The Beartooth Mountains are located in south central Montana and northwest Wyoming , U.S. and are part of the 944,000 acres (382,000 ha) Absaroka-Beartooth Wilderness , within Custer , Gallatin and Shoshone National Forests . The Beartooths are the location of Granite Peak , which at 12,807 feet (3,904 m) is the highest point in the state of Montana. The mountains are just northeast of Yellowstone National Park and are part of the Greater Yellowstone Ecosystem . The mountains are traversed by road via the Beartooth Highway (U.S. 212) with the highest elevation at Beartooth Pass 10,947 ft (3,337 m)). The name of the mountain range has been attributed by the U.S. Forest Service to a rugged peak found in the range, Beartooth Peak, that has the appearance of a bear's tooth. Originally, the Beartooth Mountains were named after Beartooth Butte, a large block of paleozoic sediments on the Beartooth Plateau, and Beartooth Butte was named for a tooth-like structure that projects from the front of the butte.
111-457: The Beartooth Mountains sit upon the larger Beartooth Plateau. The remoteness of the region contributed to its obscurity until the 1870s. The Crow tribe of Native Americans used the valleys of the mountains for hunting game animals and for winter shelter from the harsh winds of the plains. Though trappers entered the region in the 1830s, formal exploration by the U.S. Government did not occur until 1878. While gold had been discovered earlier in
222-723: A Crow camp in the Bighorn valley greeted the Jesuit missionary Pierre-Jean De Smet. From 1842 to around 1852, the Crow traded in Fort Alexander opposite the mouth of the Rosebud. The River Crows charged a moving Blackfeet camp near Judith Gap in 1845. Father Pierre-Jean De Smet mourned the destructive attack on the "petite Robe" band. The Blackfeet chief Small Robe had been mortally wounded and many killed. De Smet worked out
333-527: A Lakota camp destroyed a whole Crow camp at Tongue River the following year. This was likely the most severe attack on a Crow camp in historic time. The Crows put up 300 tipis near a Mandan village on the Missouri in 1825. The representatives of the US government waited for them. Mountain Crow chief Long Hair (Red Plume at Forehead) and fifteen other Crows signed the first treaty of friendship and trade between
444-407: A benchmark to compare others in the northern Rocky Mountains. Most of the current species are currently protected. The mountains are home to many of North America 's largest animals, including one of the few grizzly bear populations in the contiguous United States. There are rare sightings of lynx and wolverines and a population of cougars and recently reintroduced wolves . There are some of
555-408: A distinctive composition or mode or origin. Special names still in wide use include amphibolite, greenschist , phyllite, marble, serpentinite , eclogite, migmatite , skarn , granulite , mylonite, and slate. The basic classification can be supplemented by terms describing mineral content or texture. For example, a metabasalt showing weak schistosity might be described as a gneissic metabasalt, and
666-455: A distinctive layering called foliation (derived from the Latin word folia , meaning "leaves"). Foliation develops when a rock is being shortened along one axis during recrystallization. This causes crystals of platy minerals, such as mica and chlorite , to become rotated such that their short axes are parallel to the direction of shortening. This results in a banded, or foliated, rock, with
777-678: A formal proposal. Environmental advocates continued to push for the area's preservation in order to defend the northern borders of Yellowstone National Park from development. Finally, in 1975 the Beartooths were protected as part of the Absaroka–Beartooth Wilderness . The ecosystem of the Beartooth Mountains is one of the most unique in the Contiguous United States partly due to being part of
888-476: A group of whites with horses on the Yellowstone River. By stealth, they captured the mounts before morning. The Lewis and Clark Expedition did not see the Crow. The first trading post in Crow country was constructed in 1807, known as both Fort Raymond and Fort Lisa (1807–ca. 1813). Like the succeeding forts, Fort Benton (ca. 1821–1824) and Fort Cass (1832–1838), it was built near the confluence of
999-637: A large part of the Earth's crust and form 12% of the Earth's land surface. They are classified by their protolith, their chemical and mineral makeup, and their texture . They may be formed simply by being deeply buried beneath the Earth's surface, where they are subject to high temperatures and the great pressure of the rock layers above. They can also form from tectonic processes such as continental collisions, which cause horizontal pressure, friction, and distortion. Metamorphic rock can be formed locally when rock
1110-754: A long confrontation. Crow chief Blackfoot objected to this incursion and called for resolute U.S. military actions against the Indian trespassers. Due to Sioux attacks on both civilians and soldiers north of the Yellowstone in newly established U.S. territory ( Battle of Pease Bottom , Battle of Honsinger Bluff ), the Commissioner of Indian Affairs advocated the use of troops to force the Sioux back to South Dakota in his 1873 report. Nothing happened. Two years later, in early July 1875, Crow chief Long Horse
1221-469: A marble will not be identical with the amphibolite facies of a pelite. However, the facies are defined such that metamorphic rock with as broad a range of compositions as is practical can be assigned to a particular facies. The present definition of metamorphic facies is largely based on the work of the Finnish geologist, Pentti Eskola , with refinements based on subsequent experimental work. Eskola drew upon
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#17327724837181332-533: A metamorphic rock to be classified in this manner, the protolith should be identifiable from the characteristics of the metamorphic rock itself, and not inferred from other information. Under the British Geological Survey's classification system, if all that can be determined about the protolith is its general type, such as sedimentary or volcanic, the classification is based on the mineral mode (the volume percentages of different minerals in
