a one-time plate surcharge is used to support the operation of Crater Lake National Park.[8] The commemorative OregonState Quarter, which was released by theUnited States Mint in 2005, features animage of Crater Lake on its reverse.[9]
The lake and surrounding park areas offer many recreational activities, including hiking, biking, snowshoeing, fishing, and cross-country skiing, and during the summer, campgrounds and lodges at Crater Lake are open to visitors.
Crater Lake is inKlamath County, around 60 miles (97 km) northwest of the county seat ofKlamath Falls, and about 80 miles (130 km) northeast of the city ofMedford.[10]
A Native American connection with this area has been traced back to before the eruption of Mount Mazama. Archaeologists have found sandals and other artifacts buried under layers of ash, dust, and pumice that antedate the eruption roughly 7,700 years ago.[11] Crater Lake remains significant to the Klamath tribes today.[12] The Klamath name for the lake isGiiwas.[11]
In June 1853, Isaac Skeeter, John Wesley Hillman, and another man were the first non-Native Americans to report sighting the lake, while on a mining trip; Skeeter named it "Deep Blue Lake," inspired by Hillman's description of the site. The lake was renamed at least three times, as Blue Lake, Lake Majesty, and finally Crater Lake.[13][14]
The lake is 5 by 6 miles (8.0 by 9.7 km) across, with a caldera rim ranging in elevation from 7,000 to 8,000 feet (2,100 to 2,400 m) and an average lake depth of 1,148 feet (350 m). The lake's maximum depth has been measured at 1,949 feet (594 m),[3][6][15][16] which fluctuates slightly as the weather changes.[3] On the basis of maximum depth, Crater Lake is the deepest lake in the United States, the second-deepest in North America (afterGreat Slave Lake in Canada), and theeleventh-deepest lake in the world.[17] Crater Lake is often cited as the seventh-deepest lake in the world, but this ranking excludesLake Vostok in Antarctica,[18][19] which is beneath about 13,000 feet (4,000 m) of ice, and the recentdepth soundings ofO'Higgins/San Martín Lake, which is along the border ofChile andArgentina.[20]
When considering the mean, or average depth of lakes, Crater Lake becomes the deepest lake in the Western Hemisphere and the third-deepest in the world. Crater Lake Institute Director andlimnologist Owen Hoffman states that "Crater Lake is the deepest, when compared on the basis of average depth among lakes whose basins are entirely abovesea level. The average depths of LakesBaikal andTanganyika are deeper than Crater Lake; however, both have basins that extend below sea level."[19][21]
Geologic map of the lake floorCrater Lake from space
Mount Mazama, part of theCascade Rangevolcanic arc, was built up mostly ofandesite,dacite, andrhyodacite over a period of at least 400,000 years. The caldera was created in a massivevolcanic eruption between 6,000 and 8,000 years ago that led to the subsidence of Mount Mazama. About 12 cubic miles (50 km3) of rhyodacite was erupted in this event. Since that time, all eruptions on Mazama have been confined to the caldera.[22][23]
Lava eruptions later created a central platform,Wizard Island, Merriam Cone, and other, smaller volcanic features, including a rhyodacite dome that was eventually created atop the central platform. Sediments andlandslide debris also covered the caldera floor.[24]
Eventually, the caldera cooled, allowing rain and snow to accumulate and form a lake. Landslides from the caldera rim thereafter formed debris fans andturbidite sediments on the lake bed.Fumaroles andhot springs remained common and active during this period. Also after some time, the slopes of the lake's caldera rim more or less stabilized, streams restored a radial drainage pattern on the mountain, and dense forests began to revegetate the barren landscape. It is estimated that about 720 years was required to fill the lake to its present depth of 1,949 feet (594 m). Much of this occurred during a period when the prevailing climate was less moist than at present.[25]
Somehydrothermal activity remains along the lake floor, suggesting that at some time in the future, Mazama may erupt once again.[26]
Crater Lake features asubalpine climate, with the rare dry-summer type (Köppen classificationDsc) owing to its high elevation and – like all of Oregon – the strong summer influence of theNorth Pacific High. In the summer, the weather is mild and dry, but in the winter is cold and the powerful influence of theAleutian Low allows for enormous snowfalls averaging 463.1 inches (11.76 m) per year and maximum snow cover averaging 139 in or 3.53 m. This snow does not usually melt until mid-July, and allows for substantial glaciers on adjacent mountains. In the winter of 1949/1950 as much as 885.1 inches (22.48 m) of snow fell, while the less complete snow cover records show cover as high as 192 in or 4.88 m occurred during another particularly unsettled winter in 1981/1982.[27] The heaviest daily snowfall was 37.0 inches (94.0 cm), which occurred as recently as February 28, 1971; 20 in (51 cm) or more in one storm has occurred in both June and September. Hard frost is possible even into the summer, and the average window for freezing temperatures is August 20 through July 10, while for measurable (≥0.1 in or 0.25 cm) snowfall, September 28 through June 11.[28]
Climate data for Crater Lake National Park Headquarters, Oregon, 1991–2020 normals, extremes 1919–present
Since the collapse of Mount Mazama due to a volcanic eruption formed Crater Lake, no fish inhabited the lake until William Gladstone Steel decided to stock it in 1888 to allow for fishing.[31] Regular stocking continued until 1941, when it was evident that the fish could maintain a stable population without outside interference. Six species of fish were originally stocked, but only two species have survived:kokanee salmon andrainbow trout, with the former being the most plentiful.[31] Fishing in Crater Lake is promoted because the fish species are not indigenous to the lake.[32]
Crater Lake is also known for the "Old Man of the Lake", a full-sized tree which is now a log that has been bobbing vertically in the lake for over a century.[33][34] The low temperature of the water has slowed the decomposition of the wood, hence its longevity.
