Round Mountain
[
] is a 5,369-foot mountain summit at the western edge of 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 ...
, in
Skagit County
Skagit County is a county in the U.S. state of Washington. As of the 2020 census, the population was 129,523. The county seat and largest city is Mount Vernon. The county was formed in 1883 from Whatcom County and is named for the Upper and ...
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. It is located nine miles northwest of
Darrington, Washington
Darrington is a town in Snohomish County, Washington, Snohomish County, Washington (state), Washington, United States. It is located in a North Cascades mountain valley formed by the Sauk River (Washington), Sauk and Stillaguamish River, North F ...
, and is situated on land administered by the
Mount Baker-Snoqualmie National Forest. Round Mountain is remarkable for its 4,840 feet of
prominence
In topography, prominence or relative height (also referred to as autonomous height, and shoulder drop in US English, and drop in British English) measures the height of a mountain or hill's summit relative to the lowest contour line encircling ...
which ranks as the most in Skagit County, and eighth-most of all the mountains in Washington state.
The nearest higher peak is
Whitehorse Mountain, to the south-southeast.
[ Precipitation runoff from Round Mountain drains into tributaries of the ]Stillaguamish River
The Stillaguamish River is a river in the northwestern region of the U.S. state of Washington. It is mainly composed of two forks, the longer North Fork Stillaguamish () and the South Fork Stillaguamish. The two forks join near Arlington. Fro ...
.
Climate
Round Mountain is located in the marine west coast
An oceanic climate, also known as a marine climate or maritime climate, is the temperate climate sub-type in Köppen classification represented as ''Cfb'', typical of west coasts in higher middle latitudes of continents, generally featuring co ...
climate zone of western North America.[Beckey, Fred W. Cascade Alpine Guide, Climbing and High Routes. Seattle, WA: Mountaineers Books, 2008.] Most 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 coming off the Pacific Ocean travel northeast 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 (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 ...
), causing them to drop their moisture in the form of rain or snowfall 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.
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 the various climate differences. These climate differences lead to vegetation variety defining the ecoregion
An ecoregion (ecological region) is an ecological and geographic area that exists on multiple different levels, defined by type, quality, and quantity of environmental resources. Ecoregions cover relatively large areas of land or water, and c ...
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 ( ) 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.[ 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
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 the landscape leaving deposits of rock debris.[ The U-shaped cross section of the river valleys is a result of recent glaciation. 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.
]
See also
*List of the most prominent summits of the United States
The following sortable table comprises the 200 Topographic prominence, most topographically prominent Summit, mountain peaks of the United States, United States of America.
The summit of a mountain or hill may be measured in three principal w ...
* List of mountain peaks of Washington (state)
References
{{reflist
External links
* Weather forecast
Round Mountain
Mountains of Washington (state)
Mountains of Skagit County, Washington
Cascade Range
Mount Baker-Snoqualmie National Forest
One-thousanders of the United States