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Mount McLoughlin

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Mount McLoughlin
Alwilamchaldis, Mayakax, Kesh yainatat
MtMcLoughlin.jpg
Mount McLoughlin from across Willow Lake
Highest point
Elevation9,493 ft (2,893 m)  NAVD 88
Prominence4,455 feet (1,358 m)
ListingOregon county high points
Coordinates42°26′40″N 122°18′56″W / 42.444472472°N 122.315620131°W / 42.444472472; -122.315620131Coordinates: 42°26′40″N 122°18′56″W / 42.444472472°N 122.315620131°W / 42.444472472; -122.315620131 [1]
Geography
LocationJackson County, Oregon, U.S.
Parent rangeCascade Range
Topo mapUSGS Mount McLoughlin
Geology
Age of rockLess than 700,000 years
Mountain typeStratovolcano[2]
Volcanic arcCascade Volcanic Arc
Last eruptionAbout 30,000 years ago[2]
Climbing
Easiest routeTrail hike[3]

Mount McLoughlin is a steep-sided stratovolcano, or composite volcano, in the Cascade Range of southern Oregon and within the Sky Lakes Wilderness. It is one of the volcanic peaks in the Cascade Volcanic Arc, within the High Cascades sector. A prominent landmark for the Rogue River Valley, the mountain is north of Mount Shasta, and Crater Lake lies to the north-northeast, it was named around 1838 after John McLoughlin, a Chief Factor for the Hudson's Bay Company. McLouglin's prominence has made it a landmark to Native American populations for thousands of years.

McLoughlin consists largely of basaltic andesite, it underwent three major eruptive periods before its last activity took place between 30,000 and 20,000 years ago. It is not currently monitored for activity or deformation. Diverse species of flora and fauna inhabit the area, which is subject to frequent snowfall and temperature variation between seasons; the Pacific Crest Trail skirts the eastern and northern sides and also accesses the only trail to the summit, the 6-mile (9.7 km) McLoughlin Trail 3716. The mountain can also be skied.

Geography[edit]

Location in Oregon relative to other major volcanoes

The major landmark for the Rogue River Valley,[4] Mount McLoughlin reaches an elevation of 9,493 feet (2,893 m);[1][a] the tallest volcano in between Mount Shasta — located 70 miles (110 km) to the south[5] — and South Sister 120 miles (190 km) to the north, it lies in the Cascade Range, in the southern portion of the U.S. state of Oregon.[1] Most of the volcano lies in Jackson County,[6][7] though the eastern side of its base lies in Klamath County,[4] it is the sixth tallest peak in Oregon,[8] but despite its height, Mount McLoughlin only has a volume of 3 cubic miles (13 km3).[9]

The volcano includes the North Squaw Tip and South Squaw Tip peaks, which occur on its flanks at elevations of 7,070 feet (2,150 m)[6] and 7,654 feet (2,333 m),[7] respectively, it can be seen from the Interstate 5 and U.S. Route 97 highways.[5] From the southwest and southeast, it has a symmetrical appearance, but the northeastern flank of the volcano has been eroded and transformed into a hollow amphitheater.[10]

Wilderness[edit]

Main article: Sky Lakes Wilderness

McLoughlin lies within the Sky Lakes Wilderness area,[2] part of the Rogue River–Siskiyou and the Fremont–Winema National Forests.[4] The Sky Lakes Wilderness covers an area of 113,590 acres (459.7 km2), with a width of 6 miles (9.7 km) and a length of 27 miles (43 km). Designated by the United States Congress in 1984, it stretches from Crater Lake National Park to Highway 140 at the south and ranges in elevation from 3,800 feet (1,200 m) in the Middle Fork canyon of the Rogue River to the peak of McLoughlin;[11] the wilderness area encompasses more than 200 bodies of water including ponds and lakes, in addition to forests and mountain ridges.[11]

Physical geography[edit]

The local area has warm, dry summers during the daytime with cool nights,[12] and snowy winters that impede access to the Sky Lakes Wilderness through July.[11] Moisture is limited between June and October barring occasional thunderstorms, which accounts for a very short growing season between ice thawing and drought.[11] On average, precipitation does not exceed 40 inches (100 cm) at medium elevations, reaching 80 to 90 inches (200 to 230 cm) at greater heights, most of which consists of snowfall.[12]

