Twisp Mountain is a 7,161-foot-elevation (2,183 meter) summit located in the Methow Mountains, a subset of the North Cascades in

Washington state Washington (), officially the State of Washington, is a state in the Pacific Northwest region of the Western United States. Named for George Washington—the first U.S. president—the state was formed from the western part of the Washington ...

. It is situated on the shared boundary of

North Cascades National Park North Cascades National Park is an American national park in the state of Washington. At more than , it is the largest of the three National Park Service units that comprise the North Cascades National Park Complex. North Cascades National Par ...

with

Lake Chelan-Sawtooth Wilderness The Lake Chelan-Sawtooth Wilderness is a protected wilderness area located within the Okanogan and Wenatchee national forests in Washington State. The wilderness borders Lake Chelan National Recreation Area and North Cascades National Park and ...

, as well as the common border between Chelan County and Okanogan County. Additionally, it rises immediately southwest of Twisp Pass, and one mile northeast of

Hock Mountain Hock Mountain is a 7,750-foot-elevation (2,362 meter) summit located in the Methow Mountains, a subset of the North Cascades in Washington state. It is situated on the triple-shared boundary of North Cascades National Park, Lake Chelan-Sawto ...

, the nearest higher neighbor. Precipitation

runoff Runoff, run-off or RUNOFF may refer to: * RUNOFF, the first computer text-formatting program * Runoff or run-off, another name for bleed, printing that lies beyond the edges to which a printed sheet is trimmed * Runoff or run-off, a stock market ...

from the west side of Twisp Mountain drains to the

Stehekin River The Stehekin River is a river located in Washington state in the Pacific Northwest of the United States. It is the main river flowing into Lake Chelan. Miners arrived in Stehekin River Valley in the late 19th century. They were followed by homes ...

via Bridge Creek, whereas the east side of the mountain drains into the South Fork Twisp River.

Climate

Most weather fronts originate in the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

, and travel east toward the Cascade Mountains. As fronts approach the North Cascades, they are forced upward by the peaks of the Cascade Range, causing them to drop their moisture in the form of

rain Rain is water droplets that have condensed from atmospheric water vapor and then fall under gravity. Rain is a major component of the water cycle and is responsible for depositing most of the fresh water on the Earth. It provides water f ...

snowfall Snow comprises individual ice crystals that grow while suspended in the atmosphere—usually within clouds—and then fall, accumulating on the ground where they undergo further changes. It consists of frozen crystalline water throughout ...

onto the Cascades. As a result, the west side of the North Cascades experiences high precipitation, especially during the winter months in the form of snowfall. During winter months, weather is usually cloudy, but, due to high pressure systems over the Pacific Ocean that intensify during summer months, there is often little or no cloud cover during the summer.Beckey, Fred W. Cascade Alpine Guide, Climbing and High Routes. Seattle, WA: Mountaineers Books, 2008. Because of maritime influence, snow tends to be wet and heavy, resulting in

avalanche An avalanche is a rapid flow of snow down a slope, such as a hill or mountain. Avalanches can be set off spontaneously, by such factors as increased precipitation or snowpack weakening, or by external means such as humans, animals, and earth ...

danger.

Etymology

In addition to Twisp Mountain, the Twisp name is applied to Twisp River, Twisp Pass, and the community of

Twisp Twisp is a town in Okanogan County in north central Washington, which sits at the confluence of the Twisp and Methow rivers. The population was 938 at the time of the 2000 census and decreased to 919 at the time of the 2010 census. History On ...

. The common explanation is that Twisp comes from the Okanagan placename ''/txʷəc'p/'', which possibly translates to

wasp A wasp is any insect of the narrow-waisted suborder Apocrita of the order Hymenoptera which is neither a bee nor an ant; this excludes the broad-waisted sawflies (Symphyta), which look somewhat like wasps, but are in a separate suborder. Th ...

, yellowjacket, or the sound made by a wasp. This mountain's name has been officially adopted by the

United States Board on Geographic Names The United States Board on Geographic Names (BGN) is a federal body operating under the United States Secretary of the Interior. The purpose of the board is to establish and maintain uniform usage of geographic names throughout the federal governm ...

Geology

The North Cascades features some of the most rugged topography in the

Cascade Range 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, ...

with craggy peaks, ridges, and deep

glacial valley U-shaped valleys, also called trough valleys or glacial troughs, are formed by the process of glaciation. They are characteristic of mountain glaciation in particular. They have a characteristic U shape in cross-section, with steep, straight s ...

s. Geological events occurring many years ago created the diverse topography and drastic elevation changes over the Cascade Range leading to the various climate differences. These climate differences lead to vegetation variety defining the

ecoregion An ecoregion (ecological region) or ecozone (ecological zone) is an ecologically and geographically defined area that is smaller than a bioregion, which in turn is smaller than a biogeographic realm. Ecoregions cover relatively large areas of l ...

s in this area. The history of the formation of the Cascade Mountains dates back millions of years ago to the late

Eocene The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene' ...

Epoch. With the

North American Plate The North American Plate is a tectonic plate covering most of North America, Cuba, the Bahamas, extreme northeastern Asia, and parts of Iceland and the Azores. With an area of , it is the Earth's second largest tectonic plate, behind the Pacific ...

overriding the

Pacific Plate The Pacific Plate is an oceanic tectonic plate that lies beneath the Pacific Ocean. At , it is the largest tectonic plate. The plate first came into existence 190 million years ago, at the triple junction between the Farallon, Phoenix, and Iza ...

, episodes of volcanic igneous activity persisted. In addition, small fragments of the

oceanic Oceanic may refer to: *Of or relating to the ocean *Of or relating to Oceania **Oceanic climate **Oceanic languages **Oceanic person or people, also called "Pacific Islander(s)" Places * Oceanic, British Columbia, a settlement on Smith Island, ...

and continental lithosphere called

terrane In geology, a terrane (; in full, a tectonostratigraphic terrane) is a crust fragment formed on a tectonic plate (or broken off from it) and accreted or " sutured" to crust lying on another plate. The crustal block or fragment preserves its own ...

s created the North Cascades about 50 million years ago. During the

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...

period dating back over two million years ago, glaciation advancing and retreating repeatedly scoured the landscape leaving deposits of rock debris. The U-shaped cross section of the river valleys are a result of recent glaciation.

Uplift Uplift may refer to: Science * Geologic uplift, a geological process ** Tectonic uplift, a geological process * Stellar uplift, the theoretical prospect of moving a stellar mass * Uplift mountains * Llano Uplift * Nemaha Uplift Business * Uplif ...

and faulting in combination with glaciation have been the dominant processes which have created the tall peaks and deep valleys of the North Cascades.

References

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External links

* Weather
Twisp Mountain
National Park Service North Cascades Mountains of Washington (state) Mountains of Chelan County, Washington Mountains of Okanogan County, Washington North Cascades National Park Cascade Range North Cascades of Washington (state) North American 2000 m summits

Climate

Etymology

Geology

See also

References

External links