Uranium is a chemical element with symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 electrons, of which 6 are valence electrons. Uranium is weakly radioactive because all isotopes of uranium are unstable, with half-lives varying between 159,200 years and 4.5 billion years. The most common isotopes in natural uranium are uranium-238 and uranium-235. Uranium has the highest atomic weight of the primordially occurring elements, its density is about 70% higher than that of lead, lower than that of gold or tungsten. It occurs in low concentrations of a few parts per million in soil and water, is commercially extracted from uranium-bearing minerals such as uraninite. In nature, uranium is found as uranium-238, uranium-235, a small amount of uranium-234. Uranium decays by emitting an alpha particle; the half-life of uranium-238 is about 4.47 billion years and that of uranium-235 is 704 million years, making them useful in dating the age of the Earth.
Many contemporary uses of uranium exploit its unique nuclear properties. Uranium-235 is the only occurring fissile isotope, which makes it used in nuclear power plants and nuclear weapons. However, because of the tiny amounts found in nature, uranium needs to undergo enrichment so that enough uranium-235 is present. Uranium-238 is fissionable by fast neutrons, is fertile, meaning it can be transmuted to fissile plutonium-239 in a nuclear reactor. Another fissile isotope, uranium-233, can be produced from natural thorium and is important in nuclear technology. Uranium-238 has a small probability for spontaneous fission or induced fission with fast neutrons. In sufficient concentration, these isotopes maintain a sustained nuclear chain reaction; this generates the heat in nuclear power reactors, produces the fissile material for nuclear weapons. Depleted uranium is used in kinetic energy penetrators and armor plating. Uranium is used as a colorant in uranium glass. Uranium glass fluoresces green in ultraviolet light.
It was used for tinting and shading in early photography. The 1789 discovery of uranium in the mineral pitchblende is credited to Martin Heinrich Klaproth, who named the new element after the discovered planet Uranus. Eugène-Melchior Péligot was the first person to isolate the metal and its radioactive properties were discovered in 1896 by Henri Becquerel. Research by Otto Hahn, Lise Meitner, Enrico Fermi and others, such as J. Robert Oppenheimer starting in 1934 led to its use as a fuel in the nuclear power industry and in Little Boy, the first nuclear weapon used in war. An ensuing arms race during the Cold War between the United States and the Soviet Union produced tens of thousands of nuclear weapons that used uranium metal and uranium-derived plutonium-239; the security of those weapons and their fissile material following the breakup of the Soviet Union in 1991 is an ongoing concern for public health and safety. See Nuclear proliferation; when refined, uranium is a weakly radioactive metal.
It has a Mohs hardness of 6, sufficient to scratch glass and equal to that of titanium, rhodium and niobium. It is malleable, ductile paramagnetic electropositive and a poor electrical conductor. Uranium metal has a high density of 19.1 g/cm3, denser than lead, but less dense than tungsten and gold. Uranium metal reacts with all non-metal elements and their compounds, with reactivity increasing with temperature. Hydrochloric and nitric acids dissolve uranium, but non-oxidizing acids other than hydrochloric acid attack the element slowly; when finely divided, it can react with cold water. Uranium in ores is extracted chemically and converted into uranium dioxide or other chemical forms usable in industry. Uranium-235 was the first isotope, found to be fissile. Other occurring isotopes are fissionable, but not fissile. On bombardment with slow neutrons, its uranium-235 isotope will most of the time divide into two smaller nuclei, releasing nuclear binding energy and more neutrons. If too many of these neutrons are absorbed by other uranium-235 nuclei, a nuclear chain reaction occurs that results in a burst of heat or an explosion.