1443-472: A new Fort Laramie treaty between the Sioux and the U.S. turned 1851 Crow Powder River area into "unceded Indian territory" of the Sioux. "The Government had in effect betrayed the Crows…". On 7 May, the same year, the Crow ceded vast ranges to the US due to pressure from white settlements north of Upper Yellowstone River and loss of eastern territories to the Sioux. They accepted a smaller reservation south of
1554-413: A pelite containing abundant staurolite might be described as a staurolite pelite. [REDACTED] A metamorphic facies is a set of distinctive assemblages of minerals that are found in metamorphic rock that formed under a specific combination of pressure and temperature. The particular assemblage is somewhat dependent on the composition of that protolith, so that (for example) the amphibolite facies of
1665-467: A pipe-hatchet during the fight just west of Chinook, Montana . In the summer of 1834, the Crow (maybe led by chief Arapooish) tried to shut down Fort McKenzie at the Missouri in Blackfeet country. The apparent motive was to stop the trading post's sale to their Indian enemies. Although later described as a month long siege of the fort, it lasted only two days. The opponents exchanged a few shots and
1776-516: A process called metamorphism . The original rock ( protolith ) is subjected to temperatures greater than 150 to 200 °C (300 to 400 °F) and, often, elevated pressure of 100 megapascals (1,000 bar ) or more, causing profound physical or chemical changes. During this process, the rock remains mostly in the solid state, but gradually recrystallizes to a new texture or mineral composition. The protolith may be an igneous , sedimentary , or existing metamorphic rock. Metamorphic rocks make up
1887-464: A reference, and/or with a substantial contribution to the development of geological sciences through history.' Huge expansive plateaus are found at altitudes in excess of 10,000 ft (3,000 m) with over 25 peaks exceeding 12,000 ft (3,700 m). The mountains have over 300 pristine lakes and some waterfalls in excess of 300 ft (100 m). Winters are severe with heavy snow and incessant winds. Approximately 25 small glaciers exist in
1998-519: A relatively mild grade of metamorphism, at temperatures of 350–500 °C (662–932 °F) and pressures of 200–500 MPa (2,000–5,000 bar). They can be divided into a lower group of metabasalts, including rare meta komatiites ; a middle group of meta-intermediate-rock and meta-felsic-rock; and an upper group of metasedimentary rock. The greenstone belts are surrounded by high-grade gneiss terrains showing highly deformed low-pressure, high-temperature (over 500 °C (932 °F)) metamorphism to
2109-533: A site for a single earth lodge on the lower Yellowstone River. Most families lived in tipis or other perishable kinds of homes at the new place. These Indians had left the Hidatsa villages and adjacent cornfields for good, but they had yet to become "real" buffalo hunting Crow following the herds on the open plains. Archaeologists know this "proto-Crow" site in present Montana as the Hagen site. Some time before 1765,
2220-410: A variety of metamorphic facies. Where subduction is taking place, the basalt of the subducting slab is metamorphosed to high-pressure metamorphic facies. It initially undergoes low-grade metamorphism to metabasalt of the zeolite and prehnite-pumpellyite facies , but as the basalt subducts to greater depths, it is metamorphosed to the blueschist facies and then the eclogite facies . Metamorphism to
2331-417: Is a great variety of metamorphic rock types. In general, if the protolith of a metamorphic rock can be determined, the rock is described by adding the prefix meta- to the protolith rock name. For example, if the protolith is known to be basalt , the rock will be described as a metabasalt. Likewise, a metamorphic rock whose protolith is known to be a conglomerate will be described as a metaconglomerate . For
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#17327724837182442-530: Is also prized for building construction and as a medium for sculpture. On the other hand, schist bedrock can pose a challenge for civil engineering because of its pronounced planes of weakness. Metamorphic rocks form one of the three great divisions of rock types. They are distinguished from igneous rocks , which form from molten magma , and sedimentary rocks , which form from sediments eroded from existing rock or precipitated chemically from bodies of water. Metamorphic rocks are formed when existing rock
2553-426: Is called a paired metamorphic belt . The main islands of Japan show three distinct paired metamorphic belts, corresponding to different episodes of subduction. Metamorphic rock is also exposed in metamorphic core complexes , which form in region of crustal extension. They are characterized by low-angle faulting that exposes domes of middle or lower crust metamorphic rock. These were first recognized and studied in
2664-464: Is dominated by metamorphic rock that has reached the amphibolite facies. Within the upper crust, which is the only part of the Earth's crust geologists can directly sample, metamorphic rock forms only from processes that can occur at shallow depth. These are contact (thermal) metamorphism , dynamic (cataclastic) metamorphism , hydrothermal metamorphism , and impact metamorphism . These processes are relatively local in occurrence and usually reach only
2775-476: Is formed as tectonic plates move apart. Hydrothermal metamorphism is extensive here. This is characterized by metasomatism by hot fluids circulating through the rock. This produces metamorphic rock of the greenschist facies. The metamorphic rock, serpentinite , is particularly characteristic of these settings, and represents chemical transformation of olivine and pyroxene in ultramafic rock to serpentine group minerals. Contact metamorphism takes place when magma
2886-464: Is heated by the intrusion of hot molten rock called magma from the Earth's interior. The study of metamorphic rocks (now exposed at the Earth's surface following erosion and uplift) provides information about the temperatures and pressures that occur at great depths within the Earth's crust. Some examples of metamorphic rocks are gneiss , slate , marble , schist , and quartzite . Slate and quartzite tiles are used in building construction. Marble
