Rock Mountain is a mountain summit located northeast of
Stevens Pass
Stevens Pass (elevation ) is a mountain pass through the Cascade Mountains located at the border of King County and Chelan County in Washington, United States. U.S. Route 2 travels over the pass, reaching a maximum elevation of . The Pacific ...
in
Chelan County of
Washington
Washington most commonly refers to:
* George Washington (1732–1799), the first president of the United States
* Washington (state), a state in the Pacific Northwest of the United States
* Washington, D.C., the capital of the United States
** A ...
state.
This peak is situated north of
U.S. Highway 2, approximately midway between Stevens Pass and
Lake Wenatchee
Lake Wenatchee is a glacier- and snowmelt-fed lake situated in the Wenatchee National Forest on the eastern slopes of the Cascade Range, Cascades Mountain Range in the state of Washington (U.S. state), Washington. Lake Wenatchee covers and reache ...
, on land managed by the
Okanogan–Wenatchee National Forest. Rock Mountain is the second-highest point on Nason Ridge, following
Mount Howard, to the northeast.
Rock Mountain was named by
Albert Hale Sylvester.
[Details on places named by Sylvester from ] Precipitation
runoff from the peak drains into tributaries of the
Wenatchee River
The Wenatchee River is a river in the U.S. state of Washington, originating at Lake Wenatchee and flowing southeast for , emptying into the Columbia River immediately north of Wenatchee, Washington. On its way it passes the towns of Plain, Le ...
.
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 (state), Washington and Oregon to Northern California. It includes both non-volcanic mountains, such as m ...
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 various climate differences.
The history of the formation of the Cascade Mountains dates back millions of years ago to the late
Eocene
The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...
Epoch.
With the
North American Plate overriding the
Pacific Plate, episodes of
volcanic igneous activity persisted.
[ ]Glacier Peak
Glacier Peak or Dakobed (known in the Sauk-Suiattle dialect of the Lushootseed language as "Tda-ko-buh-ba" or "Takobia") is the most isolated of the five major stratovolcanoes (composite volcanoes) of the Cascade Volcanoes, Cascade Volcanic Arc ...
, a stratovolcano
A stratovolcano, also known as a composite volcano, is a typically conical volcano built up by many alternating layers (strata) of hardened lava and tephra. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile with ...
that is north of Rock Mountain, began forming in the mid-Pleistocene.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
A lithosphere () is the rigid, outermost rocky shell of a terrestrial planet or natural satellite. On Earth, it is composed of the crust and the lithospheric mantle, the topmost portion of the upper mantle that behaves elastically on time sc ...
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 d ...
s created the North Cascades
The North Cascades are a section of the Cascade Range of western North America. They span the border between the Provinces and territories of Canada, Canadian province of British Columbia and the U.S. state of Washington (state), Washington and ...
about 50 million years ago.[
During the ]Pleistocene
The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...
period dating back over two million years ago, glaciation advancing and retreating repeatedly scoured and shaped the landscape.[ Glaciation was most prevalent approximately , and most valleys were ice-free by .][Beckey, Fred W. Cascade Alpine Guide, Climbing and High Routes. Seattle, WA: Mountaineers Books, 2008.] Uplift 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.
Climate
Lying east of the Cascade
Cascade, or Cascading may refer to:
Science and technology Science
* Air shower (physics), a cascade (particle shower) of subatomic particles and ionized nuclei
** Particle shower, a cascade of secondary particles produced as the result of a high ...
crest, the area around Rock Mountain is a bit drier than areas to the west. Summers can bring warm temperatures and occasional thunderstorms. Weather front
A weather front is a boundary separating air masses for which several characteristics differ, such as air density, wind, temperature, and humidity. Disturbed and unstable weather due to these differences often arises along the boundary. For ins ...
s originating in the Pacific Ocean travel east toward 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 many of those in the ...
. As fronts approach, they are forced upward by the peaks of the Cascade Range, causing them to drop their moisture in the form of rain or snow onto the Cascades (Orographic lift
Orographic lift occurs when an air mass is forced from a low elevation to a higher elevation as it moves over rising terrain. As the air mass gains altitude it quickly cools down adiabatically, which can raise the relative humidity to 100% and cr ...
). As a result, the western slopes of the Cascades experience 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.
Gallery
File:View on the Nason Ridge.jpg, Southeast aspect
File:Nason Ridge from McCausland.jpg, Mt. Howard (left) and Rock Mountain (right) in this view looking east from Mt. McCausland
File:Rock Mountain, to the east.jpg, West aspect
See also
* Geology of the Pacific Northwest
The geology of the Pacific Northwest includes the composition (including rock, minerals, and soils), structure, physical properties and the processes that shape the Pacific Northwest region of North America. The region is part of the Ring of Fir ...
* Geography of the North Cascades
References
{{Reflist
External links
* Weather forecast
Rock Mountain
* Climbing Rock Mountain
YouTube
Mountains of Chelan County, Washington
North Cascades of Washington (state)
Two-thousanders of the United States