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102-705: The geology of the Rocky Mountains is that of a discontinuous series of mountain ranges with distinct geological origins. Collectively these make up the Rocky Mountains , a mountain system that stretches from Northern British Columbia through central New Mexico and which is part of the great mountain system known as the North American Cordillera . The rocky cores of the mountain ranges are, in most places, formed of pieces of continental crust that are over one billion years old. In

204-720: A gunman killed 10 people , including a police officer, in a King Soopers supermarket in Boulder . In an instance of anti-LGBT violence , a gunman killed 5 people at a nightclub in Colorado Springs during the night of November 19–20, 2022. Four warships of the U.S. Navy have been named the USS Colorado . The first USS Colorado was named for the Colorado River and served in the Civil War and later

306-414: A fairly steep angle, and a volcanic arc grows above the subducting plate. During the growth of the Rocky Mountains, the angle of the subducting plate may have been significantly flattened , moving the focus of melting and mountain building much farther inland than is normally expected. It is postulated that the shallow angle of the subducting plate greatly increased the friction and other interactions with

408-593: A hardwood floor: the rug bunches up and forms wrinkles (mountains). In Canada, the subduction of the Kula plate and the terranes smashing into the continent are the feet pushing the rug, the ancestral rocks are the rug, and the Canadian Shield in the middle of the continent is the hardwood floor. Farther south, the growth of the Rocky Mountains in the United States is a geological puzzle. Mountain building

510-676: A major industry in Colorado. This period became known locally as the Carnation Gold Rush . Poor labor conditions and discontent among miners resulted in several major clashes between strikers and the Colorado National Guard , including the 1903–1904 Western Federation of Miners Strike and Colorado Coalfield War , the latter of which included the Ludlow massacre that killed a dozen women and children. Both

612-653: A rapid decline in the organization's power, with membership waning significantly by the end of the 1920s. Colorado became the first western state to host a major political convention when the Democratic Party met in Denver in 1908. By the U.S. census in 1930 , the population of Colorado first exceeded one million residents. Colorado suffered greatly through the Great Depression and the Dust Bowl of

714-648: A significant portion of the extreme weather occurs in the least populated areas of the state. Thunderstorms are common east of the Continental Divide in the spring and summer, yet are usually brief. Hail is a common sight in the mountains east of the Divide and across the eastern Plains, especially the northeast part of the state. Hail is the most commonly reported warm-season severe weather hazard, and occasionally causes human injuries, as well as significant property damage. The eastern Plains are subject to some of

816-637: Is a state in the Western United States . It is one of the Mountain states , sharing the Four Corners region with Arizona , New Mexico , and Utah . It is also bordered by Wyoming to the north, Nebraska to the northeast, Kansas to the east, and Oklahoma to the southeast. Colorado is noted for its landscape of mountains , forests , high plains , mesas , canyons , plateaus , rivers , and desert lands. It encompasses most of

918-519: Is a mix of high plains, foothills, and mountains. Northwest and west Colorado are predominantly mountainous, with some desert lands mixed in. Southwest and southern Colorado are a complex mixture of desert and mountain areas. The climate of the Eastern Plains is semi-arid ( Köppen climate classification : BSk ) with low humidity and moderate precipitation, usually from 15 to 25 inches (380 to 640 millimeters) annually, although many areas near

1020-474: Is at work while the mountains are being uplifted until the mountains are reduced to low hills and plains. The early Cenozoic uplift of the Rocky Mountains of Colorado provides an example. As the uplift was occurring some 10,000 feet (3,000 m) of mostly Mesozoic sedimentary strata were removed by erosion over the core of the mountain range and spread as sand and clays across the Great Plains to

1122-841: Is drained by the Colorado River. The South Park of Colorado is the region of the headwaters of the South Platte River. In south-central Colorado is the large San Luis Valley , where the headwaters of the Rio Grande are located. The northern part of the valley is the San Luis Closed Basin , an endorheic basin that helped created the Great Sand Dunes . The valley sits between the Sangre de Cristo Mountains and San Juan Mountains . The Rio Grande drains due south into New Mexico, Texas, and Mexico. Across

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1224-623: Is flat and rolling land. East of the Rocky Mountains is the Colorado Eastern Plains of the High Plains , the section of the Great Plains within Colorado at elevations ranging from roughly 3,350 to 7,500 feet (1,020 to 2,290 m). The Colorado plains are mostly prairies but also include deciduous forests , buttes , and canyons. Precipitation averages 15 to 25 inches (380 to 640 mm) annually. Eastern Colorado

1326-544: Is generally accessed through artesian wells . Heavy usage of these wells for irrigation purposes caused underground water reserves to decline in the region. Eastern Colorado also hosts a considerable amount and range of livestock, such as cattle ranches and hog farms. Roughly 70% of Colorado's population resides along the eastern edge of the Rocky Mountains in the Front Range Urban Corridor between Cheyenne, Wyoming , and Pueblo, Colorado . This region

