North Star Mountain

North Star Mountain is an 8,096-foot (2,468-metre) mountain summit located in the Glacier Peak Wilderness of the North Cascades, in Chelan County of Washington state.[4] Its nearest neighbor is Cloudy Peak 0.9 mi (1.4 km) to the southwest, and the nearest higher neighbor is Bonanza Peak, 1.9 mi (3.1 km) to the northeast. North Star Mountain was originally named Bonanza Peak, and vice versa, but the USGS’ first 1904 topographic map of the region mistakenly interchanged the names.[5] Precipitation runoff from North Star drains into Agnes Creek and Railroad Creek, both tributaries of the Chelan River.

North Star Mountain
North Star centered, with Cloudy Peak upper right
As seen from Suiattle Pass
Highest point
Elevation8,096 ft (2,468 m) [1]
Prominence936 ft (285 m) [1]
Parent peakBonanza Peak 9,511 ft[2]
Isolation1.35 mi (2.17 km) [2]
Coordinates48°13′22″N 120°54′03″W [1]
Geography
North Star Mountain
Location in Washington
North Star Mountain
Location in the United States
LocationGlacier Peak Wilderness
Chelan County, Washington, U.S.
Parent rangeNorth Cascades
Cascade Range
Topo mapUSGS Suiattle Pass
Geology
Age of rockCretaceous
Climbing
Easiest routeScrambling[3]

Geology

North Star Mountain is located in the Cloudy Pass batholith, an intrusive formation that was formed approximately 20 million years ago, during the early Miocene.[3][6] 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] Glacier Peak, a stratovolcano that is 12.5 mi (20.1 km) southwest of North Star Mountain, began forming in the mid-Pleistocene.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 and shaped the landscape.[7] Glaciation was most prevalent approximately 18,000 years ago, and most valleys were ice-free by 12,000 years ago.[3] 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. Subduction and tectonic activity in the area began during the late cretaceous period, about 90 million years ago. Extensive volcanic activity began to take place in the oligocene, about 35 million years ago.[8]

Climate

North Star Mountain is located in the marine west coast climate zone of western North America.[3] 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.[3] This climate supports the Grant Glacier in a cirque on the north side of the mountain. 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] Because of maritime influence, snow tends to be wet and heavy, resulting in high avalanche danger.[3]

See also

References
North Star Mountain is the nondescript feature in upper right with patches of snow, with Bonanza Peak looming behind it. This view from Plummer Mountain
  1. "North Star Mountain, Washington". Peakbagger.com.
  2. "North Star Mountain - 8,096' WA". listsofjohn.com. Retrieved 2020-05-21.
  3. Beckey, Fred W. Cascade Alpine Guide, Climbing and High Routes. Seattle, WA: Mountaineers Books, 2008.
  4. "North Star Mountain". Geographic Names Information System. United States Geological Survey. Retrieved 2020-05-21.
  5. Majors, Harry M. (1975). Exploring Washington. Van Winkle Publishing Co. p. 44. ISBN 978-0918664006.
  6. CLOUDY PASS BATHOLITH AND ASSOCIATED ROCKS USGS
  7. Kruckeberg, Arthur (1991). The Natural History of Puget Sound Country. University of Washington Press.
  8. "North Cascades Geology". United States Geological Survey. Archived from the original on August 1, 2013. Retrieved July 29, 2013.
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