| Big Snow Mountain | |
|---|---|
 Big Snow Mountain fromSnoqualmie Mountain | |
| Highest point | |
| Elevation | 6,680 ft (2,036 m)[1] |
| Prominence | 1,360 ft (415 m)[1] |
| Parent peak | Overcoat Peak (7,432 ft)[2] |
| Isolation | 3.74 mi (6.02 km)[2] |
| Coordinates | 47°32′06″N121°21′58″W / 47.534984°N 121.366119°W /47.534984; -121.366119[1] |
| Geography | |
  Big Snow Mountain Location in Washington Show map of Washington (state) Big Snow Mountain Location in the United States Show map of the United States | |
| Country | United States |
| State | Washington |
| County | King |
| Protected area | Alpine Lakes Wilderness |
| Parent range | Cascade Range |
| Topo map | USGSBig Snow Mountain |
| Geology | |
| Rock type | Keechelusandesite |
| Climbing | |
| First ascent | 1917 byThe Mountaineers[3] |
| Easiest route | Scrambling |
Big Snow Mountain is a prominent 6,680-foot (2,040-metre) mountain summit located 7 mi (11 km) north ofSnoqualmie Pass in theAlpine Lakes Wilderness in easternKing County ofWashington state.[4] It is part of theCascade Range and is situated on land managed byMount Baker-Snoqualmie National Forest. Precipitationrunoff from the mountain drains into tributaries of theSnoqualmie andSkykomish Rivers. The nearest higher peak isOvercoat Peak, 3.75 mi (6.04 km) to the east-southeast.[1]
Big Snow Mountain is located in themarine west coast climate zone of western North America.[3]Weather fronts originating in the Pacific Ocean travel northeast toward theCascade Mountains. 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). As a result, the west side of the Cascades experiences high precipitation, especially during the winter months in the form of snowfall. Because ofmaritime influence, snow tends to be wet and heavy, resulting in highavalanche danger.[3] 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.[3]
The Alpine Lakes Wilderness features some of the most rugged topography in theCascade Range with craggy peaks and ridges, deepglacial valleys, andgranite walls spotted with over 700 mountain lakes.[5] 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.[6] With theNorth American Plate overriding thePacific Plate, episodes ofvolcanic igneous activity persisted.[6] In addition, small fragments of theoceanic andcontinental lithosphere calledterranes created theNorth Cascades about 50 million years ago.[6]
During thePleistocene period dating back over two million years ago, glaciation advancing and retreating repeatedly scoured and shaped the landscape.[6] 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.[6] The U-shaped cross section of the river valleys is a result of that recent glaciation.Uplift andfaulting in combination with glaciation have been the dominant processes which have created the tall peaks and deep valleys of the Alpine Lakes Wilderness area.
