Slesse Mountain, usually referred to as Mount Slesse, is a

mountain A mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited Summit (topography), summit area, and ...

just north of the US-

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...

border, in the

Cascade Mountains The Cascade Range or Cascades is a major mountain range of western North America, extending from southern British Columbia through Washington and Oregon to Northern California. It includes both non-volcanic mountains, such as the North Cascades, ...

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...

, near the town of

Chilliwack Chilliwack ( )( hur, Ts'elxwéyeqw) is a city in the province of British Columbia, Canada. Chilliwack is surrounded by mountains and home to recreational areas such as Cultus Lake and Chilliwack Lake Provincial Parks. There are numerous outdoor ...

. It is notable for its large, steep local relief. For example, its west face drops over to Slesse Creek in less than . It is also famous for its huge Northeast Buttress; see the climbing notes below. The name means "fang" in the

Halkomelem Halkomelem (; in the Upriver dialect, in the Island dialect, and in the Downriver dialect) is a language of various First Nations peoples of the British Columbia Coast. It is spoken in what is now British Columbia, ranging from southeastern ...

language. Notable nearby mountains include

Mount Rexford Mount Rexford is a prominent mountain summit located in the Cascade Mountains of southwestern British Columbia, Canada. It is situated north of the Canada–United States border, west of Chilliwack Lake, and east of Slesse Mountain, which is ...

and

Canadian Border Peak Canadian Border Peak, , originally known simply as Border Peak, is a mountain at the head of Tamihi Creek in the North Cascades, Cascade Mountains of the Lower Mainland of British Columbia, Canada. As its name suggests, it is near the Canada–U ...

in British Columbia, and American Border Peak,

Mount Shuksan Mount Shuksan is a glaciated massif in the North Cascades National Park. Shuksan rises in Whatcom County, Washington immediately to the east of Mount Baker, and south of the Canada–US border. The mountain's name ''Shuksan'' is derived from th ...

, and

Mount Baker Mount Baker (Lummi: '; nok, Kw’eq Smaenit or '), also known as Koma Kulshan or simply Kulshan, is a active glacier-covered andesitic stratovolcano in the Cascade Volcanic Arc and the North Cascades of Washington in the United States. Mount ...

, all in the US state of

Washington Washington commonly refers to: * Washington (state), United States * Washington, D.C., the capital of the United States ** A metonym for the federal government of the United States ** Washington metropolitan area, the metropolitan area centered o ...

Geology

Most of Mount Slesse is made up of granitic rocks related to the

Chilliwack batholith The Chilliwack Batholith is a large batholith that forms much of the North Cascades in southwestern British Columbia, Canada and the U.S. state of Washington. The geological structure is named after the Chilliwack River Valley, where it outcrops ...

, which intruded the region 26 to 29 million years ago after the major

orogenic Orogeny is a mountain building process. An orogeny is an event that takes place at a convergent boundary, convergent plate margin when plate motion compresses the margin. An ''orogenic belt'' or ''orogen'' develops as the compressed plate crumpl ...

episodes in the region. This is part of the

Pemberton Volcanic Belt The Pemberton Volcanic Belt is an eroded Oligocene-Miocene volcanic belt at a low angle near the Mount Meager massif, British Columbia, Canada. The Garibaldi and Pemberton volcanic belts appear to merge into a single belt, although the Pemberton ...

, an eroded

volcanic belt A volcanic belt is a large volcanically active region. Other terms are used for smaller areas of activity, such as volcanic fields. Volcanic belts are found above zones of unusually high temperature () where magma is created by partial melting ...

that formed as a result of

subduction Subduction is a geological process in which the oceanic lithosphere is recycled into the Earth's mantle at convergent boundaries. Where the oceanic lithosphere of a tectonic plate converges with the less dense lithosphere of a second plate, the ...

of the

Farallon Plate The Farallon Plate was an ancient oceanic plate. It formed one of the three main plates of Panthalassa, alongside the Phoenix Plate and Izanagi Plate, which were connected by a triple junction. The Farallon Plate began subducting under the west c ...

starting 29 million years ago. The primary rock comprising Slesse is grey diorite from the batholith. However the summit ridge and the west face are composed of Darrington

Phyllite Phyllite ( ) is a type of foliated metamorphic rock created from slate that is further metamorphosed so that very fine grained white mica achieves a preferred orientation.Stephen Marshak ''Essentials of Geology'', 3rd ed. It is primarily compo ...

, a

metamorphic rock Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock (protolith) is subjected to temperatures greater than and, often, elevated pressure of or more, causin ...

, produced by

contact metamorphism Metamorphism is the transformation of existing rock (the protolith) to rock with a different mineral composition or texture. Metamorphism takes place at temperatures in excess of , and often also at elevated pressure or in the presence of chem ...

with the rock of the batholith and with an intrusion of

granodiorite Granodiorite () is a coarse-grained (phaneritic) intrusive igneous rock similar to granite, but containing more plagioclase feldspar than orthoclase feldspar. The term banatite is sometimes used informally for various rocks ranging from gra ...