1428-773: Is higher than the high elevation points of 18 states and the District of Columbia. The Continental Divide of the Americas extends along the crest of the Rocky Mountains. The area of Colorado to the west of the Continental Divide is called the Western Slope of Colorado . West of the Continental Divide, water flows to the southwest via the Colorado River and the Green River towards the Gulf of California . Within

1530-471: Is known as "The Western Slope") are the cities of Grand Junction , Durango , and Montrose . Download coordinates as: To the west of the Great Plains of Colorado rises the eastern slope of the Rocky Mountains . Notable peaks of the Rocky Mountains include Longs Peak , Mount Blue Sky , Pikes Peak , and the Spanish Peaks near Walsenburg , in southern Colorado. This area drains to the east and

1632-466: Is more complex than states outside of the Mountain States region. Unlike most other states, southern Colorado is not always warmer than northern Colorado. Most of Colorado is made up of mountains, foothills, high plains, and desert lands. Mountains and surrounding valleys greatly affect the local climate. Northeast, east, and southeast Colorado are mostly the high plains, while Northern Colorado

1734-526: Is normally focused between 200 and 400 miles (300 and 600 km) inland from a subduction zone boundary. Geologists continue to gather evidence to explain the rise of the Rockies so much farther inland; the answer most likely lies with the unusual subduction of the Farallon plate , or possibly due to the subduction of an oceanic plateau . At a typical subduction zone, an oceanic plate typically sinks at

1836-467: Is partially protected from prevailing storms that blow in from the Pacific Ocean region by the high Rockies in the middle of Colorado. The "Front Range" includes Denver, Boulder , Fort Collins , Loveland, Castle Rock , Colorado Springs, Pueblo, Greeley, and other townships and municipalities in between. On the other side of the Rockies, the significant population centers in western Colorado (which

1938-559: Is presently mainly farmland and rangeland, along with small farming villages and towns. Corn , wheat , hay , soybeans , and oats are all typical crops. Most villages and towns in this region boast both a water tower and a grain elevator . Irrigation water is available from both surface and subterranean sources. Surface water sources include the South Platte , the Arkansas River , and a few other streams. Subterranean water

2040-464: Is the highest point in Colorado and the Rocky Mountains of North America. Colorado is the only U.S. state that lies entirely above 1,000 meters elevation. The point where the Arikaree River flows out of Yuma County, Colorado , and into Cheyenne County, Kansas , is the lowest in Colorado at 3,317 feet (1,011 m) elevation. This point, which is the highest low elevation point of any state,

2142-568: Is today the State of Colorado has been inhabited by Native Americans and their Paleoamerican ancestors for at least 13,500 years and possibly more than 37,000 years. The eastern edge of the Rocky Mountains was a major migration route that was important to the spread of early peoples throughout the Americas. The Lindenmeier site in Larimer County contains artifacts dating from approximately 8720 BCE. The Ancient Pueblo peoples lived in

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2244-432: Is very prone to droughts. Most of the precipitation comes from thunderstorms, which can be severe, and from major snowstorms that occur in the winter and early spring. Otherwise, winters tend to be mostly dry and cold. In much of the region, March is the snowiest month. April and May are normally the rainiest months, while April is the wettest month overall. The Front Range cities closer to the mountains tend to be warmer in

2346-578: The Adams-Onís Treaty of 1819. The treaty took effect on February 22, 1821. Having settled its border with Spain, the U.S. admitted the southeastern portion of the Territory of Missouri to the Union as the state of Missouri on August 10, 1821. The remainder of Missouri Territory, including what would become northeastern Colorado, became an unorganized territory and remained so for 33 years over

2448-787: The Alpide belt . The Pacific Ring of Fire includes the Andes of South America, extends through the North American Cordillera , the Aleutian Range , on through Kamchatka Peninsula , Japan , Taiwan , the Philippines , Papua New Guinea , to New Zealand . The Andes is 7,000 kilometres (4,350 mi) long and is often considered the world's longest mountain system. The Alpide belt stretches 15,000 km across southern Eurasia , from Java in Maritime Southeast Asia to

2550-551: The Annamite Range . If the definition of a mountain range is stretched to include underwater mountains, then the Ocean Ridge forms the longest continuous mountain system on Earth, with a length of 65,000 kilometres (40,400 mi). The position of mountain ranges influences climate, such as rain or snow. When air masses move up and over mountains, the air cools, producing orographic precipitation (rain or snow). As

2652-593: The Asiatic Squadron , where it was attacked during the 1871 Korean Expedition . The later three ships were named in honor of the state, including an armored cruiser and the battleship USS Colorado , the latter of which was the lead ship of her class and served in World War II in the Pacific beginning in 1941. At the time of the attack on Pearl Harbor , the battleship USS Colorado was located at