In a nuclear reactor, such a chain reaction is slowed and controlled by a neutron poison, absorbing some of the free neutrons. Such neutron absorbent materials are part of reactor control rods; as little as 15 lb of uranium-235 can be used to make an atomic bomb. The first nuclear bomb used in war, Little Boy, relied on uranium fission, but the first nuclear explosive and the bomb that destroyed Nagasaki were both plutonium bombs. Uranium metal has three allotropic forms: α stable up to 668 °C. Orthorhombic, space group No. 63, lattice parameters a = 285.4 pm, b = 587 pm, c = 495.5 pm. Β stable from 668 °C to 775 °C. Tetragonal, space group P42/mnm, P42nm, or P4n2, lattice parameters a = 565.6 pm, b = c = 1075.9 pm. Γ from 775 °C to melting point—this is the most malleable and ductile state. Body-centered cubic, lattice parameter a = 352.4 pm. The major application of uranium in the military sector is
Wyoming is a state in the mountain region of the western United States. The state is the 10th largest by area, the least populous, the second most sparsely populated state in the country. Wyoming is bordered on the north by Montana, on the east by South Dakota and Nebraska, on the south by Colorado, on the southwest by Utah, on the west by Idaho and Montana; the state population was estimated at 577,737 in 2018, less than 31 of the most populous U. S. cities including Denver in neighboring Colorado. Cheyenne is the state capital and the most populous city, with an estimated population of 63,624 in 2017; the western two-thirds of the state is covered by the mountain ranges and rangelands of the Rocky Mountains, while the eastern third of the state is high elevation prairie called the High Plains. Half of the land in Wyoming is owned by the U. S. government, leading Wyoming to rank sixth by area and fifth by proportion of a state's land owned by the federal government. Federal lands include two national parks—Grand Teton and Yellowstone—two national recreation areas, two national monuments, several national forests, historic sites, fish hatcheries, wildlife refuges.
Original inhabitants of the region include the Crow, Arapaho and Shoshone. Southwestern Wyoming was in the Spanish Empire and Mexican territory until it was ceded to the United States in 1848 at the end of the Mexican–American War; the region acquired the name Wyoming when a bill was introduced to the U. S. Congress in 1865 to provide a "temporary government for the territory of Wyoming"; the name was used earlier for the Wyoming Valley in Pennsylvania, is derived from the Munsee word xwé:wamənk, meaning "at the big river flat". The main drivers of Wyoming's economy are mineral extraction—mostly coal, natural gas, trona—and tourism. Agricultural commodities include livestock, sugar beets and wool; the climate is semi-arid and continental and windier than the rest of the U. S. with greater temperature extremes. Wyoming has been a politically conservative state since the 1950s, with the Republican Party candidate winning every presidential election except 1964. Wyoming's climate is semi-arid and continental, is drier and windier in comparison to most of the United States with greater temperature extremes.
Much of this is due to the topography of the state. Summers in Wyoming are warm with July high temperatures averaging between 85 and 95 °F in most of the state. With increasing elevation, this average drops with locations above 9,000 feet averaging around 70 °F. Summer nights throughout the state are characterized by a rapid cooldown with the hottest locations averaging in the 50–60 °F range at night. In most of the state, most of the precipitation tends to fall in early summer. Winters are cold, but are variable with periods of sometimes extreme cold interspersed between mild periods, with Chinook winds providing unusually warm temperatures in some locations. Wyoming is a dry state with much of the land receiving less than 10 inches of rainfall per year. Precipitation depends on elevation with lower areas in the Big Horn Basin averaging 5–8 inches; the lower areas in the North and on the eastern plains average around 10–12 inches, making the climate there semi-arid. Some mountain areas do receive a good amount of precipitation, 20 inches or more, much of it as snow, sometimes 200 inches or more annually.
The state's highest recorded temperature is 114 °F at Basin on July 12, 1900 and the lowest recorded temperature is −66 °F at Riverside on February 9, 1933. The number of thunderstorm days vary across the state with the southeastern plains of the state having the most days of thunderstorm activity. Thunderstorm activity in the state is highest during early summer; the southeastern corner of the state is the most vulnerable part of the state to tornado activity. Moving away from that point and westwards, the incidence of tornadoes drops with the west part of the state showing little vulnerability. Tornadoes, where they occur, tend to be small and brief, unlike some of those that occur farther east; as specified in the designating legislation for the Territory of Wyoming, Wyoming's borders are lines of latitude 41°N and 45°N, longitude 104°3'W and 111°3'W, making the shape of the state a latitude-longitude quadrangle. Wyoming is one of only three states to have borders along only straight latitudinal and longitudinal lines, rather than being defined by natural landmarks.