2997-403: Is injected into the surrounding solid rock ( country rock ). The changes that occur are greatest wherever the magma comes into contact with the rock because the temperatures are highest at this boundary and decrease with distance from it. Around the igneous rock that forms from the cooling magma is a metamorphosed zone called a contact aureole . Aureoles may show all degrees of metamorphism from
3108-405: Is known as burial metamorphism . This tends to produce low-grade metamorphic rock. Much more common is metamorphic rock formed during the collision process itself. The collision of plates causes high temperatures, pressures and deformation in the rocks along these belts. Metamorphic rock formed in these settings tends to shown well-developed schistosity. Metamorphic rock of orogenic belts shows
3219-506: Is sufficiently hard and dense that it is difficult to quarry. However, some quartzite is used as dimension stone , often as slabs for flooring, walls, or stairsteps. About 6% of crushed stone, used mostly for road aggregate, is quartzite. Marble is also prized for building construction and as a medium for sculpture. Schistose bedrock can pose a challenge for civil engineering because of its pronounced planes of weakness. A hazard may exist even in undisturbed terrain. On August 17, 1959,
3330-548: Is the one dominated by Castle Mountain. Crow Nation The Crow , whose autonym is Apsáalooke ( [ə̀ˈpsáːɾòːɡè] ), also spelled Absaroka , are Native Americans living primarily in southern Montana. Today, the Crow people have a federally recognized tribe , the Crow Tribe of Montana , with an Indian reservation , the Crow Indian Reservation , located in the south-central part of
3441-553: Is transformed physically or chemically at elevated temperature, without actually melting to any great degree. The importance of heating in the formation of metamorphic rock was first noted by the pioneering Scottish naturalist, James Hutton , who is often described as the father of modern geology. Hutton wrote in 1795 that some rock beds of the Scottish Highlands had originally been sedimentary rock but had been transformed by great heat. Hutton also speculated that pressure
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3552-400: Is uncertain. Special classifications exist for metamorphic rocks with a volcaniclastic protolith or formed along a fault or through hydrothermal circulation . A few special names are used for rocks of unknown protolith but known modal composition, such as marble, eclogite , or amphibolite . Special names may also be applied more generally to rocks dominated by a single mineral, or with
3663-426: Is used only when very little else is known about the rock that would allow a more definite classification. Textural classifications may be prefixed to indicate a sedimentary protolith ( para- , such as paraschist) or igneous protolith ( ortho- , such as orthogneiss). When nothing is known about the protolith, the textural name is used without a prefix. For example, a schist is a rock with schistose texture whose protolith
3774-475: Is usually devoid of schistosity and forms a tough, equigranular rock. If the rock was originally banded or foliated (as, for example, a laminated sandstone or a foliated calc- schist ) this character may not be obliterated, and a banded hornfels is the product. Contact metamorphism close to the surface produces distinctive low-pressure metamorphic minerals, such as spinel , andalusite, vesuvianite , or wollastonite . Similar changes may be induced in shales by
3885-470: Is very low in silica) to metafelsic-rock (with a high silica content). Where the mineral mode cannot be determined, as is often the case when rock is first examined in the field , then classification must be based on texture. The textural types are: A hornfels is a granofels that is known to result from contact metamorphism. A slate is a fine-grained metamorphic rock that easily splits into thin plates but shows no obvious compositional layering. The term
3996-570: The Basin and Range Province of southwestern North America, but are also found in southern Aegean Sea , in the D'Entrecasteaux Islands , and in other areas of extension. Continental shields are regions of exposed ancient rock that make up the stable cores of continents. The rock exposed in the oldest regions of shields, which is of Archean age (over 2500 million years old), mostly belong to granite-greenstone belts. The greenstone belts contain metavolcanic and metasedimentary rock that has undergone
4107-719: The Bighorn Mountains (Iisiaxpúatachee Isawaxaawúua), Pryor Mountains (Baahpuuo Isawaxaawúua), Wolf Mountains (Cheetiish, or "Wolf Teeth Mountains") and Absaroka Range (also called Absalaga Mountains). Once established in the Valley of the Yellowstone River and its tributaries on the Northern Plains in Montana and Wyoming , the Crow divided into four groups: the Mountain Crow, River Crow, Kicked in
4218-548: The Greater Yellowstone Ecosystem . This space allows a great diversity with 34,375 square miles (89,030 km) of nearly intact wilderness. With the protection to the terrestrial habitats all of the bodies of water are classified as Outstanding National Resource Waters, giving them the highest protections under the Clean Water Act . The cleanliness of the bodies of water led them to be used as
4329-694: The Little Big Horn College . The autonym of the tribe, Apsáalooké or Absaroka, means "children of the large-beaked bird" and was given to them by the Hidatsa , a neighboring and related Siouan-speaking tribe. French interpreters translated the name as gens du corbeau ("people of the crow"), and they became known in English as the Crow. Other tribes also refer to the Apsáalooke as "crow" or "raven" in their own languages. The identity of
4440-944: The Missouri River , then southeast to the confluence of the Yellowstone and Powder rivers (Bilap Chashee, or "Powder River" or "Ash River"), south along the South Fork of the Powder River, confined in the SE by the Rattlesnake Mountains and westwards in the SW by the Wind River Range . Their tribal area included the river valleys of the Judith River (Buluhpa'ashe, or "Plum River"), Powder River, Tongue River , Big Horn River and Wind River as well as
