The Rocky Mountains known as the Rockies, are a major mountain range in western North America. The Rocky Mountains stretch more than 4,800 kilometers from the northernmost part of British Columbia, in western Canada, to New Mexico in the Southwestern United States. Located within the North American Cordillera, the Rockies are somewhat distinct from the Pacific Coast Ranges, Cascade Range, the Sierra Nevada, which all lie farther to the west; the Rocky Mountains formed 80 million to 55 million years ago during the Laramide orogeny, in which a number of plates began sliding underneath the North American plate. The angle of subduction was shallow, resulting in a broad belt of mountains running down western North America. Since further tectonic activity and erosion by glaciers have sculpted the Rockies into dramatic peaks and valleys. At the end of the last ice age, humans began inhabiting the mountain range. After Europeans, such as Sir Alexander Mackenzie, Americans, such as the Lewis and Clark expedition, began exploring the range and furs drove the initial economic exploitation of the mountains, although the range itself never experienced dense population.
Public parks and forest lands protect much of the mountain range, they are popular tourist destinations for hiking, mountaineering, hunting, mountain biking and snowboarding. The name of the mountains is a translation of an Amerindian name, related to Algonquian; the first mention of their present name by a European was in the journal of Jacques Legardeur de Saint-Pierre in 1752, where they were called "Montagnes de Roche". The Rocky Mountains are defined as stretching from the Liard River in British Columbia south to the Rio Grande in New Mexico; the Rockies vary in width from 110 to 480 kilometres. The Rocky Mountains are notable for containing the highest peaks in central North America; the range's highest peak is Mount Elbert located in Colorado at 4,401 metres above sea level. Mount Robson in British Columbia, at 3,954 metres, is the highest peak in the Canadian Rockies; the eastern edge of the Rockies rises above the Interior Plains of central North America, including the Sangre de Cristo Mountains of New Mexico and Colorado, the Front Range of Colorado, the Wind River Range and Big Horn Mountains of Wyoming, the Absaroka-Beartooth ranges and Rocky Mountain Front of Montana and the Clark Range of Alberta.
The western edge of the Rockies includes ranges such as the Wasatch near Salt Lake City and the Bitterroots along the Idaho-Montana border. The Great Basin and Columbia River Plateau separate these subranges from distinct ranges further to the west. In Canada, the western edge of the Rockies is formed by the huge Rocky Mountain Trench, which runs the length of British Columbia from its beginnings in the middle Flathead River valley in western Montana to the south bank of the Liard River. Geographers define three main groups of the Canadian Rockies: the Continental Ranges, Hart Ranges, Muskwa Ranges; the Rockies do not extend into central British Columbia. Other mountain ranges continue beyond the Liard River, including the Selwyn Mountains in Yukon, the Brooks Range in Alaska, but those are not part of the Rockies, though they are part of the American Cordillera; the Continental Divide of the Americas is located in the Rocky Mountains and designates the line at which waters flow either to the Atlantic or Pacific Oceans.
Triple Divide Peak in Glacier National Park is so named because water falling on the mountain reaches not only the Atlantic and Pacific but Hudson Bay as well. Farther north in Alberta, the Athabasca and other rivers feed the basin of the Mackenzie River, which has its outlet on the Beaufort Sea of the Arctic Ocean. Human population is not dense in the Rocky Mountains, with an average of four people per square kilometer and few cities with over 50,000 people. However, the human population grew in the Rocky Mountain states between 1950 and 1990; the forty-year statewide increases in population range from 35% in Montana to about 150% in Utah and Colorado. The populations of several mountain towns and communities have doubled in the last forty years. Jackson, increased 260%, from 1,244 to 4,472 residents, in forty years; the rocks in the Rocky Mountains were formed. The oldest rock is Precambrian metamorphic rock. There is Precambrian sedimentary argillite, dating back to 1.7 billion years ago. 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, these ancestral rocks were disturbed by mountain building 300 Ma, during the Pennsylvanian. This mountain-building produced the Ancestral Rocky Mountains, they consisted of Precambrian metamorphic rock forced upward through layers of the limestone laid down in the shallow sea. The mountains eroded throughout the late Paleozoic and early Mesozoic, leaving extensive deposits of sedimentary rock. Terranes began colliding with the western edge of North America in the Mississippian, causing the Antler orogeny. For 270 million years, the focus of the effects of plate collisions were near the edge of the North American plate boundary, far to the west of the Rocky Mountain region, it was. The current Rocky Mountains arose in the Laramide orogeny from between 55 Ma. For the Canadi
Gore Canyon is a short isolated canyon on the upper Colorado River in southwestern Grand County, Colorado in the United States. The steep and rugged canyon 3 miles long, was carved by the river as it passed the northern end of the Gore Range southwest of Kremmling; the Colorado descends from 7,300 ft to 7,000 ft over the length of the canyon. The steep walls ascend 1,000 ft on either side; the canyon marks the southwestern end of the Middle Park basin in north central Colorado. The canyon is roadless and inaccessible by most traffic, except for the Union Pacific Railroad's Moffat Subdivision and whitewater boats. Despite the short length, the canyon presented a formidable obstacle for the railroad, the building of the line through it was considered a monumental engineering achievement in its day. Although the canyon is not directly accessible by roads, it is possible to view part of the canyon from the Grand County road that passes along its southern rim, as part of the Colorado Headwaters Scenic Byway.