2754-835: The Bull Lake Glaciation that began about 150,000 years ago and the Pinedale Glaciation that probably remained at full glaciation until 15,000–20,000 years ago. Ninety percent of Yellowstone National Park was covered by ice during the Pinedale Glaciation. The little ice age was a period of glacial advance that lasted a few centuries from about 1550 to 1860. For example, the Agassiz and Jackson Glaciers in Glacier National Park reached their most forward positions about 1860 during

2856-843: The Cenozoic (66 million–1.8 million years ago) occurs in the San Juan Mountains and in other areas. Millennia of severe erosion in the Wyoming Basin transformed intermountain basins into a relatively flat terrain. The Tetons and other north-central ranges contain folded and faulted rocks of Paleozoic and Mesozoic age draped above cores of Proterozoic and Archean igneous and metamorphic rocks ranging in age from 1.2 billion (e.g., Tetons) to more than 3.3 billion years ( Beartooth Mountains ). Mountain range Mountain ranges are usually segmented by highlands or mountain passes and valleys . Individual mountains within

2958-701: The Colorado orogeny accreted to the Wyoming Craton along the Cheyenne belt , a 500-km-wide belt of Proterozoic rocks named for Cheyenne, Wyoming . As a result of the collision, older, Archean rocks of the Wyoming craton were intensely deformed and metamorphosed for at least 75 km inboard from the suture, which is marked today by the Laramie Mountains . The Colorado orogeny was likely part of

3060-756: The Cretaceous period when the western part of the Western Interior Seaway covered the region. Terranes started to collide with the western edge of North America in the Mississippian age (approximately 350 million years ago), causing the Antler orogeny . During the last half of the Mesozoic Era , much of today's California , British Columbia , Oregon , and Washington were added to North America . Western North America suffered

3162-561: The Great Lakes region to hunt across the High Plains of Colorado and Wyoming . The Spanish Empire claimed Colorado as part of Nuevo México . The U.S. acquired the territorial claim to the eastern Rocky Mountains with the Louisiana Purchase from France in 1803. This U.S. claim conflicted with the claim by Spain to the upper Arkansas River Basin . In 1806, Zebulon Pike led a U.S. Army reconnaissance expedition into

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3264-634: The Great Unconformity , from 1.1 billion to 510 million years ago. Twelve to 24 kilometers of basement rock eroded away. During the Paleozoic , western North America lay underneath a shallow sea, which deposited many kilometers of limestone and dolomite . In the southern Rocky Mountains, near present-day Colorado and New Mexico , the Precambrian and Paleozoic rocks were disturbed by mountain building approximately 300 Ma, during

3366-804: The Iberian Peninsula in Western Europe , including the ranges of the Himalayas , Karakoram , Hindu Kush , Alborz , Caucasus , and the Alps . The Himalayas contain the highest mountains in the world, including Mount Everest , which is 8,848 metres (29,029 ft) high. Mountain ranges outside these two systems include the Arctic Cordillera , Appalachians , Great Dividing Range , East Siberians , Altais , Scandinavians , Qinling , Western Ghats , Vindhyas , Byrrangas , and

3468-566: The Little Ice Age . All of the geological processes, above, have left a complex set of rocks exposed at the surface. For example, in the Rockies of Colorado, there is extensive granite and gneiss dating back to the Ancestral Rockies. In the central Canadian Rockies, the main ranges are composed of the Precambrian mudstones , while the front ranges are composed of the Paleozoic limestones and dolomites. Volcanic rock from

3570-729: The Mithrim Montes and Doom Mons on Titan, and Tenzing Montes and Hillary Montes on Pluto. Some terrestrial planets other than Earth also exhibit rocky mountain ranges, such as Maxwell Montes on Venus taller than any on Earth and Tartarus Montes on Mars . Jupiter's moon Io has mountain ranges formed from tectonic processes including the Boösaule , Dorian, Hi'iaka and Euboea Montes . Colorado Colorado ( / ˌ k ɒ l ə ˈ r æ d oʊ , - ˈ r ɑː d oʊ / KOL -ə- RAD -oh, -⁠ RAH -doh , other variants; Spanish: [koloˈɾaðo] )

3672-661: The Neoproterozoic . These deep extensional basement faults filled with sediments, such as the Uinta rift basin and were reactivated more recently in Earth history by orogenies. The Uinta Formation and Uncompahgre Formation are both examples of remnant Precambrian rift basin sediments. The end of the Neoproterozoic is not known from the rock record, indicating a period of long-running terrestrial erosion which produced by

3774-406: The Pennsylvanian . This mountain building produced the Ancestral Rocky Mountains . The uplift formed two large mountainous islands, known to geologists as Frontrangia and Uncompahgria , located roughly in the current locations of the Front Range and the San Juan Mountains . They consisted largely of Precambrian metamorphic rock , forced upward through layers of the limestone laid down in

3876-422: The Provisional Government of the Territory of Jefferson on August 24, 1859, but this new territory failed to secure approval from the Congress of the United States embroiled in the debate over slavery. The election of Abraham Lincoln for the President of the United States on November 6, 1860, led to the secession of nine southern slave states and the threat of civil war among the states . Seeking to augment