4551-450: The atoms and ions in solid crystals to migrate, thus reorganizing the crystals, while high pressures cause solution of the crystals within the rock at their point of contact. Metamorphic rocks are characterized by their distinctive mineral composition and texture. Because every mineral is stable only within certain limits, the presence of certain minerals in metamorphic rocks indicates the approximate temperatures and pressures at which
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4662-402: The crystallization of igneous rocks. They are stable at high temperatures and pressures and may remain chemically unchanged during the metamorphic process. Metamorphic rocks are typically more coarsely crystalline than the protolith from which they formed. Atoms in the interior of a crystal are surrounded by a stable arrangement of neighboring atoms. This is partially missing at the surface of
4773-842: The fur trade , the Crow had migrated to this area from the Ohio Eastern Woodland area of present-day Ohio, settling south of Lake Winnipeg . From there, they were pushed to the west by the Cheyenne. Both the Crow and the Cheyenne were pushed farther west by the Lakota, who took over the territory west of the Missouri River, reaching past the Black Hills of South Dakota to the Big Horn Mountains of Wyoming and Montana. The Cheyenne eventually became allies of
4884-520: The 1850s, a vision by Plenty Coups , then a boy, but who later became their greatest chief, was interpreted by tribal elders as meaning that the whites would become dominant over the entire country, and that the Crow, if they were to retain any of their land, would need to remain on good terms with the whites. By 1851, the more numerous Lakota and Cheyenne were established just to the south and east of Crow territory in Montana. These enemy tribes coveted
4995-978: The Americans deal with them regarding any intrusion into these areas. The Treaty of Fort Laramie of 1851 with the United States confirmed as Crow lands a large area centered on the Big Horn Mountains: the area ran from the Big Horn Basin on the west, to the Musselshell River on the north, and east to the Powder River ; it included the Tongue River basin . But for two centuries the Cheyenne and many bands of Lakota Sioux had been steadily migrating westward across
5106-514: The Beartooths with Grasshopper Glacier being one of the more distinctive. The highest peaks of the Beartooth Mountains are clustered in three groups, topped by Granite Peak , Mount Wood 12,649 ft (3,855 m), and Castle Mountain 12,617 ft (3,846 m). The cluster containing Mount Wood is named the Granite Range . The largest of these three contiguous areas above 10,000 ft (3,000 m), which extends into Wyoming,
5217-610: The Bellies, and Beaver Dries its Fur. Formerly semi-nomad hunters and farmers in the northeastern woodland, they adapted to the nomadic lifestyle of the Plains Indians as hunters and gatherers, and hunted bison . Before 1700, they were using dog travois for carrying goods. From about 1730, the Plains tribes rapidly adopted the horse, which allowed them to move out on to the Plains and hunt buffalo more effectively. However,
5328-561: The Crow camp, reclining on his bed covered with robes, his face handsomely painted". Crow woman Pretty Shield remembered the sadness in camp. "We fasted, nearly starved in our sorrow for the loss of Long-Horse." Exposed to Sioux attacks, the Crows sided with the U.S. during the Great Sioux War in 1876–1877. On 10 April 1876, 23 Crow enlisted as Army scouts . They enlisted against a traditional Indian enemy, "... who were now in
5439-534: The Crow held a Sun Dance, attended by a poor Arapaho. A Crow with power gave him a medicine doll, and he quickly earned status and owned horses as no one else. During the next Sun Dance, some Crow stole back the figure to keep it in the tribe. Eventually the Arapaho made a duplicate. Later in life, he married a Kiowa woman and brought the doll with him. The Kiowas use it during the Sun Dance and recognize it as one of
5550-505: The Crow lived in the Yellowstone River valley, which extends from present-day Wyoming , through Montana and into North Dakota , where it joins the Missouri River . Since the 19th century, Crow people have been concentrated on their reservation established south of Billings, Montana . Today, they also live in several major, mainly western, cities. Tribal headquarters are located at Crow Agency, Montana . The tribe operates
5661-401: The Crow remained dominant in their established area through the 18th and 19th centuries, the era of the fur trade . Their historical territory stretched from what is now Yellowstone National Park and the headwaters of the Yellowstone River (E-chee-dick-karsh-ah-shay in Crow, translating to "Elk River") to the west, north to the Musselshell River , then northeast to the Yellowstone's mouth at
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#17327724837185772-658: The Crow split from the Hidatsa and moved westward. The Crow were largely pushed westward due to intrusion and influx of the Cheyenne and subsequently the Sioux , also known as the Lakota. To acquire control of their new territory, the Crow warred against Shoshone bands, such as the Bikkaashe, or "People of the Grass Lodges", and drove them westward. The Crow allied with local Kiowa and Plains Apache bands. The Kiowa and Plains Apache bands later migrated southward, and
5883-520: The Crows and the United States on 4 August. With the signing of the document, the Crows also recognized the supremacy of the United States, if they actually understood the word. River Crow chief Arapooish had left the treaty area in disgust. By help of the thunderbird he had to send a farewell shower down on the whites and the Mountain Crows. In 1829, seven Crow warriors were neutralized by Blood Blackfoot Indians led by Spotted Bear, who captured
5994-738: The Lakota Sioux and Cheyenne achieved a major victory over army forces under Lieutenant Colonel George Armstrong Custer at the Battle of the Little Big Horn in the Crow Indian Reservation , but the Great Sioux War (1876–1877) ended in the defeat of the Sioux and their Cheyenne allies. Crow warriors enlisted with the U.S. Army for this war. The Sioux and allies were forced from eastern Montana and Wyoming: some bands fled to Canada, while others suffered forced removal to distant reservations, primarily in present-day Montana and Nebraska west of
