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Cochetopa Hills

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Coordinates: 38°19′20″N 106°28′26″W / 38.3221025°N 106.4738221°W / 38.3221025; -106.4738221
From Wikipedia, the free encyclopedia
Cochetopa Hills
Windy Peak along the Continental Divide in the Cochetopa Hills
Highest point
PeakLong Branch Baldy
Elevation11,974 ft (3,650 m)
Coordinates38°19′20″N 106°28′26″W / 38.3221025°N 106.4738221°W / 38.3221025; -106.4738221[1]
Geography
Cochetopa Hills is located in Colorado
Cochetopa Hills
Cochetopa Hills
CountryUnited States
StateColorado
CountySaguache[2]
Parent rangeSan Juan Mountains, Rocky Mountains

The Cochetopa Hills[3] are a mountain range on the Continental Divide in Saguache County, Colorado, United States. The Cochetopa Hills are a sub-range of the San Juan Mountains and are located in the Gunnison National Forest and Rio Grande National Forest. The range extends from Marshall Pass southwest 50 miles (80 km) along the winding crest of the divide to Saguache Park. The high point of the Cochetopa Hills is Long Branch Baldy at an elevation of 11,974 feet (3,650 m).[2][4][5]

The Cochetopa Hills form a notable low-elevation span along the Continental Divide in southern Colorado. The peaks in the adjacent Sawatch Range to the northeast and the San Juan Mountains to the southwest are higher with elevations over 13,000 feet (3,962 m). Within the Cochetopa Hills are Cochetopa Pass (elevation 10,067 feet (3,068 m)) and North Pass (elevation 10,135 feet (3,089 m), which were historically important routes across the divide for Native Americans. Cochetopa is the Ute word for "gate of buffaloes." Today, the Cochetopa Hills are traversed by one paved road, Colorado Highway 114, which crosses the divide at North Pass.[5][6]

Geology

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The Cochetopa Hills are dominated by Tertiary volcanic rocks, including lavas, ash flow tuffs, and breccias. These materials originated from over a dozen volcanoes and multiple eruptions in the San Juan volcanic field. The rocks exposed today are from eruptions 35 million years ago to 26 million years ago.[7][8]

After major eruptions emptied the magma chamber below these volcanoes, the overlying rock could collapse and produce a sunken crater called a caldera. Evidence of such calderas are found throughout the San Juan Volcanic Field, including where the Cochetopa Hills occur today. One of the earliest of these volcanoes was the North Pass Caldera, which was active 33 million years ago. Through time, the caldera filled with additional volcanic material ejected from other volcanoes, and subsequently erosion reshaped the landscape making the ancient caldera now difficult to detect. However, just to the north of the Cochetopa Hills is the Cochetopa Caldera, a younger collapsed volcano which was active 27 million years ago. This caldera is better preserved with the rhyolitic Cochetopa Dome rising from the caldera center. Today, the Cochetopa Hills mark the southern rim of the Cochetopa Caldera.[7][8]

Evidence of glaciation is present at the highest elevations of the Cochetopa Hills. Glacial cirques are located on the northeast and eastern sides of Long Branch Baldy where tarns and glacial deposits are found.[8]

Climate

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The Cochetopa Hills' climate is classified as a subarctic climate (Dfc) in the Köppen system, with cold, snowy winters and cool summers. It receives precipitation as snow in winter and as thunderstorms in summer, with June typically being a drier month.[9][10][11]

References

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  1. ^ "Long Branch Baldy". Geographic Names Information System. United States Geological Survey, United States Department of the Interior. Retrieved 19 March 2024.
  2. ^ a b "Cochetopa Hills". Geographic Names Information System. United States Geological Survey, United States Department of the Interior. Retrieved 19 March 2024.
  3. ^ Pronounced /koʊtʃɪˈtoʊpə/ ⓘ or sometimes locally /koʊtʃɪˈtoʊp/ ⓘ.
  4. ^ Ormes, Robert M. (1992). Guide to the Colorado Mountains (9 ed.). Denver, Colorado: The Colorado Mountain Club. ISBN 0-917895-38X.
  5. ^ a b Benson, Maxine (1994). 1001 Colorado Place Names. Lawrence: University Press of Kansas. ISBN 0-7006-0632-7.
  6. ^ Helmuth, Ed; Helmuth, Gloria (1994). The Passes of Colorado: An Encyclopedia of Watershed Divides. Boulder, Colorado: Pruett Publishing Company. ISBN 0-87108-841-X.
  7. ^ a b Cappa, J.A.; Wallace, C.A. (1999). Geology and Mineral Resources of Saguache County, Colorado. Resource Series RS-44. Denver, Colorado: Colorado Geological Survey.
  8. ^ a b c Lipman, Peter W. (2012). Geologic Map of the Cochetopa Park and North Pass Calderas, Northeastern San Juan Mountains, Colorado. Scientific Investigations Map 3123. United States Geological Survey.
  9. ^ Doesken, Nolan J.; Pielke, Sr., Roger A.; Bliss, Odilia A. P. (2003). "Climate of Colorado". Fort Collins, Colorado: Colorado Climate Center. Retrieved 4 March 2024.
  10. ^ Beck, H.E.; et al. (2023). "High-resolution (1 km) Köppen-Geiger maps for 1901–2099 based on constrained CMIP6 projections". Scientific Data. 10 (724). doi:10.1038/s41597-023-02549-6. PMC 10593765. Retrieved 24 March 2024.
  11. ^ "Climate zones on the move: Historical and predicted future changes in the global distribution of Köppen-Geiger climate zones". Canberra, Australia: Haizea Analytics. Retrieved 24 March 2024.
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