Due to surveying inaccuracies during the 19th century, Wyoming's legal border deviates from the true latitude and longitude lines by up to half of a mile in some spots in the mountainous region along the 45th parallel. Wyoming is bordered on the north by Montana, on the east by South Dakota and Nebraska, on the south by Colorado, on the southwest by Utah, on the west by Idaho, it is the tenth largest state in the United States in total area, containing 97,814 square miles and is made up of 23 counties. From the north border to the south border it is 276 miles; the Great Plains meet the Rocky Mountains in Wyoming. The state is a great plateau broken by many mountain ranges. Surface elevations range from the summit of Gannett Peak in the Wind River Mountain Range, at 13,804 feet, to the Belle Fourche River val
The Ordovician is a geologic period and system, the second of six periods of the Paleozoic Era. The Ordovician spans 41.2 million years from the end of the Cambrian Period 485.4 million years ago to the start of the Silurian Period 443.8 Mya. The Ordovician, named after the Celtic tribe of the Ordovices, was defined by Charles Lapworth in 1879 to resolve a dispute between followers of Adam Sedgwick and Roderick Murchison, who were placing the same rock beds in northern Wales into the Cambrian and Silurian systems, respectively. Lapworth recognized that the fossil fauna in the disputed strata were different from those of either the Cambrian or the Silurian systems, placed them in a system of their own; the Ordovician received international approval in 1960, when it was adopted as an official period of the Paleozoic Era by the International Geological Congress. Life continued to flourish during the Ordovician as it did in the earlier Cambrian period, although the end of the period was marked by the Ordovician–Silurian extinction events.
Invertebrates, namely molluscs and arthropods, dominated the oceans. The Great Ordovician Biodiversification Event increased the diversity of life. Fish, the world's first true vertebrates, continued to evolve, those with jaws may have first appeared late in the period. Life had yet to diversify on land. About 100 times as many meteorites struck the Earth per year during the Ordovician compared with today; the Ordovician Period began with a major extinction called the Cambrian–Ordovician extinction event, about 485.4 Mya. It lasted for about 42 million years and ended with the Ordovician–Silurian extinction events, about 443.8 Mya which wiped out 60% of marine genera. The dates given are recent radiometric dates and vary from those found in other sources; this second period of the Paleozoic era created abundant fossils that became major petroleum and gas reservoirs. The boundary chosen for the beginning of both the Ordovician Period and the Tremadocian stage is significant, it correlates well with the occurrence of widespread graptolite and trilobite species.
The base of the Tremadocian allows scientists to relate these species not only to each other, but to species that occur with them in other areas. This makes it easier to place many more species in time relative to the beginning of the Ordovician Period. A number of regional terms have been used to subdivide the Ordovician Period. In 2008, the ICS erected a formal international system of subdivisions. There exist Baltoscandic, Siberian, North American, Chinese Mediterranean and North-Gondwanan regional stratigraphic schemes; the Ordovician Period in Britain was traditionally broken into Early and Late epochs. The corresponding rocks of the Ordovician System are referred to as coming from the Lower, Middle, or Upper part of the column; the faunal stages from youngest to oldest are: Late Ordovician Hirnantian/Gamach Rawtheyan/Richmond Cautleyan/Richmond Pusgillian/Maysville/Richmond Middle Ordovician Trenton Onnian/Maysville/Eden Actonian/Eden Marshbrookian/Sherman Longvillian/Sherman Soudleyan/Kirkfield Harnagian/Rockland Costonian/Black River Chazy Llandeilo Whiterock Llanvirn Early Ordovician Cassinian Arenig/Jefferson/Castleman Tremadoc/Deming/Gaconadian The Tremadoc corresponds to the Tremadocian.
The Floian corresponds to the lower Arenig. The Llanvirn occupies the rest of the Darriwilian, terminates with it at the base of the Late Ordovician; the Sandbian represents the first half of the Caradoc. During the Ordovician, the southern continents were collected into Gondwana. Gondwana started the period in equatorial latitudes and, as the period progressed, drifted toward the South Pole. Early in the Ordovician, the continents of Laurentia and Baltica were still independent continents, but Baltica began to move towards Laurentia in the period, causing the Iapetus Ocean between them to shrink; the small continent Avalonia separated from Gondwana and began to move north towards Baltica and Laurentia, opening the Rheic Ocean between Gondwana and Avalonia. The Taconic orogeny, a major mountain-building episode, was well under way in Cambrian times. In the early and middle Ordovician, temperatures were mild, but at the beginning of the Late Ordovician, from 460 to 450 Ma, volcanoes along the margin of the Iapetus Ocean spewed massive amounts of carbon dioxide, a greenhouse gas, into the atmosphere, turning the planet into a hothouse.