6105-490: The Lakota, as they sought to expel European Americans from the area. The Crow remained bitter enemies of both the Sioux and Cheyenne. They managed to retain a large reservation of more than 9300 km despite territorial losses, due in part to their cooperation with the federal government against their traditional enemies, the Sioux and Blackfoot. Many other tribes were forced onto much smaller reservations far from their traditional lands. The Crow were generally friendly with
6216-480: The Missouri River. In 1918, the Crow organized a gathering to display their culture, and they invited members of other tribes. The Crow Fair is now celebrated yearly on the third weekend of August, with wide participation from other tribes. A group of Crow went west after leaving the Hidatsa villages of earth lodges in the Knife River and Heart River area (present North Dakota) around 1675–1700. They selected
6327-403: The Missouri and "had little impact" on the tribe according to one source. The River Crows grew in number, when a group of Hidatsas joined them permanently to escape the scourge sweeping through the Hidatsa villages. Fort Van Buren was a short-lived trading post in existence from 1839 to 1842. It was built on the bank of the Yellowstone near the mouth of Tongue River. In the summer of 1840,
6438-570: The Sioux overpowered a barricaded war group of 30 Crow in the Big Dry area. The Crow were killed to either last or last but one man. Later, mourning Crow with "their hair cut off, their fingers and faces cut" brought the dead bodies back to camp. The drawing from the Sioux winter count of Lone Dog shows the Crow in the circle (the breastwork), while the Sioux close in on them. The many lines indicates flying bullets. The Sioux lost 14 warriors. Sioux chief Sitting Bull took part in this battle. In
6549-793: The Stillwater Complex) are 2.9-2.7 billion years old. In respect of their 'record of early crustal genesis and evolution', the International Union of Geological Sciences (IUGS) included the 'Archean Rocks of the Eastern Beartooth Mountains' in its assemblage of 100 'geological heritage sites' around the world in a listing published in October 2022. The organisation defines an IUGS Geological Heritage Site as 'a key place with geological elements and/or processes of international scientific relevance, used as
6660-575: The U.S. could not enforce respect for the treaty borders agreed upon 15 years before. The River Crow north of the Yellowstone developed a friendship with their former Gros Ventre enemies in the 1860s. A joint large-scale attack on a large Blackfoot camp at the Cypress Hills in 1866 resulted in a chaotic withdrawal of the Gros Ventres and Crow. The Blackfoot pursued the warriors for hours and killed allegedly more than 300. In 1868,
6771-486: The Yellowstone and the Bighorn. The Blood Blackfoot Bad Head's winter count tells about the early and persistent hostility between the Crow and the Blackfoot. In 1813, a force of Blood warriors set off for a raid on the Crow in the Bighorn area. Next year, Crows near Little Bighorn River killed Blackfoot Top Knot. A Crow camp neutralized thirty Cheyenne bent on capturing horses in 1819. The Cheyenne and warriors from
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#17327724837186882-541: The Yellowstone. The Sioux and their Indian allies, now formally at peace with the U.S., focused on intertribal wars at once. Raids against the Crows were "frequent, both by the Northern Cheyennes and by the Arapahos, as well as the Sioux, and by parties made up from all three tribes". Crow chief Plenty Coups recalled, "The three worst enemies our people had were combined against us …". In April 1870,
6993-482: The amphibolite or granulite facies. These form most of the exposed rock in Archean cratons. The granite-greenstone belts are intruded by a distinctive group of granitic rocks called the tonalite - trondhjemite - granodiorite or TTG suite. These are the most voluminous rocks in the craton and may represent an important early phase in the formation of continental crust. Mid-ocean ridges are where new oceanic crust
7104-404: The bands showing the colors of the minerals that formed them. Foliated rock often develops planes of cleavage . Slate is an example of a foliated metamorphic rock, originating from shale , and it typically shows well-developed cleavage that allows slate to be split into thin plates. The type of foliation that develops depends on the metamorphic grade. For instance, starting with a mudstone ,
7215-605: The bird this name was meant to refer to originally is lost to time, but many Apsáalooké people believe it references the mythical Thunderbird . The early home of the Crow Hidatsa ancestral tribe was near Lake Erie in what is now Ohio. Driven from there by better armed, aggressive neighbors, they briefly settled south of Lake Winnipeg in Manitoba . Later the people moved to the Devil's Lake region of North Dakota before
7326-410: The boundaries of a "Beartooth National Monument," but President Franklin D. Roosevelt never signed it. During the summer of 1960, The Wilderness Society organized an expedition into the Beartooths for Forest Service and National Park Service officials. Members of the expedition debated whether the mountains ought to be a wilderness area or a national park, but they reached no consensus and never made
7437-420: The bulk composition of a rock. Hot fluids circulating through pore space in the rock can dissolve existing minerals and precipitate new minerals. Dissolved substances are transported out of the rock by the fluids while new substances are brought in by fresh fluids. This can obviously change the mineral makeup of the rock. However, changes in the mineral composition can take place even when the bulk composition of
7548-399: The burning of coal seams. This produces a rock type named clinker . There is also a tendency for metasomatism between the igneous magma and sedimentary country rock, whereby the chemicals in each are exchanged or introduced into the other. In that case, hybrid rocks called skarn arise. Dynamic (cataclastic) metamorphism takes place locally along faults . Here intense shearing of