Around the base of the mountain, there are a number of lakes, including the Lake of the Woods and Fourmile Lake; the Upper Klamath Lake, the largest body of freshwater in the state, sits to the east of Mount McLoughlin.[5] The Summit Lake is a small lake on the northern slope of the volcano between the Rogue River and the Klamath Basin;[13] the Big Butte Creek, a tributary of the Rogue River, drains the northwestern part of McLoughlin,[14] while the Little Butte Creek is fed by the southern flanks.[15]

Ecology[edit]

About 20 tree species can be found throughout Mount McLoughlin's surroundings, including Pacific yew at low elevations, mountain hemlock, whitebark pine, and subalpine fir at higher elevations, and lodgepole pine and red fir throughout.[11] Other plant species include shrubs, wildflowers, junipers, heather, columbine, kinnikinnick, huckleberry,[11] chinquapins, grouse huckleberry, and bearberry.[12]

Common fauna in the area include chipmunks, deer, elk, American black bears, coyotes, while yellow-bellied marmots, fishers, pikas, and American martens are less common.[11] More than 150 bird species live in the Big Butte Creek watershed near McLoughlin.[16][17] Eagles and hawks can be sighted in the vicinity,[11] as can spotted owls.[12] Goshawks like to live beneath the tree canopy inn the region.[11] Amphibian species like Oregon spotted frogs and Cascades frogs live in certain parts of the watershed.[16][17] Fish species include Chinook salmon, rainbow trout, Coho salmon, Pacific lamprey,[16][17][18] and coastal cutthroat trout.[18][19]

Geology[edit]

Mount McLoughlin from the north

Little was known about Mount McLoughlin's geology until the 1970s. Much of what is known today comes from LeRoy Maynard of the Center for Volcanology at the University of Oregon, his work established that the volcano was built over three eruptive phases, each with their own eruption types.[20] James Smith from the United States Geological Survey expanded on Maynard's findings, producing a map of the McLoughlin region.[20]

McLoughlin is part of the High Cascades,[5] which trend north–south.[21] Formed towards the end of the Pleistocene Epoch, these mountains are underlain by more ancient volcanoes that subsided due to parallel north–south faulting in the surrounding region.[22] Like other Cascade volcanoes, Mount McLoughlin was fed by magma chambers produced by the subduction of the Juan de Fuca tectonic plate under the western edge of the North American tectonic plate.[23] Within Oregon, plutons, or bodies of intrusive igneous rock that crystallize from magma cooling below the surface of the Earth, lay between 47 to 68 miles (75 to 110 km) northwest of the major High Cascade axis. At McLoughlin, mean displacement rates for the past 16 million years have been 0.14 to 0.28 inches (3.5 to 7.1 mm) each year.[24]

The volcano shows magnetic high points to the east of its main cone, suggesting that it has normal magnetic polarization that corresponds to an age of less than 700,000 years.[2] Other evidence that the volcano is geologically young include its symmetrical shape on the western and southern sides, its well-preserved lava flow deposits, and the absence of soil formation on many of its flow deposits.[2]

McLoughlin is a stratovolcano,[2] made up of basaltic andesite on top of underlying basaltic andesitic shield volcanoes.[25] Much of its central volcanic cone formed within the last 200,000 years, including lava flows on the sides of the mountain that are between 30,000 and 20,000 years old;[9] the volcano has a volume of 3 cubic miles (13 km3),[9] and its lava is predominantly basaltic andesite with silicon dioxide content between 53 and 57 percent, though it also has andesite.[25]

During the last ice age, a large ice cap buried most of the High Cascades, reaching thicknesses in the thousands of feet. Pleistocene glaciers carved out McLoughlin's major volcanic cone, excavating two solidified lava tubes that reached the summit crater. From 25,000 to 12,000 years ago, glaciers on the northern slopes of the volcano combined with an ice cap at the base of the volcano that was about 500 feet (150 m) thick. A cirque glacier occupied part of the depression until early in the 20th century;[20] the volcano displays a lack of snow during the summer season.[26]

Nearby features[edit]

