Amphitheater Mountain is an multi-peak mountain located in Okanogan County in

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 on ...

state. It is part of the Okanogan Range which is a sub-range of the North Cascades and

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, ...

. The mountain is situated on the east side of the Cascade crest, in the

Pasayten Wilderness The Pasayten Wilderness is a protected area located within Okanogan–Wenatchee National Forest and Mount Baker National Forest in Washington state, centered on the Three Forks () of the Pasayten River, a tributary of the Similkameen River. Al ...

, on land administered by the

Okanogan–Wenatchee National Forest The Okanogan National Forest is a U.S. National Forest located in Okanogan County in north-central Washington, United States. The forest is bordered on the north by British Columbia, on the east by Colville National Forest, on the south by the ...

. The sprawling Amphitheater Mountain has several sub-peaks including the South Peak (), West Peak (), and North Peak (). The nearest higher peak is

Cathedral Peak Cathedral Peak may be any of several mountains, typically those with steep sides and towers reminiscent of a cathedral. In the United States alone, the USGS identifies 17 summits named "Cathedral Peak". In other countries: *Cathedr ...

, to the north. The

Pacific Northwest Trail The Pacific Northwest Trail (PNT) is a 1200-mile hiking trail running from the Continental Divide in Montana to the Pacific Ocean on Washington's Olympic Coast. Along the way, the PNT crosses three national parks, seven national forests, and two ...

traverses below the north slope of Amphitheater Mountain as it crosses Cathedral Pass. 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 Amphitheater Mountain drains west into Cathedral Fork, or east into Cathedral Creek.

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 northeast 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 or snowfall onto the Cascades ( Orographic lift). As a result, the west side of the North Cascades experiences higher precipitation than the east side, 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.

Geology

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

with craggy peaks, spires, 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. Amphitheater Mountain from Cathedral Pass

Amphitheater Mountain from Cathedral Pass

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 area.

Climbing Routes

Established rock climbing routes on Amphitheater Mountain:Amphitheatre Mountain Rock Climbing
Mountain Project * ''Pilgrimage to Mecca'' - - 4 pitches * ''Finger of Fatwa'' - - 5 pitches * North Ridge - - 5 pitches * Middle Finger Buttress, Left Side - - 4 pitches * Middle Finger Buttress, Right Side - - 7 pitches

References

{{reflist

External links

* Weather forecast
Amphitheatre Mountain
North Cascades Mountains of Washington (state) Mountains of Okanogan County, Washington Cascade Range North American 2000 m summits

Climate

Geology

Climbing Routes

See also

References

External links