| Sheep Mountain | |
|---|---|
 Sheep Mountain reflected in Ramon Lakes at sunrise | |
| Highest point | |
| Elevation | 8,274 ft (2,522 m)[1] |
| Prominence | 2,034 ft (620 m)[1] |
| Listing | List of highest mountain peaks in Washington |
| Coordinates | 48°58′36″N120°23′19″W / 48.976648°N 120.388607°W /48.976648; -120.388607[1] |
| Geography | |
  Sheep Mountain Location in Washington Show map of Washington (state) Sheep Mountain Sheep Mountain (the United States) Show map of the United States | |
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| Interactive map of Sheep Mountain | |
| Location | |
| Parent range | Okanogan Range North Cascades Cascade Range |
| Topo map | USGSAshnola Mountain |
| Geology | |
| Rock type(s) | Granodiorite,Gneiss[2] |
| Climbing | |
| First ascent | 1925 Survey party[2] |
| Easiest route | Hiking Southeast slopes[2] |
Sheep Mountain[3] is an 8,274-foot (2,522-metre) mountain summit located inOkanogan County inWashington state. It is part of theOkanogan Range which is a sub-range of theNorth Cascades andCascade Range. The mountain is situated less than 2 miles (3.2 km) south of theCanada–United States border, on the east side of the Cascade crest, in thePasayten Wilderness, on land managed by theOkanogan–Wenatchee National Forest. The nearest higher peak is Andrew Peak, 8.3 miles (13.4 km) to the east-southeast.[1] ThePacific Northwest Trail traverses the slopes of Sheep Mountain as it crosses Peeve Pass. Precipitationrunoff from Sheep Mountain drains west into Peeve Creek, or east into tributaries ofAshnola River. The mountain was so named because for 40 years the meadows surrounding it were prime grazing land for sheep in the summer, before the protection of wilderness designation.[3]
Mostweather fronts originate in thePacific Ocean, and travel northeast toward theCascade Mountains. As fronts approach theNorth 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.[2]
The North Cascades features some of the most rugged topography in theCascade Range with craggy peaks, spires, bridges, and deepglacial valleys. Geological events occurring many years ago created the diverse topography and drastic elevation changes over the Cascade Range leading to the various climate differences.
The history of the formation of the Cascade Mountains dates back millions of years ago to the lateEocene Epoch.[4] With theNorth American Plate overriding thePacific Plate, episodes ofvolcanic igneous activity persisted.[4] In addition, small fragments of theoceanic andcontinental lithosphere calledterranes created theNorth Cascades about 50 million years ago.[4]
During thePleistocene period dating back over two million years ago, glaciation advancing and retreating repeatedly scoured the landscape leaving deposits of rock debris.[4] The U-shaped cross section of the river valleys is a result of recent glaciation.Uplift andfaulting in combination with glaciation have been the dominant processes which have created the tall peaks and deep valleys of the North Cascades area.
