Mount Thielsen
Mount Thielsen | |
---|---|
Highest point | |
Elevation | 9,184 ft (2,799 m) NAVD 88[1] |
Prominence | 3,342 ft (1,019 m)[2] |
Listing | Oregon county high points |
Coordinates | 43°09′10″N 122°03′59″W / 43.152837292°N 122.066514283°W[1] |
Geography | |
Location |
|
Parent range | Cascades |
Topo map | USGS Mount Thielsen |
Geology | |
Age of rock | About 290,000 years |
Mountain type | Shield volcano |
Volcanic arc | Cascade Volcanic Arc |
Climbing | |
First ascent | 1883[3] | by E.E. Hayden
Easiest route | Scramble |
Mount Thielsen, or Big Cowhorn (Klamath: hisc’akwaleeʔas),[4] is an extinct shield volcano in the Oregon High Cascades, near Mount Bailey. Because eruptive activity ceased 250,000 years ago, glaciers have heavily eroded the volcano's structure, creating precipitous slopes and a horn-like peak. The spire-like shape of Thielsen attracts lightning strikes and creates fulgurite, an unusual mineral. The prominent horn forms a centerpiece for the Mount Thielsen Wilderness, a reserve for recreational activities such as skiing and hiking. Thielson is one of Oregon's Matterhorns.
Thielsen was produced by
The area surrounding the volcano was originally inhabited by Klamath Native Americans, and was later encountered by settlers. One of the visitors was Jon Hurlburt, an early explorer of the area who named the volcano after the engineer Hans Thielsen. Later explorers discovered nearby Crater Lake. The volcano was not analyzed until 1884, when a team from the United States Geological Survey sampled its fulgurite deposits.
History
The area was originally inhabited by
In 1884 a United States Geological Survey team headed by J. S. Diller began studying the mountains of the Cascade Range. Their intended destinations included Thielsen, which was climbed and sampled for its fulgurite variant. Thielsen's spire-like top is hit by lightning so frequently that some rocks on the summit have melted into a rare mineraloid known as lechatelierite, a variety of fulgurite. The mountain has earned the nickname "the lightning rod of the Cascades".[6][10]
Apart from study, Thielsen and the rest of the Crater Lake area features heavily into 19th- and early 20th century exploration. In 1853, miners from
Geography
Regional
The
Local
Diamond Lake, formed by one of Thielsen's eruptions,[12] lies to the west of Mount Thielsen and beyond lies Mount Bailey, a much less eroded and younger stratovolcano. Thielsen's sharp peak is a prominent feature of the skyline visible from Crater Lake National Park. All three volcanoes are part of the Oregon High Cascades, a range that sections off the stratovolcanoes of Oregon that are younger than 3.5 million years. The High Cascades include Mount Jefferson, the Three Sisters, Broken Top, and other stratovolcanoes and remnants.[13]
Rock in the area ages from the
Geology
Thielsen has been so deeply eroded by glaciers that there is no summit crater and the upper part of the mountain is more or less a horn. Thielsen is a relatively old Cascade volcano, and cone-building eruptions stopped relatively early. Erosion caused during the last two or three ice ages remains visible.[14] Subsidence of the last material in Thielsen's crater moved its youngest lava more than 1,000 feet (305 m) above the active crater.[15]
On the mountain past lava flows are diverse, some as thick as 33 feet (10 m), others as thin as 1 foot (30 cm). Stack-like figures composed of
Other notable formations in the vicinity include Howlock Mountain, Windigo Butte, and Tolo Mountain. Other than Crater Lake, little water flows on the surface, but small streams have formed in canyons excavated by glaciers.
Composition
The volcanic cone of Mount Thielsen sits atop prior shield volcanoes, and has a volume of 2 cubic miles (8.3 km3). The cone was built from
Glaciation
Glaciers were present on the volcano until the conclusion of the Little Ice Age, at the beginning of the 20th century.[13] Pleistocene glaciers have largely eroded Thielsen's caldera, exposing its contents.[14] The last glacier on the mountain, the small Lathrop Glacier located in the northern cirque, melted at some point after 2016.[18] Whilst the glaciation was previously extensive, volcanic ash from eruptive activity at Mount Mazama has almost certainly masked contents.[6]
Fulgurites
Ecology
A grove of enormous
The lower slopes of Mount Thielsen are heavily forested, with low diversity of plant species.
Recreation
Mount Thielsen lies in the southern section of the Mount Thielsen Wilderness, which is part of the Deschutes, Umpqua and Fremont–Winema national forests. On the west, the wilderness borders the Oregon Cascades Recreation Area, a 157,000-square-mile (406,628 km2) area set aside by Congress in 1984.[23][24][25] The wilderness and forests offer several activities related to the mountain, such as hiking and skiing. The wilderness covers 55,100 acres (86.1 sq mi) around the volcano, featuring lakes and alpine parks.[26] It also contains 26 miles (42 km) of the Pacific Crest National Scenic Trail, accessible from a trailhead along Oregon Highway 138.[27] In 2009 the trail was selected as Oregon's best hike.[28] Three skiing trails exist on the mountain, all of black diamond rating. They follow several trails through the wilderness from the bowl of the mountain.[3]
References
- ^ a b "Mt Thielsen". NGS Data Sheet. National Geodetic Survey, National Oceanic and Atmospheric Administration, United States Department of Commerce. Retrieved November 17, 2008.