3978-503: The Rocky Mountains was a major migration route for early peoples who spread throughout the Americas. In 1848, much of the Nuevo México region was annexed to the United States with the Treaty of Guadalupe Hidalgo . The Pike's Peak Gold Rush of 1858–1862 created an influx of settlers. On February 28, 1861, U.S. President James Buchanan signed an act creating the Territory of Colorado , and on August 1, 1876, President Ulysses S. Grant signed Proclamation 230 , admitting Colorado to

4080-513: The Sangre de Cristo Range to the east of the San Luis Valley lies the Wet Mountain Valley . These basins, particularly the San Luis Valley, lie along the Rio Grande rift , a major geological formation of the Rocky Mountains, and its branches. The Western Slope of Colorado includes the western face of the Rocky Mountains and all of the area to the western border. This area includes several terrains and climates from alpine mountains to arid deserts. The Western Slope includes many ski resort towns in

4182-521: The Southern Rocky Mountains , as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains . Colorado is the eighth most extensive and 21st most populous U.S. state. The United States Census Bureau estimated the population of Colorado at 5,877,610 as of July 1, 2023, a 1.80% increase since the 2020 United States census. The region has been inhabited by Native Americans and their ancestors for at least 13,500 years and possibly much longer. The eastern edge of

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4284-435: The Territory of New Mexico , and the Territory of Utah . On April 9, 1851, Hispano settlers from the area of Taos settled the village of San Luis , then in the New Mexico Territory , as Colorado's first permanent Euro-American settlement , further cementing the traditions of New Mexican cuisine and New Mexico music in the developing Southern Rocky Mountain Front . In 1854, Senator Stephen A. Douglas persuaded

4386-456: The U.S. Congress to divide the unorganized territory east of the Continental Divide into two new organized territories, the Territory of Kansas and the Territory of Nebraska , and an unorganized southern region known as the Indian Territory . Each new territory was to decide the fate of slavery within its boundaries, but this compromise merely served to fuel animosity between free soil and pro-slavery factions. The gold seekers organized

4488-428: The Union as the 38th state. The Spanish adjective "colorado" means "colored red" or "ruddy". Colorado is nicknamed the " Centennial State " because it became a state 100 years (and four weeks) after the signing of the United States Declaration of Independence . Denver is the capital, the most populous city , and the center of the Front Range Urban Corridor . Colorado Springs is the second most populous city of

4590-448: The Union cause. In 1862, a force of Texas cavalry invaded the Territory of New Mexico and captured Santa Fe on March 10. The object of this Western Campaign was to seize or disrupt Colorado and California's gold fields and seize Pacific Ocean ports for the Confederacy. A hastily organized force of Colorado volunteers force-marched from Denver City, Colorado Territory , to Glorieta Pass , New Mexico Territory, in an attempt to block

4692-432: The Ute Indian reservation in southwestern Colorado. The Ute people were removed from the San Juan Mountains the following year. The United States Congress passed an enabling act on March 3, 1875, specifying the requirements for the Territory of Colorado to become a state. On August 1, 1876 (four weeks after the Centennial of the United States ), U.S. President Ulysses S. Grant signed a proclamation admitting Colorado to

4794-488: The continental margin while others represent small isolated mid-oceanic islands. Magma generated above the subducting slab rose into the North American continental crust about 200 to 300 miles (300 to 500 km) inland. Great arc-shaped volcanic mountain ranges, known as the Sierran Arc , grew as lava and ash spewed out of dozens of individual volcanoes . Beneath the surface, great masses of molten rock were injected and hardened in place. For 270 million years,

4896-417: The free Territory of Colorado . The original boundaries of Colorado remain unchanged except for government survey amendments. In 1776, Spanish priest Silvestre Vélez de Escalante recorded that Native Americans in the area knew the river as el Rio Colorado for the red-brown silt that the river carried from the mountains. In 1859, a U.S. Army topographic expedition led by Captain John Macomb located

4998-404: The question of slavery . After 11 years of war, Spain finally recognized the independence of Mexico with the Treaty of Córdoba signed on August 24, 1821. Mexico eventually ratified the Adams–Onís Treaty in 1831. The Texian Revolt of 1835–36 fomented a dispute between the U.S. and Mexico which eventually erupted into the Mexican–American War in 1846. Mexico surrendered its northern territory to

5100-427: The 1913–1914 Coalfield War and the Denver streetcar strike of 1920 resulted in federal troops intervening to end the violence. In 1927, the 1927-28 Colorado coal strike occurred and was ultimately successful in winning a dollar a day increase in wages. During it however the Columbine Mine massacre resulted in six dead strikers following a confrontation with Colorado Rangers . In a separate incident in Trinidad

5202-404: The 1930s, but a major wave of immigration following World War II boosted Colorado's fortune. Tourism became a mainstay of the state economy, and high technology became an important economic engine. The United States Census Bureau estimated that the population of Colorado exceeded five million in 2009. On September 11, 1957, a plutonium fire occurred at the Rocky Flats Plant , which resulted in