The California Zephyr travels through the canyon. Gore Canyon is famous for its wild class V whitewater. "Captain" Samuel Adams considered it unnavigable by boat during his expedition in the 19th century. The construction of the railroad has added boulders and other hazards that have since made the river more difficult. Today, expert kayakers and rafters frequent the canyon, now hold a river festival including races and other river celebrations; the Gore Canyon Whitewater Festival is held every year on the third Saturday of August and is the host of the US National White Water Rafting Championship. Gore Canyon was first rafted in the 1970s, now is available as a commercial river raft trip. Most outfitters agree that Gore Canyon's whitewater is the wildest commercially available whitewater rafting in the state of Colorado, in the nation; those who are brave enough to raft or kayak Gore Canyon will run rapids such as Pyrite, Tunnel Falls, Gore Rapid. This is true wild water, so for those who are not expert river runners, Gore Canyon is considered a dangerous section of the Colorado River.
American Whitewater's Gore Canyon page
An embankment dam is a large artificial dam. It is created by the placement and compaction of a complex semi-plastic mound of various compositions of soil, clay, or rock, it has a semi-pervious waterproof natural covering for a dense, impervious core. This makes such a dam impervious to seepage erosion; such a dam is composed of fragmented independent material particles. The friction and interaction of particles binds the particles together into a stable mass rather than by the use of a cementing substance. Embankment dams come in two types: the earth-filled dam made of compacted earth, the rock-filled dam. A cross-section of an embankment dam shows a shape like hill. Most have a central section or core composed of an impermeable material to stop water from seeping through the dam; the core can be of concrete, or asphalt concrete. This dam type is a good choice for sites with wide valleys, they can be built on softer soils. For a rock-fill dam, rock-fill is blasted using explosives to break the rock.
Additionally, the rock pieces may need to be crushed into smaller grades to get the right range of size for use in an embankment dam. The building of a dam and the filling of the reservoir behind it places a new weight on the floor and sides of a valley; the stress of the water increases linearly with its depth. Water pushes against the upstream face of the dam, a nonrigid structure that under stress behaves semiplastically, causes greater need for adjustment near the base of the dam than at shallower water levels, thus the stress level of the dam must be calculated in advance of building to ensure that its break level threshold is not exceeded. Overtopping or overflow of an embankment dam beyond its spillway capacity will cause its eventual failure; the erosion of the dam's material by overtopping runoff will remove masses of material whose weight holds the dam in place and against the hydraulic forces acting to move the dam. A small sustained overtopping flow can remove thousands of tons of overburden soil from the mass of the dam within hours.
The removal of this mass unbalances the forces that stabilize the dam against its reservoir as the mass of water still impounded behind the dam presses against the lightened mass of the embankment, made lighter by surface erosion. As the mass of the dam erodes, the force exerted by the reservoir begins to move the entire structure; the embankment, having no elastic strength, would begin to break into separate pieces, allowing the impounded reservoir water to flow between them and removing more material as it passes through. In the final stages of failure the remaining pieces of the embankment would offer no resistance to the flow of the water and continue to fracture into smaller and smaller sections of earth or rock until these would disintegrate into a thick mud soup of earth and water. Therefore, safety requirements for the spillway are high, require it to be capable of containing a maximum flood stage, it is common for its specifications to be written such. A number of embankment dam overtopping protection systems have been developed.
These techniques include the concrete overtopping protection systems, timber cribs, sheet-piles and gabions, reinforced earth, minimum energy loss weirs, embankment overflow stepped spillways and the precast concrete block protection systems. Earth structure Gravity dam List of largest dams in the world Embankment dams Table of contents An introduction to embankment dams 100 Years of Embankment Dam Design and Construction in the U. S. Bureau of Reclamation
A dam is a barrier that stops or restricts the flow of water or underground streams. Reservoirs created by dams not only suppress floods but provide water for activities such as irrigation, human consumption, industrial use and navigability. Hydropower is used in conjunction with dams to generate electricity. A dam can be used to collect water or for storage of water which can be evenly distributed between locations. Dams serve the primary purpose of retaining water, while other structures such as floodgates or levees are used to manage or prevent water flow into specific land regions; the earliest known dam is the Jawa Dam in Jordan, dating to 3,000 BC. The word dam can be traced back to Middle English, before that, from Middle Dutch, as seen in the names of many old cities; the first known appearance of dam occurs in 1165. However, there is one village, mentioned in 1120; the word seems to be related to the Greek word taphos, meaning "grave" or "grave hill". So the word should be understood as "dike from dug out earth".
