Hillman Peak

Hillman Peak was named by William Gladstone Steel for John Wesley Hillman (1832–1915), a prospector who discovered Crater Lake on June 12, 1853. The peak's "Hillman Peak" toponym was officially adopted in 1928 by the United States Board on Geographic Names. Variant names prior to 1928 included Glacier Peak and Maxwell Peak.

Based on the Köppen climate classification, Hillman Peak has a subalpine climate.{{cite journal | author = Peel, M. C. |author2=Finlayson, B. L. |author3=McMahon, T. A. | year = 2007 | title = Updated world map of the Köppen−Geiger climate classification | journal = Hydrol. Earth Syst. Sci. | volume = 11 | issn = 1027-5606}} Most weather fronts originate in the Pacific Ocean, and travel east toward the Cascades where they are forced upward by the range (Orographic lift), causing them to drop their moisture in the form of rain or snowfall. As a result, the Cascades experience high precipitation, especially during the winter months in the form of snowfall. Winter temperatures can drop below {{convert|10|°F|°C}} with wind chill factors below {{convert|0|°F|°C}}. In the Crater Lake area, winter lasts eight months with an average snowfall of 41 feet (12.5 m) per year.[https://www.nps.gov/crla/planyourvisit/weather.htm Crater Lake Climate, National Park Service, Retrieved 2023-01-23.] Rim Drive is only open during the summer due to the heavy snowfall as the road is covered by more than {{convert|20|ft|m}} of snow with drifts as deep as {{convert|60|ft|m}} in some areas.[http://www.nps.gov/archive/crla/brochures/facts.htm "Facts and Figures"], National Park Service, United States Department of Interior, Crater Lake, Oregon, November 2001. 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.

Hillman Peak was created when Mount Mazama, a large stratovolcano erupted violently approximately 7,700 years ago and formed on the caldera rim. The peak is the remnant of a parasitic cone on the western flank of Mount Mazama, such that when the caldera formed, the eastern half of the Hillman cone disappeared. The peak is composed of lava flows containing pyroxene and hornblende andesites and breccias.{{cite web|url=https://www.craterlakeinstitute.com/research-at-crater-lake/geology/historic-geology/geology-howell-williams-1942/40-01/|title=The Hillman Cone, Craterlakeinstitute.com|access-date=2023-01-28}} Evidence suggests that the pre-eruption Hillman cone acted as a cleaver which was never entirely covered by glacial ice.Ann G. Harris, Esther Tuttle, Sherwood D. Tuttle (2004), Geology of National Parks, Volume 1, Kendall/Hunt Publishing Company, {{ISBN|9780787299705}}, p. 536.

According to the Global Volcanism Program (GVP), Hillman Peak is classified as a subfeature stratovolcano of Mount Mazama.

• {{Portal-inline|Mountains|size=tiny}}
• Applegate Peak
• Llao Rock

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• [https://www.ngs.noaa.gov/cgi-bin/ds_mark.prl?PidBox=NZ1036 National Geodetic Survey Data Sheet]
• [http://www.nps.gov/crla/ Crater Lake National Park] (National Park Service)
• Weather forecast: [https://www.yr.no/en/forecast/daily-table/2-5731358/United%20States/Oregon/Klamath/Hillman%20Peak Hillman Peak]

{{Volcanoes of Oregon|state=collapsed}}

{{Crater Lake |state=collapsed}}

Category:Cascade Range

Category:Cascade Volcanoes

Category:Volcanoes of Klamath County, Oregon

Category:Crater Lake National Park

Category:Mountains of Klamath County, Oregon

Category:Mountains of Oregon

Category:Two-thousanders of the United States

Category:Stratovolcanoes of Oregon