- ^ a b "Mount Thielsen, Oregon". Peakbagger.com. Retrieved April 2, 2008.
- ^ a b Andalkar, Amar (January 15, 2003). "Mount Thielsen". SkiMountaineer.com. Archived from the original on March 16, 2009. Retrieved March 29, 2009.
- ^ "Klamath Tribes Language Project". The Klamath Tribes. 2012. Archived from the original on August 20, 2013. Retrieved March 21, 2016.
- ^ a b c Topinka, Lyn (December 15, 2004). "Cascade Range Volcanoes and Volcanics". Description. United States Geological Survey. Archived from the original on September 3, 2013.
- ^ a b c d Topinka, Lyn (May 28, 2002). "Description: Mount Thielsen Volcano, Oregon". United States Geological Survey. Archived from the original on September 4, 2013.
- ^ "Klamath Tribes Language Project: Vocabulary". The Klamath Tribes. Archived from the original on May 11, 2015. Retrieved December 23, 2014.
- ISBN 9780-875951140.
- ^ Heer and Heer, p. 47.
- ^ a b c Purdom, William B. (December 1966). "Fulgurites from Mount Thielsen, Oregon" (PDF). The Ore-Bin. 28 (9). Oregon Department of Geology and Mineral Industries. Archived (PDF) from the original on September 7, 2006. Retrieved April 1, 2008.
- ^ Topinka, Lyn (April 18, 2008). "Description: Mount Mazama Volcano and Crater Lake Caldera, Oregon". United States Geological Survey. Archived from the original on October 2, 2013.
- ^ a b Molhlenbrock.[full citation needed]
- ^ ISBN 0-607-96719-6. Archived(PDF) from the original on December 23, 2014. Retrieved December 23, 2014.
- ^ a b c d e f g h i Harris, pp. 157–165.
- ^ Diller & Patton, p. 21.
- ^ a b Bishop and Allen, p. 121.
- ^ Clarke, p. 166.
- ^ "Observers: Oregon's southernmost glacier has disappeared". Herald Review. 2021. Retrieved 5 January 2021.
- ^ "Fish & Wildlife". United States Forest Service. Archived from the original on December 24, 2014. Retrieved December 23, 2014.
- ISBN 978-1-56579-434-4.
- ^ "Mount Thielsen Wilderness". Wilderness.net. Archived from the original on March 3, 2016. Retrieved April 2, 2009.
- ^ Murray, Michael (2005). Our Threatened Timberlines: The Plight of Whitebark Pine Ecosystem (Report). Vol. 12. Whitebark Pine Ecosystem Foundation.
- ^ Mount Thielsen Quadrangle, Oregon (PDF) (Map). 1 : 24,000. 7.5 Minute Series (Topographic). United States Forest Service. March 19, 2012. Archived (PDF) from the original on October 24, 2015. Retrieved December 23, 2014.
- ^ "Mount Thielsen Wilderness: Deschutes". United States Forest Service. Archived from the original on September 15, 2015. Retrieved December 23, 2014.
- ^ Schifrin, Ben (2007). Pacific Crest Trail: Oregon & Washington (PDF) (7th ed.). Berkeley, California: Wilderness Press. p. 18. Archived (PDF) from the original on March 4, 2016. Retrieved December 23, 2014.
- ^ Grubbs, p. 187.
- ^ "Mount Thielsen Wilderness: Fremont-Winema". United States Forest Service. Archived from the original on September 24, 2015. Retrieved December 23, 2014.
- ^ "Readers' Choice Awards 2009". Backpacker. 3: 53–59. January 2009.
Bibliography
- Clarke, Frank Wigglesworth (1910). Analysis of rocks and minerals from the laboratory of the United States Geological survey, 1880 to 1908. United States Geological Survey.
- Diller, Joseph Silas; Patton, Horace Bushnell (1902). The Geology and Petrography of Crater Lake National Park. United States Geological Survey.
- Grubbs, Bruce (1999). Hiking Oregon's Central Cascades. Globe Pequot.
- Harris, Stephen L. (1988). Fire Mountains of the West: The Cascade and Mono Lake Volcanoes. Missoula: Mountain Press Publishing Company. ISBN 0-87842-220-X.
- Heer, F.J.; Heer, W.F. (1914). "Hunter-Trader-Trapper". 28.
{{cite journal}}
: Cite journal requires|journal=
(help) - Mohlenbrock, Robert H. (2006). This Land: A guide to western national forests. University of California Press.
- "Mount Thielsen". Geographic Names Information System. United States Geological Survey, United States Department of the Interior. Retrieved November 17, 2008.
- "Thielsen". Global Volcanism Program. Smithsonian Institution. Retrieved 2021-06-28.