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5304-464: The Colorado orogen in the Laramie and adjacent Medicine Bow Mountains . Both the anorthosite and granite transect the Cheyenne belt in the Laramide Mountains, and intrude crystalline rocks of the Wyoming province. These intrusions comprise the northernmost segment of a wide belt of 1.4 Ga granitic intrusions that occur throughout the Colorado orogen. The breakup of the Rodinia supercontinent produced rifts between 900 million and 600 million years ago in

5406-399: The Green River briefly crosses over into Colorado. The Western Slope of Colorado is drained by the Colorado River and its tributaries (primarily the Gunnison River , Green River , and the San Juan River ). The Colorado River flows through Glenwood Canyon , and then through an arid valley made up of desert from Rifle to Parachute , through the desert canyon of De Beque Canyon , and into

5508-409: The Rocky Mountains and towns west to Utah. It is less populous than the Front Range but includes a large number of national parks and monuments. The northwestern corner of Colorado is a sparsely populated region, and it contains part of the noted Dinosaur National Monument , which not only is a paleontological area, but is also a scenic area of rocky hills, canyons, arid desert, and streambeds. Here,

5610-527: The Southwestern United States. In 1864, Territorial Governor John Evans appointed the Reverend John Chivington as Colonel of the Colorado Volunteers with orders to protect white settlers from Cheyenne and Arapaho warriors who were accused of stealing cattle. Colonel Chivington ordered his troops to attack a band of Cheyenne and Arapaho encamped along Sand Creek. Chivington reported that his troops killed more than 500 warriors. The militia returned to Denver City in triumph, but several officers reported that

5712-421: The Territory. The Union Pacific linked up with the Central Pacific Railroad at Promontory Summit, Utah , on May 10, 1869, to form the First transcontinental railroad . The Denver Pacific Railway reached Denver in June of the following year, and the Kansas Pacific arrived two months later to forge the second line across the continent. In 1872, rich veins of silver were discovered in the San Juan Mountains on

5814-466: The Texans. On March 28, the Coloradans and local New Mexico volunteers stopped the Texans at the Battle of Glorieta Pass , destroyed their cannon and supply wagons, and dispersed 500 of their horses and mules. The Texans were forced to retreat to Santa Fe. Having lost the supplies for their campaign and finding little support in New Mexico, the Texans abandoned Santa Fe and returned to San Antonio in defeat. The Confederacy made no further attempts to seize

5916-408: The U.S. with the Treaty of Guadalupe Hidalgo after the war in 1848; this included much of the western and southern areas of Colorado. Most American settlers first traveled to Colorado through the Santa Fe Trail , which connected the U.S. to Santa Fe and the Camino Real de Tierra Adentro southward. Others were traveling overland west to the Oregon Country , the new goldfields of California , or

6018-399: The Union as the 38th state and earning it the moniker "Centennial State". The discovery of a major silver lode near Leadville in 1878 triggered the Colorado Silver Boom . The Sherman Silver Purchase Act of 1890 invigorated silver mining, and Colorado's last, but greatest, gold strike at Cripple Creek a few months later lured a new generation of gold seekers. Colorado women were granted

6120-442: The Western Slope can be found at Colorado Mesa University in Grand Junction, Western Colorado University in Gunnison, Fort Lewis College in Durango, and Colorado Mountain College in Glenwood Springs and Steamboat Springs. The Four Corners Monument in the southwest corner of Colorado marks the common boundary of Colorado, New Mexico , Arizona , and Utah ; the only such place in the United States. The climate of Colorado

6222-447: The Western Slope. Grand Junction and Durango are the only major centers of television broadcasting west of the Continental Divide in Colorado, though most mountain resort communities publish daily newspapers. Grand Junction is located at the juncture of Interstate 70 and US 50, the only major highways in western Colorado. Grand Junction is also along the major railroad of the Western Slope, the Union Pacific . This railroad also provides

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6324-575: The air descends on the leeward side, it warms again (following the adiabatic lapse rate ) and is drier, having been stripped of much of its moisture. Often, a rain shadow will affect the leeward side of a range. As a consequence, large mountain ranges, such as the Andes, compartmentalize continents into distinct climate regions . Mountain ranges are constantly subjected to erosional forces which work to tear them down. The basins adjacent to an eroding mountain range are then filled with sediments that are buried and turned into sedimentary rock . Erosion

6426-499: The alpine snow melts by mid-August except for a few snow-capped peaks and a few small glaciers. The Colorado Mineral Belt , stretching from the San Juan Mountains in the southwest to Boulder and Central City on the front range, contains most of the historic gold- and silver-mining districts of Colorado. The 30 highest major summits of the Rocky Mountains of North America are all within the state. The summit of Mount Elbert at 14,437.6 feet (4,400.58 m) elevation in Lake County