7659-435: The circulation of fluids through buried rock, to the list of processes that help bring about metamorphism. However, metamorphism can take place without metasomatism ( isochemical metamorphism ) or at depths of just a few hundred meters where pressures are relatively low (for example, in contact metamorphism ). Metamorphic processes change the texture or mineral composition of the metamorphosed rock. Metasomatism can change
7770-427: The collision of tectonic plates at convergent boundaries . Here formerly deeply buried rock has been brought to the surface by uplift and erosion. The metamorphic rock exposed in orogenic belts may have been metamorphosed simply by being at great depths below the Earth's surface, subjected to high temperatures and the great pressure caused by the immense weight of the rock layers above. This kind of regional metamorphism
7881-491: The contact area to unmetamorphosed (unchanged) country rock some distance away. The formation of important ore minerals may occur by the process of metasomatism at or near the contact zone. Contact aureoles around large plutons may be as much as several kilometers wide. The term hornfels is often used by geologists to signify those fine grained, compact, non-foliated products of contact metamorphism. The contact aureole typically shows little deformation, and so hornfels
7992-612: The crystal, producing a surface energy that makes the surface thermodynamically unstable. Recrystallization to coarser crystals reduces the surface area and so minimizes the surface energy. Although grain coarsening is a common result of metamorphism, rock that is intensely deformed may eliminate strain energy by recrystallizing as a fine-grained rock called mylonite . Certain kinds of rock, such as those rich in quartz, carbonate minerals , or olivine, are particularly prone to form mylonites, while feldspar and garnet are resistant to mylonitization. Many kinds of metamorphic rocks show
8103-537: The early 19th century, the Apsáalooke fell into three independent groupings, who came together only for common defense: Apsaalooke oral history describes a fourth group, the Bilapiluutche ("Beaver Dries its Fur"), who may have merged with the Kiowa in the second half of the 17th century. When European Americans arrived in numbers, the Crows were resisting pressure from enemies who greatly outnumbered them. In
8214-423: The eclogite facies releases a great deal of water vapor from the rock, which drives volcanism in the overlying volcanic arc . Eclogite is also significantly denser than blueschist, which drives further subduction of the slab deep into the Earth's mantle . Metabasalt and blueschist may be preserved in blueschist metamorphic belts formed by collisions between continents. They may also be preserved by obduction onto
8325-437: The following sequence develops with increasing temperature: The mudstone is first converted to slate, which is a very fine-grained, foliated metamorphic rock, characteristic of very low grade metamorphism. Slate in turn is converted to phyllite , which is fine-grained and found in areas of low grade metamorphism. Schist is medium to coarse-grained and found in areas of medium grade metamorphism. High-grade metamorphism transforms
8436-521: The fort in 1851. In 1851, the Crow, the Sioux, and six other Indian nations signed the Fort Laramie treaty along with the U.S. It should ensure peace forever between all nine partakers. Further, the treaty described the different tribal territories. The U.S. was allowed to construct roads and forts. A weak point in the treaty was the absence of rules to uphold the tribal borders. The Crow and various bands of Sioux attacked each other again from
8547-693: The high plains from the Black Hills of the Dakotas westward across the Powder River Basin to the crest of the Big Horn Mountains. Thereafter bands of Lakota Sioux led by Sitting Bull , Crazy Horse , Gall , and others, along with their Northern Cheyenne allies, hunted and raided throughout the length and breadth of eastern Montana and northeastern Wyoming , which had been for a time ancestral Crow territory. On 25 June 1876,
8658-548: The hunting lands of the Crow and warred against them. By right of conquest , they took over the eastern hunting lands of the Crow, including the Powder and Tongue River valleys, and pushed the less numerous Crow to the west and northwest upriver on the Yellowstone . After about 1860, the Lakota Sioux claimed all the former Crow lands from the Black Hills of South Dakota to the Big Horn Mountains of Montana. They demanded that
8769-449: The identical composition, Al 2 SiO 5 . Likewise, forsterite is stable over a broad range of pressure and temperature in marble , but is converted to pyroxene at elevated pressure and temperature in more silicate-rich rock containing plagioclase , with which the forsterite reacts chemically. Many complex high-temperature reactions may take place between minerals without them melting, and each mineral assemblage produced indicates
8880-676: The largest herds of bison and elk in North America. The Beartooth Mountains also have a very diverse range of trees, mostly conifers with stands of aspen and cottonwoods. The conifers mainly consist of Engelmann spruce , subalpine fir , whitebark pine , and lodgepole pine below 9,000 ft (2,700 m). Above 9,000 ft (2,700 m) there are few trees, the flora including grasses, wildflowers, and sagebrush . The Beartooth mountains are composed of Precambrian granite and crystalline metamorphic rocks dated at approximately 2.7 to 4 billion years old, making these rocks among
8991-437: The low-pressure facies, such as the hornfels and sanidinite facies . Most metamorphic rock is formed by regional metamorphism in the middle and lower crust, where the rock reaches the higher-pressure metamorphic facies. This rock is found at the surface only where extensive uplift and erosion has exhumed rock that was formerly much deeper in the crust. Metamorphic rock is extensively exposed in orogenic belts produced by
9102-453: The main limiting factors was the remoteness. Over time many of the mines ceased operations due to lack of funds or collapses that were not financially viable to correct. In 1989 Crown Butte Mines proposed massive additions to operations in the area. Once they began preparations for starting new mining operations, they came under public scrutiny based on the proximity to Yellowstone National Park and public fears that waste would find its way into
