The Absaroka Range is a sub- range of the

Rocky Mountains The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in great-circle distance, straight-line distance from the northernmost part of Western Can ...

in the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

. The range stretches about across the

Montana Montana ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States. It is bordered by Idaho to the west, North Dakota to the east, South Dakota to the southeast, Wyoming to the south, an ...

–

Wyoming Wyoming ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States, Western United States. It borders Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho t ...

border, and at its widest, forming the eastern boundary of

Yellowstone National Park Yellowstone National Park is a List of national parks of the United States, national park of the United States located in the northwest corner of Wyoming, with small portions extending into Montana and Idaho. It was established by the 42nd U ...

along Paradise Valley, and the western side of the

Bighorn Basin The Bighorn Basin is a plateau region and intermontane basin, approximately 100 miles (160 km) wide, in north-central Wyoming in the United States. It is bounded by the Absaroka Range on the west, the Pryor Mountains on the north, the Bigho ...

. The range borders the Beartooth Mountains to the north and the Wind River Range to the south. The northern edge of the range rests along I-90 and

Livingston, Montana Livingston is a city and the county seat of Park County, Montana, United States. It is in southwestern Montana, on the Yellowstone River, north of Yellowstone National Park. As of the 2020 census, the population of the city was 8,040. Hist ...

. The highest peak in the range is Francs Peak, located in

at . There are 46 other peaks over .

Geography

The range is drained by the

Yellowstone River The Yellowstone River is a tributary of the Missouri River, approximately long, in the Western United States. Considered the principal tributary of the upper Missouri, via its own tributaries it drains an area with headwaters across the mountain ...

and various tributaries, including the Bighorn River. Most of the range lies within protected lands including Yellowstone Park, the Absaroka-Beartooth Wilderness, North Absaroka Wilderness, Teton Wilderness, and Washakie Wilderness, spanning the Bridger-Teton National Forest, Custer National Forest, Gallatin National Forest, and Shoshone National Forest. U.S. Highway 212 from

Billings, Montana Billings is the most populous Lists of populated places in the United States, city in the U.S. state of Montana, with a population of 117,116 as of the 2020 United States census, 2020 census. Located in the south-central portion of the state, i ...

to Yellowstone climbs over Beartooth Pass in the neighboring Beartooth Mountains before winding through the Absarokas to the northeast gate of

. It is only open during the summer. U.S Route 14/16/20 follows the Shoshone River from Cody through the range to the eastern gate of the park.

Climate

History

The range is named after the Absaroka Native People. The name is derived from the Hidatsa name for the Crow people; it means "children of the large-beaked bird." (In contrast, the Crow name, ''Awaxaawe Báaxxioo'', means "Pointed Mountains ike Sand Castles")

John Colter John Colter (c.1770–1775 – May 7, 1812 or November 22, 1813) was a member of the Lewis and Clark Expedition (1804–1806). Though party to one of the more famous expeditions in history, Colter is best remembered for explorations he made ...

, who may have been the first white person to visit the area, probably traveled along the foot of the Absarokas in 1807 during his reconnaissance of the Yellowstone region. Early explorers also included Gustavus Cheyney Doane and Nathaniel P. Langford, who climbed the summit of Colter Peak in 1870. The proposed state of Absaroka shared the same age with the mountain range. The USS ''Absaroka'' was named after this mountain range.

Geology

Geologically, the section of the range in Wyoming consists of volcanic breccia, whereas there is a transition to

granite Granite ( ) is a coarse-grained (phanerite, phaneritic) intrusive rock, intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly coo ...

and gneiss bedrock further north of the state line.

Absaroka Volcanic Province

Igneous rock Igneous rock ( ), or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic. Igneous rocks are formed through the cooling and solidification of magma or lava. The magma can be derived from partial ...

s of the Absaroka Volcanic Province cover an area of approximately in southwestern

and northwestern

, including roughly one third of

. These

extrusive Extrusive rock refers to the mode of igneous volcanic rock formation in which hot magma from inside the Earth flows out (extrudes) onto the surface as lava or explodes violently into the atmosphere to fall back as pyroclastics or tuff. In contr ...

rocks were erupted during the

Eocene The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...

Epoch In chronology and periodization, an epoch or reference epoch is an instant in time chosen as the origin of a particular calendar era. The "epoch" serves as a reference point from which time is measured. The moment of epoch is usually decided b ...

of the

Paleogene The Paleogene Period ( ; also spelled Palaeogene or Palæogene) is a geologic period and system that spans 43 million years from the end of the Cretaceous Period Ma (million years ago) to the beginning of the Neogene Period Ma. It is the fir ...

Period.

Radiometric dating Radiometric dating, radioactive dating or radioisotope dating is a technique which is used to Chronological dating, date materials such as Rock (geology), rocks or carbon, in which trace radioactive impurity, impurities were selectively incorporat ...

has shown that eruptive activity lasted from about . The eroded remnants of many large

stratovolcano A stratovolcano, also known as a composite volcano, is a typically conical volcano built up by many alternating layers (strata) of hardened lava and tephra. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile with ...

es are found in the area. The dissection of these long

extinct volcano A volcano is commonly defined as a vent or fissure in the Crust (geology), crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and volcanic gas, gases to escape from a magma chamber below the surface. On Earth ...

es by

erosion Erosion is the action of surface processes (such as Surface runoff, water flow or wind) that removes soil, Rock (geology), rock, or dissolved material from one location on the Earth's crust#Crust, Earth's crust and then sediment transport, tran ...

allows

geologist A geologist is a scientist who studies the structure, composition, and History of Earth, history of Earth. Geologists incorporate techniques from physics, chemistry, biology, mathematics, and geography to perform research in the Field research, ...

s to see volcanic structures that are impossible to see in

active volcano An active volcano is a volcano that is currently erupting, or has the potential to erupt in the future. Conventionally it is applied to any that have erupted during the Holocene (the current geologic epoch that began approximately 11,700 years ...

es. Many terms now widely used in

volcanology Volcanology (also spelled vulcanology) is the study of volcanoes, lava, magma and related geology, geological, geophysical and geochemistry, geochemical phenomena (volcanism). The term ''volcanology'' is derived from the Latin language, Latin ...

originated in nineteenth century field studies of these ancient volcanoes.

Gallery

File:Pilot and Index Peaks.jpg, Pilot and Index peaks in the Absaroka Mountains File:WestslopeAbsarokaRangeMontana.jpg, Western face of Absarokas from Paradise Valley (Montana) File:Livingston MT 03.jpg, Northern Absaroka range as seen from

File:NorthernAbsarokasNearLivingstonMontana2010.jpg, Northwest expanse of Absarokas as viewed from over Livingston, Montana File:Smoke over the Absarokas.jpg, The mountains on August 19, 1988, smoky due to the Yellowstone fires of 1988

References

External links

* {{Authority control Ranges of the Rocky Mountains Mountain ranges of Wyoming Mountain ranges of Montana Greater Yellowstone Ecosystem Landforms of Park County, Montana