6528-403: The arid desert of Grand Valley , where the city of Grand Junction is located. Also prominent is the Grand Mesa , which lies to the southeast of Grand Junction; the high San Juan Mountains, a rugged mountain range; and to the north and west of the San Juan Mountains, the Colorado Plateau . Grand Junction, Colorado , at the confluence of the Colorado and Gunnison Rivers, is the largest city on

6630-432: The boundaries of the new Territory of Colorado exclusively by lines of latitude and longitude , stretching from 37°N to 41°N latitude, and from 102°02′48″W to 109°02′48″W longitude ( 25°W to 32°W from the Washington Meridian ). After 163 years of government surveys, the borders of Colorado were officially defined by 697 boundary markers and 697 straight boundary lines . Colorado, Wyoming , and Utah are

6732-413: The confluence of the Green River with the Grand River in what is now Canyonlands National Park in Utah . The Macomb party designated the confluence as the source of the Colorado River. On April 12, 1861, South Carolina artillery opened fire on Fort Sumter to start the American Civil War . While many gold seekers held sympathies for the Confederacy , the vast majority remained fiercely loyal to

6834-409: The disputed region. Colonel Pike and his troops were arrested by Spanish cavalrymen in the San Luis Valley the following February, taken to Chihuahua , and expelled from Mexico the following July. The U.S. relinquished its claim to all land south and west of the Arkansas River and south of 42nd parallel north and west of the 100th meridian west as part of its purchase of Florida from Spain with

6936-485: The east. This mass of rock was removed as the range was actively undergoing uplift. The removal of such a mass from the core of the range most likely caused further uplift as the region adjusted isostatically in response to the removed weight. Rivers are traditionally believed to be the principal cause of mountain range erosion, by cutting into bedrock and transporting sediment. Computer simulation has shown that as mountain belts change from tectonically active to inactive,

7038-402: The effects of plate collisions were focused very near the edge of the North American Plate boundary, far to the west of the Rocky Mountain region. It was not until 80 MA that these effects began to reach the Rockies. The current Rocky Mountains were raised in the Laramide orogeny from between 80 and 55 Ma. For the Canadian Rockies, the mountain building is analogous to a rug being pushed on

7140-455: The effects of repeated collision as the Kula and Farallon Plates sank beneath the continental edge. Slivers of continental crust, carried along by subducting ocean plates, were swept into the subduction zone and scraped onto North America's western edge. These terranes represent a variety of tectonic environments. Some are ancient island arcs, similar to Japan, Indonesia and the Aleutians; others are fragments of oceanic crust obducted onto

7242-417: The entire Great Basin and all lands drained by the rivers Green , Grand , and Colorado . The federal government of the U.S. flatly refused to recognize the new Mormon government because it was theocratic and sanctioned plural marriage . Instead, the Compromise of 1850 divided the Mexican Cession and the northwestern claims of Texas into a new state and two new territories, the state of California ,

7344-570: The high rocks, revealing the ancestral rocks beneath, and forming the current landscape of the Rockies. Multiple periods of glaciation occurred during the Pleistocene Epoch (1.8 million–12,000 years ago), finally receding in the Holocene Epoch (fewer than 11,000 years ago). The ice ages left their mark on the Rockies, forming extensive glacial landforms, such as U-shaped valleys and cirques . Recent glacial episodes included

7446-483: The infamous Columbine High School massacre in 1999 which made international news, where two gunmen killed 12 students and one teacher, before committing suicide. The incident has spawned many copycat incidents . On July 20, 2012, a gunman killed 12 people in a movie theater in Aurora . The state responded with tighter restrictions on firearms, including introducing a limit on magazine capacity. On March 22, 2021,

7548-587: The interior of the Rocky Mountains are several large parks which are high broad basins. In the north, on the east side of the Continental Divide is the North Park of Colorado . The North Park is drained by the North Platte River , which flows north into Wyoming and Nebraska. Just to the south of North Park, but on the western side of the Continental Divide, is the Middle Park of Colorado , which

7650-687: The larger Yavapai orogeny , which extended across North America and probably to other continents that were joined to North America as part of the supercontinent , Columbia . In the Paleoproterozoic, terranes also accumulated on the west side of the Wyoming Craton, forming the Selway terrane in Idaho. Mesoproterozoic (~1.4 Ga) anorthosite and syenites of the Laramie Anorthosite Complex and granite intrude into rocks of

7752-628: The local and state Democrat and Republican parties , particularly in the governor's office and city governments of Denver, Cañon City , and Durango . A particularly strong element of the Klan controlled the Denver Police . Cross burnings became semi-regular occurrences in cities such as Florence and Pueblo. The Klan targeted African-Americans, Catholics , Eastern European immigrants, and other non-White Protestant groups. Efforts by non-Klan lawmen and lawyers including Philip Van Cise led to