9213-611: The men in the fort fired a cannon, but no real harm came to anyone. The Crows left four days before the arrival of a Blackfeet band. The episode seems to be the worst armed conflict between the Crows and a group of whites until the Sword Bearer uprising in 1887. The death of chief Arapooish was recorded on 17 September 1834. The news reached Fort Clark at the Mandan village Mitutanka. Manager F.A. Chardon wrote he "was Killed by Black feet". The smallpox epidemic of 1837 spread along
9324-487: The mid-1850s. Soon, the Sioux took no notice of the 1851 borders and expanded into Crow territory west of the Powder. The Crows engaged in "… large-scale battles with invading Sioux …" near present-day Wyola, Montana . Around 1860, the western Powder area was lost. From 1857 to 1860, many Crow traded their surplus robes and skin at Fort Sarpy (II) near the mouth of the Bighorn River. During
9435-514: The mid-1860s, the Sioux resented the emigrant route Bozeman Trail through the Powder River bison habitat, although it mainly "crossed land guaranteed to the Crows". When the Army built forts to protect the trail, the Crow cooperated with the garrisons. On 21 December 1866, the Sioux, Cheyenne, and Arapaho defeated Captain William J. Fetterman and his men from Fort Phil Kearny . Evidently,
9546-426: The most powerful tribal medicines. They still credit the Crow tribe for the origin of their sacred Tai-may figure. The enmity between the Crow and the Lakota was reassured right from the start of the 19th century. The Crow killed a minimum of thirty Lakota in 1800–1801 according to two Lakota winter counts . The next year, the Lakota and their Cheyenne allies killed all the men in a Crow camp with thirty tipis. In
9657-486: The mountain range, the major expansion of mining began in 1882. Expansion continued adding more infrastructure for the mines. As growth continued there were six companies that had stakes in the New World Mining District . Between 1900-1955 the district has produced over 65,000 ozt (2,000 kg) of gold, 500,000 ozt (16,000 kg) of silver, and amounts of copper, zinc, and lead ore. One of
9768-543: The northern Plains tribes of the Flathead (although sometimes they had conflicts); Nez Perce , Kutenai , Shoshone, Kiowa , and Plains Apache . The powerful Iron Confederacy (Nehiyaw-Pwat), an alliance of northern plains Indian nations based around the fur trade, developed as enemies of the Crow. It was named after the dominating Plains Cree and Assiniboine peoples, and later included the Stoney , Saulteaux, and Métis . By
9879-488: The number of women and children taken captive to 160. By and by and with a fur trader as an intermediary, the Crows agreed to let 50 women return to their tribe. Fort Sarpy (I) near Rosebud River carried out trade with the Crow after the closing of Fort Alexander. River Crow went some times to the bigger Fort Union at the confluence of the Yellowstone and the Missouri. Both the "famous Absaroka amazon " Woman Chief and River Crow chief Twines His Tail (Rotten Tail) visited
9990-405: The old Crow country, menacing and often raiding the Crows in their reservation camps." Charles Varnum , leader of Custer's scouts, understood how valuable the enrolment of scouts from the local Indian tribe was. "These Crows were in their own country and knew it thoroughly." Metamorphic rock Metamorphic rocks arise from the transformation of existing rock to new types of rock in
10101-407: The oldest on Earth. The Stillwater igneous complex within the mountains is the location of the largest known deposits of platinum and chromium and the second largest deposits of nickel found in the United States. Older ages (4-3.2 billion years) are found in zircon crystals in meta-sedimentary rocks. The most abundant rocks in the Beartooths ( gneiss , amphibolites and granites, as well as
10212-460: The overriding plate as part of ophiolites . Eclogites are occasionally found at sites of continental collision, where the subducted rock is rapidly brought back to the surface, before it can be converted to the granulite facies in the hot upper mantle. Many samples of eclogite are xenoliths brought to the surface by volcanic activity. Many orogenic belts contain higher-temperature, lower-pressure metamorphic belts. These may form through heating of
10323-480: The park. In 1996 the federal government paid Crown Butte Mines $ 65 million to defray costs they had already paid; they had to pay $ 22.5 million to help repair the damage done to the surrounding environment. The Beartooth Mountains have been considered for inclusion in the national park system. In 1939, the director of the National Park Service drafted a presidential proclamation outlining
10434-481: The plains, and were still pressing hard on the Crows. Red Cloud's War (1866–1868) was a challenge by the Lakota Sioux to the United States military presence on the Bozeman Trail , a route along the eastern edge of the Big Horn Mountains to the Montana gold fields. Red Cloud's War ended with victory for the Lakota. The Treaty of Fort Laramie of 1868 with the United States confirmed the Lakota control over all
10545-840: The powerful Blackfoot , Gros Ventre , Assiniboine , Pawnee , and Ute . Later they had to face the Lakota and their allies, the Arapaho and Cheyenne , who also stole horses from their enemies. Their greatest enemies became the tribes of the Blackfoot Confederacy and the Lakota-Cheyenne-Arapaho alliance. In the 18th century, pressured by the Saulteaux and Cree peoples (the Iron Confederacy ), who had earlier and better access to guns through
10656-475: The rock by ascending magmas of volcanic arcs, but on a regional scale. Deformation and crustal thickening in an orogenic belt may also produce these kinds of metamorphic rocks. These rocks reach the greenschist , amphibolite, or granulite facies and are the most common of metamorphic rocks produced by regional metamorphosis. The association of an outer high-pressure, low-temperature metamorphic zone with an inner zone of low-pressure, high-temperature metamorphic rocks
10767-421: The rock does not change. This is possible because all minerals are stable only within certain limits of temperature, pressure, and chemical environment. For example, at atmospheric pressure, the mineral kyanite transforms to andalusite at a temperature of about 190 °C (374 °F). Andalusite, in turn, transforms to sillimanite when the temperature reaches about 800 °C (1,470 °F). All three have
