Snowgrass Mountain is a mountain summit located 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. Snowgrass Mountain is situated northeast of Frosty Pass and within the

Alpine Lakes Wilderness The Alpine Lakes Wilderness is a large National Wilderness Preservation System, wilderness area spanning the Central Cascades of Washington (state), Washington state in the United States. The wilderness is located in parts of Wenatchee National ...

. Snowgrass Mountain is the second-highest peak in the

Chiwaukum Mountains The Chiwaukum Mountains are a north–south mountain range in central Washington, United States. They stretch from Snowgrass Mountain at , to . The mountains are made of schist, part of the Nason terrane. The original rock in the Nason terrane ...

which are a subrange of 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 ...

. The nearest higher neighbor is Big Chiwaukum, to the north. Precipitation runoff from Snowgrass 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 ...

Climate

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 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 (

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 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.

Geology

The Alpine Lakes Wilderness features some of the most rugged topography in the

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 (phanerite, phaneritic) intrusive rock, 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 coo ...

walls spotted with over 700 mountain lakes. Geological events occurring many years ago created the diverse topography and drastic elevation changes over the Cascade Range leading to the various climate differences. Snowgrass Mountain is composed of

schist Schist ( ) is a medium-grained metamorphic rock generally derived from fine-grained sedimentary rock, like shale. It shows pronounced ''schistosity'' (named for the rock). This means that the rock is composed of mineral grains easily seen with a l ...

, part of the Nason

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 ...

laid down 210 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 last glacial retreat in the Alpine Lakes area began about 14,000 years ago and was north of the Canada–US border by 10,000 years ago. The U-shaped cross section of the river valleys is a result of that 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 Alpine Lakes Wilderness area.

Gallery

File:Snowgrass Mountain green.jpg, Snowgrass Mountain File:Snowgrass sunrise.jpg, South-southeast aspect at sunrise File:Snowgrass.WA.jpg, South-southeast aspect

References

{{reflist

External links

* Weather forecast
Snowgrass MountainAlpine Lakes Wilderness (Okanogan-Wenatchee National Forest)
U.S. Forest Service Mountains of Washington (state) Mountains of Chelan County, Washington Cascade Range Two-thousanders of the United States

Climate

Geology

See also

Gallery

References

External links