Sea levels were high, but as Gondwana moved south, ice accumulated into glaciers and sea levels dropped. At first, low-lying sea beds increased diversity, but glaciation led to mass extinctions as the seas drained and continental shelves became dry land. During the Ordovician, in fact during the Tremadocian, marine transgressions worldwide were the greatest for which evidence is preserved; these volcanic island arcs collided with proto North America to form the Appalachian mountains. By the end of the Late Ordovician the volcanic emissions had stopped. Gondwana had by that time neared the South Pole and was glaciated
The Bone Wars known as the Great Dinosaur Rush, was a period of intense and ruthlessly competitive fossil hunting and discovery during the Gilded Age of American history, marked by a heated rivalry between Edward Drinker Cope and Othniel Charles Marsh. Each of the two paleontologists used underhanded methods to try to outdo the other in the field, resorting to bribery and the destruction of bones; each scientist sought to ruin his rival's reputation and cut off his funding, using attacks in scientific publications. Their search for fossils led them west to rich bone beds in Colorado and Wyoming. From 1877 to 1892, both paleontologists used their wealth and influence to finance their own expeditions and to procure services and dinosaur bones from fossil hunters. By the end of the Bone Wars, both men had exhausted their funds in the pursuit of paleontological supremacy. Cope and Marsh were financially and ruined by their attempts to outcompete and disgrace each other, but they made important contributions to science and the field of paleontology, provided substantial material for further work—both scientists left behind many unopened boxes of fossils after their deaths.
The efforts of the two men led to more than 136 new species of dinosaurs being discovered and described. The products of the Bone Wars resulted in an increase in knowledge of prehistoric life, sparked the public's interest in dinosaurs, leading to continued fossil excavation in North America in the decades to follow. Many historical books and fictional adaptations have been published about this period of intense fossil-hunting activity. At first, the relationship between Cope and Marsh was amicable, they spent several days together. They named species after each other. Over time their relations due in part to their strong personalities. Cope possessed a quick temper. Both were distrustful, their differences extended into the scientific realm, as Cope was a firm supporter of Neo-Lamarckism while Marsh supported Charles Darwin's theory of evolution by natural selection. At the best of times, both men were inclined to look down on each other subtly; as one observer put it, "The patrician Edward may have considered Marsh not quite a gentleman.
The academic Othniel regarded Cope as not quite a professional."Cope and Marsh came from different backgrounds. Cope was born into a influential Quaker family based in Philadelphia. Although his father wanted his son to work as a farmer, Cope distinguished himself as a naturalist. In 1864 a member of the Academy of Natural Sciences, Cope became a professor of zoology at Haverford College and joined Ferdinand Hayden on his expeditions west. In contrast, Marsh would have grown up poor, the son of a struggling family in Lockport, New York, had it not been for the benefaction of his uncle, philanthropist George Peabody. Marsh persuaded his uncle to build the Peabody Museum of Natural History, placing Marsh as head of the museum. Combined with the inheritance he received from Peabody upon his death in 1869, Marsh was financially comfortable. On one occasion, the two scientists had gone on a fossil-collecting expedition to Cope's marl pits in New Jersey, where William Parker Foulke had discovered the holotype specimen of Hadrosaurus foulkii, described by the paleontologist Joseph Leidy.
Though the two parted amicably, Marsh secretly bribed the pit operators to divert future fossil finds to him, instead of Cope. The two began attacking each other in papers and publications, their personal relations deteriorated. Marsh humiliated Cope by pointing out that his reconstruction of the plesiosaur Elasmosaurus was flawed, with the head placed where the tail should have been. Cope, in turn, began collecting in what Marsh considered his private bone-hunting turf in Kansas and Wyoming, further damaging their relationship. In the 1870s, Cope's and Marsh's professional attentions were directed to the American West by word of large fossil finds. Using his influence in Washington, D. C. Cope was granted a position on the U. S. Geological Survey under Ferdinand Hayden. While the position offered no salary, it afforded Cope a great opportunity to collect fossils in the West and publish his finds. Cope's flair for dramatic writing suited Hayden, who needed to make a popular impression with the official survey reports.
