Sinister Peak () is in
Mount Baker-Snoqualmie and
Wenatchee National Forests in the U.S. 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 ...
.
It is situated in
Glacier Peak Wilderness and the
North Cascades. Not quite east of
Dome Peak, Sinister Peak is along a high ridge connecting the two peaks. The
Chickamin Glacier is on the north slopes of Sinister Peak while the
Garden Glacier
Garden Glacier is in Wenatchee and Mount Baker-Snoqualmie National Forests in the U.S. state of Washington. Garden Glacier is in two sections, located on the south and east slopes of Sinister Peak. The glacier is along the original approach route ...
is just southeast. Though some of the routes to the summit are technical, it can be reached by a moderate scramble.
Climate
Sinister Peak is located in the
marine west coast climate zone of western
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 th ...
.
[Beckey, Fred W. Cascade Alpine Guide, Climbing and High Routes. Seattle, WA: Mountaineers Books, 2008.] 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 conti ...
, 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 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.
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 and ridges, 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, and
granite
Granite () is a coarse-grained ( phaneritic) intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies un ...
spires. Geological events occurring many years ago created the diverse topography and drastic elevation changes over the Cascade Range leading to various climate differences.
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 that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', ...
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 Paci ...
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 I ...
, episodes of
volcanic igneous activity persisted.
[ In addition, small fragments of the oceanic 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 ow ...
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
* Upli ...
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.
See also
Geography of the North Cascades
The geography of the North Cascades describes a range of rugged mountains in British Columbia, Canada and Washington, United States. In Canada, the range is officially named the Cascade Mountains but is commonly referred to as the Canadian Casca ...
References
{{reflist
External links
* Sinister Peak
Weather forecast
Mountains of Washington (state)
Mountains of Skagit County, Washington
Mountains of Chelan County, Washington
North Cascades
Cascade Range
North American 2000 m summits