The names of more than 40 places from the Middle Dutch era such as Amsterdam and Rotterdam bear testimony to the use of the word in Middle Dutch at that time. Early dam building took place in the Middle East. Dams were used to control the water level, for Mesopotamia's weather affected the Tigris and Euphrates rivers; the earliest known dam is the Jawa Dam in Jordan, 100 kilometres northeast of the capital Amman. This gravity dam featured an 9-metre-high and 1 m-wide stone wall, supported by a 50 m-wide earth rampart; the structure is dated to 3000 BC. The Ancient Egyptian Sadd-el-Kafara Dam at Wadi Al-Garawi, located about 25 km south of Cairo, was 102 m long at its base and 87 m wide; the structure was built around 2800 or 2600 BC as a diversion dam for flood control, but was destroyed by heavy rain during construction or shortly afterwards. During the Twelfth Dynasty in the 19th century BC, the Pharaohs Senosert III, Amenemhat III and Amenemhat IV dug a canal 16 km long linking the Fayum Depression to the Nile in Middle Egypt.
Two dams called Ha-Uar running east-west were built to retain water during the annual flood and release it to surrounding lands. The lake called "Mer-wer" or Lake Moeris is known today as Birket Qarun. By the mid-late third millennium BC, an intricate water-management system within Dholavira in modern-day India was built; the system included 16 reservoirs and various channels for collecting water and storing it. One of the engineering wonders of the ancient world was the Great Dam of Marib in Yemen. Initiated somewhere between 1750 and 1700 BC, it was made of packed earth – triangular in cross section, 580 m in length and 4 m high – running between two groups of rocks on either side, to which it was linked by substantial stonework. Repairs were carried out during various periods, most important around 750 BC, 250 years the dam height was increased to 7 m. After the end of the Kingdom of Saba, the dam fell under the control of the Ḥimyarites who undertook further improvements, creating a structure 14 m high, with five spillway channels, two masonry-reinforced sluices, a settling pond, a 1,000 m canal to a distribution tank.
These extensive works were not finalized until 325 AD and allowed the irrigation of 25,000 acres. Eflatun Pınar is a Hittite spring temple near Konya, Turkey, it is thought to be from the time of the Hittite empire between the 15th and 13th century BC. The Kallanai is constructed of unhewn stone, over 300 m long, 4.5 m high and 20 m wide, across the main stream of the Kaveri river in Tamil Nadu, South India. The basic structure dates to the 2nd century AD and is considered one of the oldest water-diversion or water-regulator structures in the world, still in use; the purpose of the dam was to divert the waters of the Kaveri across the fertile delta region for irrigation via canals. Du Jiang Yan is the oldest surviving irrigation system in China that included a dam that directed waterflow, it was finished in 251 BC. A large earthen dam, made by Sunshu Ao, the prime minister of Chu, flooded a valley in modern-day northern Anhui province that created an enormous irrigation reservoir, a reservoir, still present today.
Roman dam construction was characterized by "the Romans' ability to plan and organize engineering construction on a grand scale." Roman planners introduced the then-novel concept of large reservoir dams which could secure a permanent water supply for urban settlements over the dry season. Their pioneering use of water-proof hydraulic mortar and Roman concrete allowed for much larger dam structures than built, such as the Lake Homs Dam the largest water barrier to that date, the Harbaqa Dam, both in Roman Syria; the highest Roman dam was the Subiaco Dam near Rome. Roman engineers made routine use of ancient standard designs like embankment dams and masonry gravity dams. Apart from that, they displayed a high degree of inventiveness, introducing most of the other basic dam designs, unknown until then; these include arch-gravity dams, arch dams, buttress dams and multiple arch buttress dams, all of which were known and employed by the 2nd century AD. Roman workforces were the first to build dam bridges, such as the Bridge of Valerian in Iran
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
Denver the City and County of Denver, is the capital and most populous municipality of the U. S. state of Colorado. Denver is located in the South Platte River Valley on the western edge of the High Plains just east of the Front Range of the Rocky Mountains; the Denver downtown district is east of the confluence of Cherry Creek with the South Platte River 12 mi east of the foothills of the Rocky Mountains. Denver is named after James W. Denver, a governor of the Kansas Territory, it is nicknamed the Mile High City because its official elevation is one mile above sea level; the 105th meridian west of Greenwich, the longitudinal reference for the Mountain Time Zone, passes directly through Denver Union Station. Denver is ranked as a Beta world city by World Cities Research Network. With an estimated population of 704,621 in 2017, Denver is the 19th-most populous U. S. city, with a 17.41% increase since the 2010 United States Census, it has been one of the fastest-growing major cities in the United States.