History

Mount Slesse was first climbed on August 10, 1927, by Stan Henderson, Mills Winram, and Fred Parkes, via a route starting from Slesse Creek. The standard route today is the Southwest Route, which involves approximately of ascent, a good deal of

scrambling Scrambling is a mountaineering term for ascending steep terrain using one's hands to assist in holds and balance.''New Oxford American Dictionary''. It is also used to describe terrain that falls between hiking and rock climbing (as a “scramb ...

and some sections of technical

rock climbing Rock climbing is a sport in which participants climb up, across, or down natural rock formations. The goal is to reach the summit of a formation or the endpoint of a usually pre-defined route without falling. Rock climbing is a physically and ...

up to class 5.6. However Slesse is most famous for the Northeast Buttress, first climbed on August 28, 1963 by

Fred Beckey Friedrich Wolfgang Beckey (14 January 1923 – 30 October 2017), known as Fred Beckey, was an American rock climber, mountaineer and book author, who in seven decades of climbing achieved hundreds of first ascents of the tallest peaks and best ro ...

, Steve Marts, and Eric Bjornstad. It is a serious multi-day rock climb (

Grade V Grade most commonly refers to: * Grade (education), a measurement of a student's performance * Grade, the number of the year a student has reached in a given educational stage * Grade (slope), the steepness of a slope Grade or grading may also ref ...

) with technical difficulty of class 5.8 or 5.9. This climb is featured in Roper and Steck's ''

Fifty Classic Climbs of North America ''Fifty Classic Climbs of North America'' is a climbing guidebook and history written by Steve Roper and Allen Steck. It is considered a classic piece of climbing literature, known to many climbers as simply "The Book", and has served as an inspi ...

''. In July 1966 Hans Baer and Jack Bryan did the second ascent of this route, with one bivouac and a straightline exit at the top of the buttress. Climbers come to the

Fraser Valley The Fraser Valley is a geographical region in southwestern British Columbia, Canada and northwestern Washington State. It starts just west of Hope in a narrow valley encompassing the Fraser River and ends at the Pacific Ocean stretching from the ...

from around the world to climb the aesthetic 24 pitch granite spire, making it one of the most iconic climbs in

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

. While the original ascents of Mt. Slesse were multi-day

excursions An excursion is a trip by a group of people, usually made for leisure, education, or Physical exercise, physical purposes. It is often an adjunct to a longer journey or visit to a place, sometimes for other (typically work-related) purposes. Pu ...

, most modern climbing parties climb the route in a single day. On December 9, 1956,

Trans-Canada Air Lines Flight 810 Trans-Canada Air Lines Flight 810-9 was a Canadair North Star on a scheduled flight from Vancouver to Calgary (continuing to Regina, Winnipeg, and Toronto). The plane crashed into Mount Slesse near Chilliwack, British Columbia, Canada, on ...

, a

North Star Polaris is a star in the northern circumpolar constellation of Ursa Minor. It is designated α Ursae Minoris ( Latinized to ''Alpha Ursae Minoris'') and is commonly called the North Star or Pole Star. With an apparent magnitude that ...

airplane crashed on the upper slopes of the mountain, killing all 62 people aboard.O'Keefe, Betty and MacDonald, Ian, ''Disaster on Mount Slesse'', Caitlin Press, 2006, This was one of the world's worst

air disaster An aviation accident is defined by the Convention on International Civil Aviation Annex 13 as an occurrence associated with the operation of an aircraft, which takes place from the time any person boards the aircraft with the ''intention of fl ...

s up to that time. Prominent among the dead were team members of the

Winnipeg Blue Bombers The Winnipeg Blue Bombers are a professional Canadian football team based in Winnipeg, Manitoba. The Blue Bombers compete in the Canadian Football League (CFL) as a member club of the league's West division. They play their home games at IG Fiel ...

and

Saskatchewan Roughriders The Saskatchewan Roughriders are a professional Canadian football team based in Regina, Saskatchewan. The Roughriders compete in the Canadian Football League (CFL) as a member club of the league's West Division. The Roughriders were founded in 1 ...

, on their way home from the annual East-West All-Star Game in

Vancouver Vancouver ( ) is a major city in western Canada, located in the Lower Mainland region of British Columbia. As the List of cities in British Columbia, most populous city in the province, the 2021 Canadian census recorded 662,248 people in the ...

. A memorial to the dead can be found on a spur road just above the Chilliwack River Road. The site itself was supposed to have been consecrated by the Cemeteries Act after the discovery of the crash site and associated human remains, some of which were gathered into a common grave. Others found by climbers and hikers have been placed in a "shrine" out of the weather in a discreet location. In the 1990s the provincial government, under pressure from the Families of Slesse organization, finally passed legislation to enshrine protection of the site, which was under threat from clearcut logging at the time, and markers have been placed on trails leading into the site requesting it be respected by hikers and others accessing it.

References

External links

* * * {{cite summitpost, id=151101, title=Slesse Mountain
Trip report by George Bell

Mountains of the Lower Mainland Canadian Cascades Pemberton Volcanic Belt Igneous intrusions Paleogene magmatism Two-thousanders of British Columbia Yale Division Yale Land District

Geology

History

See also

References

Further reading

External links