In June 1872 Cope set off on his first trip, intending to observe the Eocene bone beds of Wyoming for himself. This caused a rift between Cope and Leidy, it was Leidy who had enjoyed receiving many of the fossils from Hayden's collection until Cope joined the survey, now Cope was hunting for fossils in Leidy's staked territory—at the same time Leidy was to be collecting. Hayden attempted to smooth things over with Leidy in a letter: I asked him not to go into that field, that you were going there, he laughed at the idea of being restricted to any locality and said he intended to go whether I aided him or not. I was anxious to secure the cooperation of such a worker as an honor to my corps. I could not be responsible for the field he selected in as much as I pay him no salary and a portion of his expenses. You will see therefore that while it is not a pleasant thing to work in competition with others it seems a
A geologist is a scientist who studies the solid and gaseous matter that constitutes the Earth and other terrestrial planets, as well as the processes that shape them. Geologists study geology, although backgrounds in physics, chemistry and other sciences are useful. Field work is an important component of geology, although many subdisciplines incorporate laboratory work. Geologists work in the energy and mining sectors searching for natural resources such as petroleum, natural gas and base metals, they are in the forefront of preventing and mitigating damage from natural hazards and disasters such as earthquakes, volcanoes and landslides. Their studies are used to warn the general public of the occurrence of these events. Geologists are important contributors to climate change discussions. James Hutton is viewed as the first modern geologist. In 1785 he presented a paper entitled Theory of the Earth to the Royal Society of Edinburgh. In his paper, he explained his theory that the Earth must be much older than had been supposed to allow enough time for mountains to be eroded and for sediments to form new rocks at the bottom of the sea, which in turn were raised up to become dry land.
Hutton published a two-volume version of his ideas in 1795. Followers of Hutton were known as Plutonists because they believed that some rocks were formed by vulcanism, the deposition of lava from volcanoes, as opposed to the Neptunists, led by Abraham Werner, who believed that all rocks had settled out of a large ocean whose level dropped over time; the first geological map of the United States was produced in 1809 by William Maclure. In 1807, Maclure commenced the self-imposed task of making a geological survey of the United States; every state in the Union was traversed and mapped by him. The results of his unaided labors were submitted to the American Philosophical Society in a memoir entitled Observations on the Geology of the United States explanatory of a Geological Map, published in the Society's Transactions, together with the nation's first geological map; this antedates William Smith's geological map of England by six years, although it was constructed using a different classification of rocks.
Sir Charles Lyell first published his famous book, Principles of Geology, in 1830. This book, which influenced the thought of Charles Darwin promoted the doctrine of uniformitarianism; this theory states that slow geological processes have occurred throughout the Earth's history and are still occurring today. In contrast, catastrophism is the theory that Earth's features formed in single, catastrophic events and remained unchanged thereafter. Though Hutton believed in uniformitarianism, the idea was not accepted at the time. For an aspiring geologist, training includes significant coursework in physics and chemistry, in addition to classes offered through the geology department. Most geologists need skills in GIS and other mapping techniques. Geology students spend portions of the year the summer though sometimes during a January term and working under field conditions with faculty members. Many non-geologists take geology courses or have expertise in geology that they find valuable to their fields.
Geologists may concentrate their studies or research in one or more of the following disciplines: Economic geology: the study of ore genesis, the mechanisms of ore creation, geostatistics. Engineering geology: application of the geologic sciences to engineering practice for the purpose of assuring that the geologic factors affecting the location, construction and maintenance of engineering works are recognized and adequately provided for. Geochemistry: the applied branch deals with the study of the chemical makeup and behaviour of rocks, the study of the behaviour of their minerals. Geochronology: the study of isotope geology toward determining the date within the past of rock formation, metamorphism and geological events. Geomorphology: the study of landforms and the processes that create them Hydrogeology: the study of the origin and movement of groundwater water in a subsurface geological system. Igneous petrology: the study of igneous processes such as igneous differentiation, fractional crystallization and volcanological phenomena.
Isotope geology: the case of the isotopic composition of rocks to determine the processes of rock and planetary formation. Metamorphic petrology: the study of the effects of metamorphism on minerals and rocks. Marine geology: the study of the seafloor. Marine geology has strong ties to physical plate tectonics. Palaeoclimatology: the application of geological science to determine the climatic conditions present in the Earth's atmosphere within the Earth's history. Palaeontology: the classification and taxonomy of fossils within the geological record and the construction of a palaeontological history of the Earth. Pe
Montana is a landlocked state in the Northwestern United States. Montana has several nicknames, although none are official, including "Big Sky Country" and "The Treasure State", slogans that include "Land of the Shining Mountains" and more "The Last Best Place". Montana is the 4th largest in area, the 8th least populous, the 3rd least densely populated of the 50 U. S. states. The western half of Montana contains numerous mountain ranges. Smaller island ranges are found throughout the state. In all, 77 named; the eastern half of Montana is characterized by badlands. Montana is bordered by Idaho to the west, Wyoming to the south, North Dakota and South Dakota to the east, the Canadian provinces of British Columbia and Saskatchewan to the north; the economy is based on agriculture, including ranching and cereal grain farming. Other significant economic resources include oil, coal, hard rock mining, lumber; the health care and government sectors are significant to the state's economy. The state's fastest-growing sector is tourism.