The 10-county Denver-Aurora-Lakewood, CO Metropolitan Statistical Area had an estimated 2017 population of 2,888,227 and is the 19th most populous U. S. metropolitan statistical area. The 12-city Denver-Aurora, CO Combined Statistical Area had an estimated 2017 population of 3,515,374 and is the 15th most populous U. S. metropolitan area. Denver is the most populous city of the 18-county Front Range Urban Corridor, an oblong urban region stretching across two states with an estimated 2017 population of 4,895,589. Denver is the most populous city within a 500-mile radius and the second-most populous city in the Mountain West after Phoenix, Arizona. In 2016, Denver was named the best place to live in the United States by U. S. News & World Report. In the summer of 1858, during the Pike's Peak Gold Rush, a group of gold prospectors from Lawrence, Kansas established Montana City as a mining town on the banks of the South Platte River in what was western Kansas Territory; this was the first historical settlement in what was to become the city of Denver.
The site faded however, by the summer of 1859 it was abandoned in favor of Auraria and St. Charles City. On November 22, 1858, General William Larimer and Captain Jonathan Cox, both land speculators from eastern Kansas Territory, placed cottonwood logs to stake a claim on the bluff overlooking the confluence of the South Platte River and Cherry Creek, across the creek from the existing mining settlement of Auraria, on the site of the existing townsite of St. Charles. Larimer named the townsite Denver City to curry favor with Kansas Territorial Governor James W. Denver. Larimer hoped the town's name would help make it the county seat of Arapaho County but, unbeknownst to him, Governor Denver had resigned from office; the location was accessible to existing trails and was across the South Platte River from the site of seasonal encampments of the Cheyenne and Arapaho. The site of these first towns is now the site of Confluence Park near downtown Denver. Larimer, along with associates in the St. Charles City Land Company, sold parcels in the town to merchants and miners, with the intention of creating a major city that would cater to new immigrants.
Denver City was a frontier town, with an economy based on servicing local miners with gambling, saloons and goods trading. In the early years, land parcels were traded for grubstakes or gambled away by miners in Auraria. In May 1859, Denver City residents donated 53 lots to the Leavenworth & Pike's Peak Express in order to secure the region's first overland wagon route. Offering daily service for "passengers, mail and gold", the Express reached Denver on a trail that trimmed westward travel time from twelve days to six. In 1863, Western Union furthered Denver's dominance of the region by choosing the city for its regional terminus; the Colorado Territory was created on February 28, 1861, Arapahoe County was formed on November 1, 1861, Denver City was incorporated on November 7, 1861. Denver City served as the Arapahoe County Seat from 1861 until consolidation in 1902. In 1867, Denver City became the acting territorial capital, in 1881 was chosen as the permanent state capital in a statewide ballot.
With its newfound importance, Denver City shortened its name to Denver. On August 1, 1876, Colorado was admitted to the Union. Although by the close of the 1860s, Denver residents could look with pride at their success establishing a vibrant supply and service center, the decision to route the nation's first transcontinental railroad through Cheyenne, rather than Denver, threatened the prosperity of the young town. A daunting 100 miles away, citizens mobilized to build a railroad to connect Denver to the transcontinental railroad. Spearheaded by visionary leaders including Territorial Governor John Evans, David Moffat, Walter Cheesman, fundraising began. Within three days, $300,000 had been raised, citizens were optimistic. Fundraising stalled before enough was raised, forcing these visionary leaders to take control of the debt-ridden railroad. Despite challenges, on June 24, 1870, citizens cheered as the Denver Pacific completed the link to the transcontinental railroad, ushering in a new age of prosperity for Denver.
Linked to the rest of the nation by rail, Denver prospered as a service and supply center. The young city grew during these years, attracting millionaires with their mansions, as well as the poverty and crime of a growing city. Denver citizens were proud when the rich chose Denver and were thrilled when Horace Tabor, the Leadville mining millionaire, built an impressive business block at 16th and Larimer as well as the el
Horseshoe Bend (Arizona)
Horseshoe Bend is a horseshoe-shaped incised meander of the Colorado River located near the town of Page, Arizona, in the United States. Horseshoe Bend is located 5 miles downstream from the Glen Canyon Dam and Lake Powell within Glen Canyon National Recreation Area, about 4 miles southwest of Page, it is accessible via hiking a 1.5-mile round trip from U. S. Route 89. Horseshoe Bend can be viewed from the steep cliff above; the overlook is 4,200 feet above sea level, the Colorado River is at 3,200 feet above sea level, making it a 1,000-foot drop. The rock walls of Horseshoe Bend contain hematite, platinum and other minerals. By 2018 references to the location on social media had caused the number of visitors to increase significantly. Official website