7854-700: The mayor was accused of deputizing members of the KKK against the striking workers. More than 5,000 Colorado miners—many immigrants—are estimated to have died in accidents since records were first formally collected following an 1884 accident in Crested Butte that killed 59. In 1924, the Ku Klux Klan Colorado Realm achieved dominance in Colorado politics. With peak membership levels, the Second Klan levied significant control over both

7956-560: The midst and aftermath of the Civil War, many discouraged prospectors returned to their homes, but a few stayed and developed mines, mills, farms, ranches, roads, and towns in Colorado Territory. On September 14, 1864, James Huff discovered silver near Argentine Pass , the first of many silver strikes. In 1867, the Union Pacific Railroad laid its tracks west to Weir, now Julesburg , in the northeast corner of

8058-546: The modern range; they are now visible in many places throughout the Rockies, and are prominently shown along the Dakota Hogback , an early Cretaceous sandstone formation that runs along the eastern flank of the modern Rockies. Immediately after the Laramide orogeny, the Rockies were like Tibet : a high plateau, probably 6,000 metres (20,000 ft) above sea level. In the last 60 million years, erosion stripped away

8160-531: The naval base in San Diego, California, and thus went unscathed. The most recent vessel to bear the name USS Colorado is Virginia-class submarine USS Colorado (SSN-788) , which was commissioned in 2018. Colorado is notable for its diverse geography, which includes alpine mountains, high plains, deserts with huge sand dunes, and deep canyons. In 1861, the United States Congress defined

8262-901: The new Mormon settlements of the State of Deseret in the Salt Lake Valley , avoided the rugged Southern Rocky Mountains , and instead followed the North Platte River and Sweetwater River to South Pass (Wyoming) , the lowest crossing of the Continental Divide between the Southern Rocky Mountains and the Central Rocky Mountains. In 1849, the Mormons of the Salt Lake Valley organized the extralegal State of Deseret , claiming

8364-482: The only states that have their borders defined solely by straight boundary lines with no natural features. The southwest corner of Colorado is the Four Corners Monument at 36°59′56″N , 109°2′43″W . The Four Corners Monument , located at the place where Colorado, New Mexico , Arizona , and Utah meet, is the only place in the United States where four states meet. Approximately half of Colorado

8466-620: The plains and into the foothills, there is a wide variety of climate types. Locations merely a few miles apart can experience entirely different weather depending on the topography. Most valleys have a semi-arid climate, not unlike the eastern plains, which transitions to an alpine climate at the highest elevations. Microclimates also exist in local areas that run nearly the entire spectrum of climates, including subtropical highland ( Cfb/Cwb ), humid subtropical ( Cfa ), humid continental ( Dfa/Dfb ), Mediterranean ( Csa/Csb ) and subarctic ( Dfc ). Extreme weather changes are common in Colorado, although

8568-628: The political power of the Union states , the Republican Party -dominated Congress quickly admitted the eastern portion of the Territory of Kansas into the Union as the free State of Kansas on January 29, 1861, leaving the western portion of the Kansas Territory, and its gold-mining areas, as unorganized territory. Thirty days later on February 28, 1861, outgoing U.S. President James Buchanan signed an Act of Congress organizing

8670-444: The population of Colorado resides, lies in a pronounced precipitation shadow as a result of being on the lee side of the Rocky Mountains. In summer, this area can have many days above 95 °F (35 °C) and often 100 °F (38 °C). On the plains, the winter lows usually range from 25 to −10 °F (−4 to −23 °C). About 75% of the precipitation falls within the growing season, from April to September, but this area

8772-627: The rate of erosion drops because there are fewer abrasive particles in the water and fewer landslides. Mountains on other planets and natural satellites of the Solar System, including the Moon , are often isolated and formed mainly by processes such as impacts, though there are examples of mountain ranges (or "Montes") somewhat similar to those on Earth. Saturn 's moon Titan and Pluto , in particular, exhibit large mountain ranges in chains composed mainly of ices rather than rock. Examples include

8874-494: The right to vote on November 7, 1893, making Colorado the second state to grant universal suffrage and the first one by a popular vote (of Colorado men). The repeal of the Sherman Silver Purchase Act in 1893 led to a staggering collapse of the mining and agricultural economy of Colorado, but the state slowly and steadily recovered. Between the 1880s and 1930s, Denver's floriculture industry developed into

8976-405: The rivers are semi-humid climate. The area is known for its abundant sunshine and cool, clear nights, which give this area a great average diurnal temperature range . The difference between the highs of the days and the lows of the nights can be considerable as warmth dissipates to space during clear nights, the heat radiation not being trapped by clouds. The Front Range urban corridor, where most of

9078-479: The same mountain range do not necessarily have the same geologic structure or petrology . They may be a mix of different orogenic expressions and terranes , for example thrust sheets , uplifted blocks , fold mountains, and volcanic landforms resulting in a variety of rock types . Most geologically young mountain ranges on the Earth's land surface are associated with either the Pacific Ring of Fire or