10878-423: The rock to gneiss , which is coarse to very coarse-grained. Rocks that were subjected to uniform pressure from all sides, or those that lack minerals with distinctive growth habits, will not be foliated. Marble lacks platy minerals and is generally not foliated, which allows its use as a material for sculpture and architecture. Metamorphic rocks are one of the three great divisions of all rock types, and so there
10989-495: The rock typically forms mylonites. Impact metamorphism is unlike other forms of metamorphism in that it takes place during impact events by extraterrestrial bodies. It produces rare ultrahigh pressure metamorphic minerals, such as coesite and stishovite . Coesite is rarely found in eclogite brought to the surface in kimberlite pipes , but the presence of stishovite is unique to impact structures. Slate tiles are used in construction, particularly as roof shingle. Quartzite
11100-407: The rock underwent metamorphism. These minerals are known as index minerals . Examples include sillimanite , kyanite , staurolite , andalusite , and some garnet . Other minerals, such as olivines , pyroxenes , hornblende , micas , feldspars , and quartz , may be found in metamorphic rocks but are not necessarily the result of the process of metamorphism. These minerals can also form during
11211-486: The rock). Metasedimentary rocks are divided into carbonate-rich rock (metacarbonates or calcsilicate-rocks) or carbonate-poor rocks, and the latter are further classified by the relative abundance of mica in their composition. This ranges from low-mica psammite through semipelite to high-mica pelite . Psammites composed mostly of quartz are classified as quartzite. Metaigneous rocks are classified similarly to igneous rocks, by silica content, from meta-ultramafic-rock (which
11322-406: The sedimentary rock limestone and chalk change into larger crystals in the metamorphic rock marble . In metamorphosed sandstone, recrystallization of the original quartz sand grains results in very compact quartzite, also known as metaquartzite, in which the often larger quartz crystals are interlocked. Both high temperatures and pressures contribute to recrystallization. High temperatures allow
11433-580: The severe winters in the North kept their herds smaller than those of Plains tribes in the South. The Crow, Hidatsa, Eastern Shoshone , and Northern Shoshone soon became noted as horse breeders and dealers and developed relatively large horse herds. At the time, other eastern and northern tribes were also moving on to the Plains, in search of game for the fur trade, bison, and more horses. The Crow were subject to raids and horse thefts by horse-poor tribes, including
11544-581: The state. Crow Indians are a Plains tribe , who speak the Crow language , part of the Missouri River Valley branch of Siouan languages . Of the 14,000 enrolled tribal members, an estimated 3,000 spoke the Crow language in 2007. During the expansion into the West, the Crow people were allied with the United States against its neighbors and rivals, the Sioux and Cheyenne . In historical times,
11655-443: The summer of 1805, a Crow camp traded at the Hidatsa villages on Knife River in present North Dakota. Chiefs Red Calf and Spotted Crow allowed the fur trader Francois-Antoine Larocque to join it on its way across the plains to the Yellowstone area. He traveled with it to a point west of the place where Billings, Montana , is today. The camp crossed Little Missouri River and Bighorn River on the way. The next year, some Crow discovered
11766-485: The summer of 1870, some Sioux attacked a Crow reservation camp in the Bighorn/Little Bighorn area. The Crows reported Sioux Indians in the same area again in 1871. During the next years, this eastern part of the Crow reservation was taken over by the Sioux in search of buffalo. In August 1873, visiting Nez Percé and a Crow reservation camp at Pryor Creek further west faced a force of Sioux warriors in
11877-404: The temperatures and pressures at the time of metamorphism. These reactions are possible because of rapid diffusion of atoms at elevated temperature. Pore fluid between mineral grains can be an important medium through which atoms are exchanged. The change in the particle size of the rock during the process of metamorphism is called recrystallization . For instance, the small calcite crystals in
11988-451: The use of granulite as a classification for rock metamorphosed to the granulite facies. Instead, such rock will often be classified as a granofels. However, this approach is not universally accepted. Metamorphic rocks make up a large part of the Earth's crust and form 12% of the Earth's land surface. The lower continental crust is mostly metamafic-rock and pelite which have reached the granulite facies . The middle continental crust
12099-566: The zonal schemes, based on index minerals, that were pioneered by the British geologist, George Barrow . The metamorphic facies is not usually considered when classifying metamorphic rock based on protolith, mineral mode, or texture. However, a few metamorphic facies produce rock of such distinctive character that the facies name is used for the rock when more precise classification is not possible. The chief examples are amphibolite and eclogite . The British Geological Survey strongly discourages
12210-419: Was important in metamorphism. This hypothesis was tested by his friend, James Hall , who sealed chalk into a makeshift pressure vessel constructed from a cannon barrel and heated it in an iron foundry furnace. Hall found that this produced a material strongly resembling marble , rather than the usual quicklime produced by heating of chalk in the open air. French geologists subsequently added metasomatism ,
12321-488: Was killed in a suicidal attack on some Sioux, who previously had killed three soldiers from Camp Lewis on the upper Judith River (near Lewistown). George Bird Grinnell was a member of the exploring party in the Yellowstone National Park that year, and he saw the bringing in of the dead chief. A mule carried the body, which was wrapped in a green blanket. The chief was placed in a tipi "not far from
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