Gilbert Mountain is an 8,023-foot (2,445-metre) massif located in Okanogan County in Washington state.[4] It is part of the North Cascades Range, and is situated in the Lake Chelan-Sawtooth Wilderness.[1] The northwestern extreme of the Gilbert massif connects to the southern end of Kangaroo Ridge. Precipitation runoff from the mountain drains into the Twisp River. Topographic relief is significant as it rises over 4,000 feet (1,220 meters) above the river in approximately one mile.

Gilbert Mountain
Gilbert Mountain seen from Wallaby Peak
Highest point
Elevation	8,023 ft (2,445 m)[1]
Prominence	1,063 ft (324 m)[1]
Parent peak	Kangaroo Ridge (8,300 ft)[2]
Isolation	2.6 mi (4.2 km)[2]
Coordinates	48°28′51″N 120°34′52″W[1]
Geography
Gilbert Mountain Location in Washington Show map of Washington (state) Gilbert Mountain Gilbert Mountain (the United States) Show map of the United States
Location	Okanogan County, Washington, U.S.
Parent range	North Cascades
Topo map	USGS Gilbert
Climbing
Easiest route	scrambling[3]

Climate

Gilbert Mountain is located in the marine west coast climate zone of western North America.[5] Most weather fronts originate in the Pacific Ocean, and travel northeast toward the Cascade Mountains. As fronts approach the North 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 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.[6] Because of maritime influence, snow tends to be wet and heavy, resulting in high avalanche danger.[6]

Geology

The North Cascades features some of the most rugged topography in the Cascade Range with craggy peaks, ridges, and deep glacial 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. These climate differences lead to vegetation variety defining the ecoregions in this area.

The history of the formation of the Cascade Mountains dates back millions of years ago to the late Eocene Epoch.[7] With the North American Plate overriding the Pacific Plate, episodes of volcanic igneous activity persisted.[7] In addition, small fragments of the oceanic and continental lithosphere called terranes created the North Cascades about 50 million years ago.[7]

During the Pleistocene period dating back over two million years ago, glaciation advancing and retreating repeatedly scoured the landscape leaving deposits of rock debris.[7] The U-shaped cross section of the river valleys are 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

• Geography of the North Cascades
• List of mountain peaks of Washington (state)

References

External links

• Gilbert Mountain weather: Mountain Forecast