Nearly 13 million tourists annually visit Glacier National Park, Yellowstone National Park, the Beartooth Highway, Flathead Lake, Big Sky Resort, other attractions. The name Montana comes from the Spanish word Montaña, which in turn comes from the Latin word Montanea, meaning "mountain", or more broadly, "mountainous country". Montaña del Norte was the name given by early Spanish explorers to the entire mountainous region of the west; the name Montana was added to a bill by the United States House Committee on Territories, chaired at the time by Rep. James Ashley of Ohio, for the territory that would become Idaho Territory; the name was changed by Representatives Henry Wilson and Benjamin F. Harding, who complained Montana had "no meaning"; when Ashley presented a bill to establish a temporary government in 1864 for a new territory to be carved out of Idaho, he again chose Montana Territory. This time Rep. Samuel Cox of Ohio, objected to the name. Cox complained the name was a misnomer given most of the territory was not mountainous and that a Native American name would be more appropriate than a Spanish one.
Other names such as Shoshone were suggested, but it was decided the Committee on Territories could name it whatever they wanted, so the original name of Montana was adopted. Montana is one of the nine Mountain States, located in the north of the region known as the Western United States, it borders North South Dakota to the east. Wyoming is to the south, Idaho is to the west and southwest, three Canadian provinces, British Columbia and Saskatchewan, are to the north. With an area of 147,040 square miles, Montana is larger than Japan, it is the fourth largest state in the United States after Alaska and California. S. state. The state's topography is defined by the Continental Divide, which splits much of the state into distinct eastern and western regions. Most of Montana's 100 or more named mountain ranges are in the state's western half, most of, geologically and geographically part of the Northern Rocky Mountains; the Absaroka and Beartooth ranges in the state's south-central part are technically part of the Central Rocky Mountains.
The Rocky Mountain Front is a significant feature in the state's north-central portion, isolated island ranges that interrupt the prairie landscape common in the central and eastern parts of the state. About 60 percent of the state is part of the northern Great Plains; the Bitterroot Mountains—one of the longest continuous ranges in the Rocky Mountain chain from Alaska to Mexico—along with smaller ranges, including the Coeur d'Alene Mountains and the Cabinet Mountains, divide the state from Idaho. The southern third of the Bitterroot range blends into the Continental Divide. Other major mountain ranges west of the Divide include the Cabinet Mountains, the Anaconda Range, the Missions, the Garnet Range, Sapphire Mountains, Flint Creek Range; the Divide's northern section, where the mountains give way to prairie, is part of the Rocky Mountain Front. The front is most pronounced in the Lewis Range, located in Glacier National Park. Due to the configuration of mountain ranges in Glacier National Park, the Northern Divide crosses this region and turns east in Montana at Triple Divide Peak.
It causes the Waterton River and Saint Mary rivers to flow north into Alberta, Canada. There they join the Saskatchewan River, which empties into Hudson Bay. East of the divide, several parallel ranges cover the state's southern part, including the Gravelly Range, the Madison Range, Gallatin Range, Absaroka Mountains and the Beartooth Mountains; the Beartooth Plateau is the largest continuous land mass over 10,000 feet high in the continental United States. It contains Granite Peak, 12,799 feet high. North of these ranges are the Big Belt Mountains, Bridger Mountains, Tobacco Roots, several island ranges, including the Crazy Mountains and Little Belt Mountains. Between many mountain ranges are rich river valleys; the Big Hole Valley, Bitterroot Valley, Gallatin Valley, Flathead Valley, Paradise Valley have extensive agricultural resources and multiple opportunities for tourism and recreation. East and north of this transition zone are the expansive and sparsely populated Northern Plains, with tableland prairies, smaller island mountain ranges, badlands.