Pelican Butte with McLoughlin in the far left

Two nearby volcanoes closely resemble Mount McLoughlin in composition and structure. Brown Mountain, a shield volcano with a volume of 1 cubic mile (4.2 km3), lies to the southeast, while Pelican Butte, the most prominent shield volcano in the southern Cascades of Oregon, lies to the east.[27]

Brown Mountain has been dated to between 60,000 and 12,000 years old, it produced basaltic andesite lava flows that have not been heavily eroded, but during Pleistocene glacial advance, ice streams on the volcano ate away at the cinder cone that formed Brown Mountain's summit. This formed a glacial cirque with a bowl shape on the northeastern flank.[27]

Pelican Butte reaches an elevation of 8,036 feet (2,449 m), and it features gradual slopes. Adjacent to Klamath Lake, it has a greater volume than McLoughlin at 5 cubic miles (21 km3), and it is made up of basaltic andesite. Like Brown Mountain, Pelican Butte has a cinder cone on the top of its summit, in addition to a glacial cirque and ravine that were excavated on its northeastern side;[27] these eroded areas exhibit pyroclastic rock in a matrix with lava flows, suggesting that blocky and ʻaʻā lavas formed an outer shell around Pelican Butte's fragmented interior.[28] Glaciation has also lowered the overall volcano by tens of yards.[29]

Other volcanoes can be found within the Sky Lakes Wilderness area, including lava flows and mud flows at Big Bunchgrass Butte and Imagination Peak, in addition to more recent eruptive activity at Goosenest Mountain in the northeastern sector.[12]

Eruptive history[edit]

Mount McLoughlin from the Upper Klamath Lake, showing its summit cone

Mount McLoughlin underwent at least three distinct eruptive phases.[2] Early activity at Mount McLoughlin was explosive, and it yielded tephra and pyroclastic rock that built about a third of the overall volume;[25] these eruptions also yielded lava flows, but they only occurred on the lower flanks. The northwestern flank has volcanic vents that produced lava flows responsible for inundating the Fourbit Creek valley 4 miles (6.4 km) from the base of McLoughlin, which extend up to the Big Butte Springs. Other lava flows from earlier eruptions reach at least 6 miles (9.7 km) from the base of the mountain, a number of which run along the Oregon Route 140 highway. One ʻaʻā stream that filled a river valley for 6 miles (9.7 km) in length moved from an elevation of 5,000 feet (1,500 m) to 3,000 feet (910 m), though it was thin, with more than 2.5 miles (4.0 km) of its length being less than 500 feet (150 m) in width.[25]

A second eruptive stage was characterized by large lava flows, which covered the inner pyroclastic core with basaltic andesite; these thin lava flows formed a shell around the loosely compacted pyroclastic interior.[30] The third stage of development consisted of floods of blocky lava erupting from below the summit and more fluid lavas erupting from basal fissures, mostly confined to the south slope. North Squaw Tip[6] and South Squaw Tip[7] on McLoughlin's west flank now mark the site of the two major blocky flow vents. There are two smaller vents as well; the entire third stage is thought to have happened after the last Pleistocene glaciers in the area had melted, due to a general lack of weathering and fresh appearance of the solidified lava. The freshest lava flows at Mount McLoughlin occur on the southern and western flanks of the mountain, and they are thought to be between 30,000 and 20,000 years old.[27]

Future activity[edit]

Mount McLoughlin's main volcanic cone has not erupted during the Holocene,[31] with the last production of lava flows taking place between 30,000 and 20,000 years ago;[32] the volcano is not currently monitored for activity[33] or deformation.[31] The closest seismic monitoring stations lie 62 miles (100 km) to the south near Mount Shasta and the Medicine Lake Volcano.[34]

Human history[edit]

Mount McLoughlin got its official name from John McLoughlin (pictured), a factor for the Hudson's Bay Company

McLouglin has served as a landmark to Native American populations for thousands of years, they utilized the area to hunt and gather berries.[11] The Takelma people referred to it as "Mal-sr" or "Alwilamchaldis", one of their mythical heroes, and they considered it the home of Tasuune, or the "Acorn Woman", a being that helped their acorns grow every year.[35] In the culture of the Shasta people, McLoughlin was known as "Makayax"; the Klamath people named the volcano "Walum" and "Kesh yainatat", meaning the home of the "dwarf old woman" that controlled the west wind. McLoughlin was called "Melaiksi" by the Modoc people;[35] the Little Butte Creek which drains from McLoughlin was called "So-ytanak", translating as "corner" or "rock house", by the Upper Takelma people.[15]