9180-530: The shallow sea. The mountains eroded throughout the late Paleozoic and early Mesozoic , leaving extensive deposits of sedimentary rock . Mesozoic deposition in the Rockies occurred in a mix of marine, transitional, and continental environments as local relative sea levels changed. By the close of the Mesozoic , 10,000 to 15,000 feet (3000 to 4500 m) of sediment accumulated in 15 recognized formations . The most extensive non-marine formations were deposited in

9282-479: The significant plutonium contamination of surrounding populated areas. From the 1940s and 1970s, many protest movements gained momentum in Colorado, predominantly in Denver. This included the Chicano Movement , a civil rights , and social movement of Mexican Americans emphasizing a Chicano identity that is widely considered to have begun in Denver. The National Chicano Youth Liberation Conference

9384-483: The so-called battle was a blatant massacre of Indians at peace, that most of the dead were women and children, and that the bodies of the dead had been hideously mutilated and desecrated. Three U.S. Army inquiries condemned the action, and incoming President Andrew Johnson asked Governor Evans for his resignation, but none of the perpetrators was ever punished. This event is now known as the Sand Creek massacre . In

9486-411: The south, an older mountain range was formed 300 million years ago, then eroded away. The rocks of that older range were reformed into the Rocky Mountains. The Rocky Mountains took shape during an intense period of plate tectonic activity that resulted in much of the rugged landscape of western North America . The Laramide orogeny , about 80–55 million years ago, was the last of the three episodes and

9588-651: The southeast, ultimately either via the Mississippi River or the Rio Grande into the Gulf of Mexico . The Rocky Mountains within Colorado contain 53 true peaks and 58 named peaks that are 14,000 feet (4,267 m) or higher in elevation above sea level, known as fourteeners . These mountains are largely covered with trees such as conifers and aspens up to the tree line , at an elevation of about 12,000 feet (3,658 m) in southern Colorado to about 10,500 feet (3,200 m) in northern Colorado. Above this tree line, only alpine vegetation grows. Much of

9690-456: The state. Residents of the state are known as Coloradans , although the antiquated "Coloradoan" is occasionally used. Major parts of the economy include government and defense, mining, agriculture , tourism, and increasingly other kinds of manufacturing. With increasing temperatures and decreasing water availability, Colorado's agriculture forestry, and tourism economies are expected to be heavily affected by climate change . The region that

9792-481: The thick continental mass above it. Tremendous thrusts piled sheets of crust on top of each other, building the extraordinarily broad, high Rocky Mountain range. The current southern Rockies were forced upwards through the layers of Pennsylvanian and Permian sedimentary remnants of the Ancestral Rocky Mountains. Such sedimentary remnants were often tilted at steep angles along the flanks of

9894-505: The tracks for Amtrak 's California Zephyr passenger train, which crosses the Rocky Mountains between Denver and Grand Junction. The Western Slope includes multiple notable destinations in the Colorado Rocky Mountains, including Glenwood Springs , with its resort hot springs, and the ski resorts of Aspen , Breckenridge , Vail , Crested Butte , Steamboat Springs , and Telluride . Higher education in and near

9996-854: The valleys and mesas of the Colorado Plateau in far southwestern Colorado. The Ute Nation inhabited the mountain valleys of the Southern Rocky Mountains and the Western Rocky Mountains , even as far east as the Front Range of the present day. The Apache and the Comanche also inhabited the Eastern and Southeastern parts of the state. In the 17th century, the Arapaho and Cheyenne moved west from

10098-467: The winter due to Chinook winds which warms the area, sometimes bringing temperatures of 70 °F (21 °C) or higher in the winter. The average July temperature is 55 °F (13 °C) in the morning and 90 °F (32 °C) in the afternoon. The average January temperature is 18 °F (−8 °C) in the morning and 48 °F (9 °C) in the afternoon, although variation between consecutive days can be 40 °F (22 °C). Just west of

10200-490: Was held in Colorado in March 1969. In 1967, Colorado was the first state to loosen restrictions on abortion when governor John Love signed a law allowing abortions in cases of rape, incest, or threats to the woman's mental or physical health. Many states followed Colorado's lead in loosening abortion laws in the 1960s and 1970s. Since the late 1990s, Colorado has been the site of multiple major mass shootings , including

10302-481: Was modified by late Archean volcanic magmatism and plate movements and Proterozoic extension and rifting . The Wyoming Craton mainly consists of two rock units: granitoid plutons (2.8–2.55 Ga) and gneiss and migmatite . The granitoid rocks are mainly potassic granite and were derived principally from reworked older (3.1–2.8 Ga) gneiss. During the Paleoproterozoic , island-arc terrane associated with

10404-474: Was responsible for raising the Rocky Mountains. Subsequent erosion by glaciers has produced the current form of the mountains. The rocks in the Rocky Mountains were formed before the mountains were raised by tectonic forces. The oldest rock is Precambrian Wyoming craton that forms the core of the North American continent. The Wyoming Craton originated as a 100,000 km middle Archean craton that

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