In 1987, scientists sent asubmersible down to the depths of Crater Lake to obtain more information about the geology at the bottom of the lake,[35] and inspect moss samples found in moss beds as deep as 600 feet (180 m).[36]
Due to several unique factors, mainly that the lake has no inlets ortributaries, the waters of Crater Lake are some of the purest in the world because of the absence of pollutants. Clarity readings from aSecchi disk have consistently been measured as being 120 ft (37 m), which is very clear for any natural body of water.[37] In 1997, scientists recorded a record clarity of 142 ft (43 m).
The lake has relatively high levels of dissolved salts, totalalkalinity, and conductivity. The averagepH has generally ranged between 7 and 8.[38]
TheKlamath tribe ofNative Americans, whose oral history describes their ancestors witnessing the collapse of Mount Mazama and the formation of Crater Lake, regard the lake as an "abode to the Great Spirit".[39] Klamath oral history tells of a battle between the sky god Skell and the god of the underworldLlao (a prominent feature at Crater Lake is Llao Rock). Mount Mazama was destroyed in the battle, creating Crater Lake, calledgiiwas in theKlamath language.[2] The Klamath people used Crater Lake invision quests, which often involved climbing the caldera walls and other dangerous tasks. Those who were successful in such quests were often regarded as having more spiritual powers. The tribe still holds Crater Lake in high regard as a spiritual site.[11][40]
Located 56 miles (90 km) north of the city ofKlamath Falls and 62 miles (100 km) northeast ofMedford, Crater Lake can be reached fromU.S. Route 97 on the east, on the southwest by Highway 62, and on the northwest by Highway 138.[41] Crater Lake and the remnants of Mount Mazama can be seen from Rim Drive, a 33-mile (53 km) road that surrounds the caldera,[42] which is the only part within the Crater Lake National Park where vehicles are permitted.[41] TheGarfield Peak Trail, which runs 1.5 miles (2.4 km) east from theCrater Lake Lodge, offers views from 1,900 feet (580 m) above the lake's surface, with Mount Shasta visible 125 miles (201 km) southward. Another trail runs for 2.5 miles (4.0 km) from Rim Drive's eastern edge to Mount Scott, which offers views of central and southern Oregon such as the Three Sisters located 80 miles (130 km) north of Mazama andMount Thielsen, also to the north. The Cleetwood trail leads for 1 mile (1.6 km) down the northern flank of the caldera rim, eventually reaching Cleetwood Cove where boat trips run from late June or early July throughout the summer season to Wizard Island. Wizard Island can be climbed, offering views of Crater Lake.[42]
Swimming is permitted in Crater Lake, but the only legal and safe way to get to the shore is by following Cleetwood Cove trail and people can enter the water from there.[12] Other activities include fishing and a 2-hour boat tour around the lake provided by a Park Ranger fromCrater Lake National Park.[43]
As the region lies within a national park area, collecting rocks within the vicinity is prohibited unless a permit is obtained.[44] The park's facilities lie at Rim Village, at the southern edge of the caldera.[41] Lodging and camping facilities open during the summer season between May and October.[45] No lodges, gas stations, or camping areas remain open from October through late May.[46] Popular activities within Crater Lake National Park includebiking,[47] fishing,[48]cross-country skiing, andsnowshoeing.[49]
^Cranson, K. R. (2005).Crater Lake, gem of the Cascades: the geological story of Crater Lake National Park, Oregon (3rd ed.). Lansing, Mich: KRC Press. p. 120.ISBN978-0-9770880-0-3.A drop of water entering Crater Lake will remain there for about 150 years, its so-called residence time. Another way to think about residence time is the average amount of time required to refill a basin with new water if it were to be empted.
^abc"Park History"(PDF). National Park Service. Archived fromthe original(PDF) on April 15, 2013. RetrievedJanuary 3, 2012.
^ab"Frequently Asked Questions".Crater Lake National Park. U.S. National Park Service.Archived from the original on March 10, 2019. RetrievedMarch 11, 2019.
^Tilden, Freeman (1968).The National Parks. New York: Alfred A. Knopf.
^Andalkar, Amar (December 18, 2003)."Crater Lake (Mount Mazama)".Skiing the Cascade Volcanoes. skimountaineer.com.Archived from the original on September 10, 2013. RetrievedJuly 8, 2013.
^Noah Tesch."9 of the World's Deepest Lakes".Encyclopaedia Britannica. Archived fromthe original on April 8, 2017. RetrievedMay 8, 2017.#9 Crater Lake (1,943 feet [592 meters]), #8 Great Slave Lake (2,015 feet [614 meters])
^Evans, C.T. (2007)."Lake Baikal". Northern Virginia Community College.Archived from the original on July 24, 2013. RetrievedJuly 8, 2013.
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Bacon, Charles R.; Lanphere, Marvin A. (2006). "Eruptive history and geochronology of Mount Mazama and the Crater Lake region, Oregon".Geological Society of America Bulletin.118 (11–12):1331–1359.Bibcode:2006GSAB..118.1331B.doi:10.1130/B25906.1.
Oregon, Moon Handbooks, Judy Jewell, W. C. McRae, (Avalon Travel, Berkeley; 2012, 9th edition)ISBN978-1-59880-885-8