First detected by Peter Skene Ogden in 1827, McLoughlin has a complex name-place history.[36] Ogden called the volcano "Mt. Sastise" after the Shasta Native Americans that helped him reach the Rogue Valley, but this name was later exchanged with Mount Shasta in northern California, then called "Pit Mountain".[36] To local residents, Mount McLoughlin's English name was Mount Pitt,[36] though it came to be referred to by other names including Mt. John Quincy Adams, Mt. Clear View, Snowy Butte,[36] and Mt. Madison,[37] also appearing in maps as Mount Pitt, Mount Simpson, and Mount Jackson.[2] Though the volcano was also known as Mount McLoughlin during the 1800s, it was officially renamed in 1905 by the Oregon Legislative Assembly[38] after Dr. John McLoughlin, a factor for the Hudson's Bay Company noted for helping American settlers in the 1830s and 1840s.[5] An important figure in the local fur trade, McLoughlin was also known as the "Father of Oregon";[38] the change from Pitt to McLoughlin was later confirmed by the United States Board on Geographic Names in 1912.[39]

The area around Mount McLoughlin was frequented by fur trappers and explorers, but they did not settle for long stays in the area.[2] Settlers living near the surrounding Sky Lakes Wilderness trapped beavers and martens during the winter seasons, hunted, and grazed sheep in warmer months. Stuart Falls and Twin Ponds marked popular spots for picking huckleberries. Trails and fire lookouts were constructed for the Sky Lakes Wilderness area in the early 1900s, with the Pacific Crest Trail expanding into the region during the mid-1970s, superseding the pre-existing Oregon Skyline Trail.[11]

Mount McLoughlin's first known ascent took place in 1858, when Joseph Burpee, William Wilkinson, Dr. Greer, Henry Klippel, John S. Love, and Robert Haines, from the city of Jacksonville, reached the summit from the northeast; the event was reported in a letter published by the Jacksonville Democratic Times on May 28, 1897.[36] In 1896, members of the Mazama mountaineering club including Lottie Reed, Henry Pittock, and Leslie Scott ascended the mountain.[4]

As of 1926, Mount McLoughlin's western flank acts as the municipal watershed for Medford, its melted snow feeding the Big Butte Springs near the city; the summer melting of snow forms a shape that is referred to locally as "the angel wings" or "the diving eagle", which local fishers consider a sign of peak fishing opportunities in the mountain's lakes.[4]

Recreation[edit]

Mount McLoughlin has a 6-mile (9.7 km) trail to its summit, which can be climbed without great technical prowess.[29] It gains more than 4,000 feet (1,200 m) in elevation, typically requiring four and five hours from start to finish;[12] the trail receives moderate to heavy use each year;[2] the peak is easiest to reach after July, when snow is minimal along the path. The route's trailhead, known as McLoughlin Trail 3716, can be reached from milepost 31 on Oregon Route 140, 2.5 miles (4.0 km) down an unpaved road. Beginning with about 1 mile (1.6 km) of the Pacific Crest Trail,[2] it traverses through a forested area after passing through open meadows and a stream, running for 4.5 miles (7.2 km) before reaching timber line. The last 1.5 miles (2.4 km) of the path travel over blocky lava and rubble, and above the tree line, the trail is less clearly delineated. From the summit, Mount Shasta and Crater Lake can be seen;[29] the trail can also be accessed on horseback, and dogs on leashes are also permitted. Forest passes must be purchased for access.[40]

During the winter, the climb requires snowshoes, crampons, and ice axes, and is far more challenging than the popular summertime route;[41] the mountain can also be skied, which has become more popular in recent years.[42]

Pelican Butte can also be climbed, and is a less demanding ascent;[29] the trail lasts about 5 hours and covers 6 miles (9.7 km).[43] As a result of its lower elevation, it has less snow cover, but it is still popular among skiers and snowboarders.[43]

See also[edit]

Notes[edit]