The isolated island ranges east of the Divide include the Bear Paw Mountains, Bull Mountains, Castle Mountains, Crazy Mountains, Highwood Mountains, Judi
Utah is a state in the western United States. It became the 45th state admitted to the U. S. on January 4, 1896. Utah is the 13th-largest by area, 31st-most-populous, 10th-least-densely populated of the 50 United States. Utah has a population of more than 3 million according to the Census estimate for July 1, 2016. Urban development is concentrated in two areas: the Wasatch Front in the north-central part of the state, which contains 2.5 million people. Utah is bordered by Colorado to the east, Wyoming to the northeast, Idaho to the north, Arizona to the south, Nevada to the west, it touches a corner of New Mexico in the southeast. 62% of Utahns are reported to be members of The Church of Jesus Christ of Latter-day Saints, making Utah the only state with a majority population belonging to a single church. This influences Utahn culture and daily life; the LDS Church's world headquarters is located in Salt Lake City. The state is a center of transportation, information technology and research, government services, a major tourist destination for outdoor recreation.
In 2013, the U. S. Census Bureau estimated. St. George was the fastest-growing metropolitan area in the United States from 2000 to 2005. Utah has the 14th highest median average income and the least income inequality of any U. S. state. A 2012 Gallup national survey found Utah overall to be the "best state to live in" based on 13 forward-looking measurements including various economic and health-related outlook metrics. A common folk etymology is that the name "Utah" is derived from the name of the Ute tribe, purported to mean "people of the mountains" in the Ute language. However, the word for people in Ute is'núuchiu' while the word for mountain is'káav', offering no linguistic connection to the words'Ute' or'Utah'. According to other sources "Utah" is derived from the Apache name "yuttahih" which means "One, Higher up" or "Those that are higher up". In the Spanish language it was said as "Yuta", subsequently the English-speaking people adapted the word "Utah". Thousands of years before the arrival of European explorers, the Ancestral Puebloans and the Fremont people lived in what is now known as Utah, some of which spoke languages of the Uto-Aztecan group.
Ancestral Pueblo peoples built their homes through excavations in mountains, the Fremont people built houses of straw before disappearing from the region around the 15th century. Another group of Native Americans, the Navajo, settled in the region around the 18th century. In the mid-18th century, other Uto-Aztecan tribes, including the Goshute, the Paiute, the Shoshone, the Ute people settled in the region; these five groups were present. The southern Utah region was explored by the Spanish in 1540, led by Francisco Vásquez de Coronado, while looking for the legendary Cíbola. A group led by two Catholic priests—sometimes called the Dominguez-Escalante Expedition—left Santa Fe in 1776, hoping to find a route to the coast of California; the expedition encountered the native residents. The Spanish made further explorations in the region, but were not interested in colonizing the area because of its desert nature. In 1821, the year Mexico achieved its independence from Spain, the region became known as part of its territory of Alta California.
European trappers and fur traders explored some areas of Utah in the early 19th century from Canada and the United States. The city of Provo, Utah was named for one, Étienne Provost, who visited the area in 1825; the city of Ogden, Utah was named after Peter Skene Ogden, a Canadian explorer who traded furs in the Weber Valley. In late 1824, Jim Bridger became the first known English-speaking person to sight the Great Salt Lake. Due to the high salinity of its waters, He thought. After the discovery of the lake, hundreds of American and Canadian traders and trappers established trading posts in the region. In the 1830s, thousands of migrants traveling from the Eastern United States to the American West began to make stops in the region of the Great Salt Lake known as Lake Youta. Following the death of Joseph Smith in 1844, Brigham Young, as president of the Quorum of the Twelve, became the effective leader of the LDS Church in Nauvoo, Illinois. To address the growing conflicts between his people and their neighbors, Young agreed with Illinois Governor Thomas Ford in October 1845 that the Mormons would leave by the following year.
Young and the first band of Mormon pioneers reached the Salt Lake Valley on July 24, 1847. Over the next 22 years, more than 70,000 pioneers settled in Utah. For the first few years, Brigham Young and the thousands of early settlers of Salt Lake City struggled to survive; the arid desert land was deemed by the Mormons as desirable as a place where they could practice their religion without harassment. The Mormon settlements provided pioneers for other settlements in the West. Salt Lake City became the hub of a "far-flung commonwealth" of Mormon settlements. With new church converts coming from the East and around the world, Church leaders assigned groups of church members as missionaries to establish other settlements throughout the West, they developed irrigation to support large pioneer populations along Utah's Wasatch front. Throughout the remainder of the 19th century, Mormon pioneers established hundreds of other settlements in Utah, Id