  • [a] ^ Other sources list the elevation as 9,496 feet (2,894 m).[5]

References[edit]

  1. ^ a b c "Mount McLoughlin LOH". NGS data sheet. U.S. National Geodetic Survey. Retrieved 2008-11-16.
  2. ^ a b c d e f g h i j k "Description: Mount McLoughlin Volcano, Oregon". Cascades Volcano Observatory, U.S. National Geodetic Survey. Archived from the original on 2012-10-06. Retrieved 2013-01-02.
  3. ^ "Mount McLoughlin Trail, #3716". Rogue River–Siskiyou National Forest, United States Forest Service. Retrieved 2013-01-02.
  4. ^ a b c d e LaLande, J. (September 14, 2017). "Mount McLoughlin". The Oregon Encyclopedia. Oregon Historical Society. Retrieved January 29, 2018.
  5. ^ a b c d e f Harris 2005, p. 127.
  6. ^ a b c "North Squaw Tip". Geographic Names Information System. United States Geological Survey. Retrieved January 26, 2018.
  7. ^ a b c "South Squaw Tip". Geographic Names Information System. United States Geological Survey. Retrieved January 26, 2018.
  8. ^ Smoot 2012, p. 205.
  9. ^ a b c "McLoughlin". Volcano World. Oregon State University. 2018. Retrieved January 26, 2018.
  10. ^ Harris 2005, pp. 127–128.
  11. ^ a b c d e f g h i j k "Rogue River National Forest: Sky Lakes Wilderness". United States Forest Service. January 15, 2010. Archived from the original on January 15, 2010. Retrieved January 27, 2018.CS1 maint: BOT: original-url status unknown (link)
  12. ^ a b c d e f Wuerthner 2003, p. 166.
  13. ^ LaLande 1995, p. 58.
  14. ^ LaLande 1995, p. 10.
  15. ^ a b LaLande 1995, p. 38.
  16. ^ a b c BLM 1999.
  17. ^ a b c BLM Central Watershed Analysis.
  18. ^ a b BLM 2008.
  19. ^ Rogue River National Forest 1995.
  20. ^ a b c Harris 2005, p. 128.
  21. ^ Joslin 2005, p. 30.
  22. ^ Joslin 2005, p. 31.
  23. ^ Wells & McCaffrey 2013, p. 1027.
  24. ^ Wells & McCaffrey 2013, p. 1028.
  25. ^ a b c d Harris 2005, p. 129.
  26. ^ Richard, T. (June 9, 2008). "Mount McLoughlin: the peak of southern Oregon". OregonLive.com. Advance Publications. Retrieved January 29, 2018.
  27. ^ a b c d Harris 2005, p. 131.
  28. ^ Harris 2005, pp. 131–132.
  29. ^ a b c d Harris 2005, p. 132.
  30. ^ Harris 2005, p. 130.
  31. ^ a b Norris 1991, p. 66.
  32. ^ "McLoughlin". Global Volcanism Program. Smithsonian Institution. Retrieved January 28, 2018.
  33. ^ Norris 1991, p. 1.
  34. ^ Norris 1991, pp. 66–67.
  35. ^ a b LaLande 1995, p. 41.
  36. ^ a b c d e LaLande 1995, p. 42.
  37. ^ "Nomenclature of Northwest Mountains". United States Geological Survey. January 5, 2016. Retrieved January 27, 2018.
  38. ^ a b "Cascade Range Volcanoes Volcano Names". United States Geological Survey. January 5, 2016. Retrieved January 27, 2018.
  39. ^ "Cascade Range Volcanoes: Historical Timeline". United States Geological Survey. January 5, 2016. Retrieved January 27, 2018.
  40. ^ Dunegan 2013, p. 145.
  41. ^ Urness, Z. (January 11, 2016). "Mount McLoughlin: Winter climb to Rogue Valley's rooftop". Statesman Journal. Gannett Company. Retrieved January 29, 2018.
  42. ^ Freeman, M. (January 27, 2017). "Skiing from the summit of Mount McLoughlin". Mail Tribune. Rosebud Media LLC. Retrieved January 29, 2018.
  43. ^ a b Van Tilburg 2001, p. 148.

Sources[edit]

External links[edit]

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