1.
San Juan Skyway
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The San Juan Skyway is an All-American Road and a component in the Colorado Scenic and Historic Byway System. It forms a 233. 0-mile loop in the southwest part of the U. S. state of Colorado traversing the heart of the San Juan Mountains and its origin can be traced to the Around the Circle Route promoted by the D&RG. Starting in Durango, Colorado, the largest city on San Juan Skyway, the byway turns north at Cortez, following State Highway 145 through the town of Dolores and the Dolores River into the San Juan National Forest. The byway passes through Rico, county seat of Dolores County prior to 1941, from Rico the byway crosses 10,222 ft Lizard Head Pass and enters the Uncompahgre National Forest. Lizard Head Pass provides views of the 14, 159-foot El Diente Peak, the 14, 246-foot Mount Wilson, the 14, 017-foot Wilson Peak and the passs namesake, the 13, 113-foot Lizard Head Peak. The byway descends near the town of Ophir past the location of the Ophir Loop of the Rio Grande Southern Railroad, a spur road heads off to the mining town turned ski resort of Telluride. The byway follows the San Miguel River to the town of Placerville, the byway turns east at Placerville onto SH62 and follows it over Dallas Divide. There are many excellent views of the San Juan Mountains, especially of the mountains around the 14, from top of the divide the byway descends into the town of Ridgway. The entire route of the byway from Durango to Ridgway roughly follows the route of the Rio Grande Southern Railroad, from Ridgway, the byway turns south onto US550 following the Uncompahgre River into the Victorian mining town of Ouray. The highway is referred to as the Million Dollar Highway from Ouray south back to Durango, for the first 7.0 miles south of Ouray the byway follows through the Uncompahgre Gorge. Just past the tunnel on the route, just south of Ouray. The Alpine Loop National Back Country Byway, a four wheel drive jeep road, before leaving the gorge the byway passes through a snow shed under the Riverside Slide avalanche zone. A monument stands near here honoring those who have lost their lives in the avalanche, at this point the byway enters Ironton Park, a nice flat valley in contrast to the gorge. The road ascends several switchbacks, or S-curves, past the Idarado mining operation to the 11, 018-foot summit of Red Mountain Pass, providing views of Red Mountain, Back into the San Juan National Forest the highway descends through the Chattanooga Valley to Silverton. From Silverton the byway passes over the 10, 910-foot Molas Pass, from Hermosa, the road parallels the Durango and Silverton narrow gauge railroad before returning to Durango. The San Juan Skyway was designated as a National Forest Scenic Byway in September 1988 and it was later named a Colorado Scenic and Historic Byway in 1989 and an All-American Road in September 1996. Colorados Scenic and History Byways - San Juan Skyway
2.
Uncompahgre Peak
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Uncompahgre Peak is the sixth highest summit of the Rocky Mountains of North America and the U. S. state of Colorado. The prominent 14, 321-foot fourteener is the highest summit of the San Juan Mountains and the highest point in the basin of the Colorado River. It is located in the Uncompahgre Wilderness in the northern San Juans, Uncompahgre Peak has a broad summit plateau, rising about 1,500 ft above the broad surrounding alpine basins. The south, east and west sides are not particularly steep, like all peaks in the San Juan Mountains, Uncompahgre is of volcanic origin, but is not a volcano. The rock is of quality for climbing, precluding an ascent of the north face. The most popular route for climbing Uncompahgre Peak is Uncompahgre National Forest Service Trail Number 239, the Nellie Creek Road is a four wheel drive road accessed from the Henson Creek Road, about 4 miles west of Lake City. The trail to the summit is a strenuous hike rising 2,919 ft in elevation in about 3.5 mi. It accesses the summit in an ascent, starting from the east, passing over a south-trending ridge
3.
Summit
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A summit is a point on a surface that is higher in elevation than all points immediately adjacent to it. Mathematically, a summit is a maximum in elevation. The topographic terms acme, apex, peak, and zenith are synonymous, the UIAA definition is that a summit is independent if it has a prominence of 30 metres or more, it is a mountain if it has a prominence of at least 300 metres. This can be summarised as follows, A pyramidal peak is an exaggerated form produced by ice erosion of a mountain top, Summit may also refer to the highest point along a line, trail, or route. In many parts of the western United States, the term refers to the highest point along a road, highway. For example, the highest point along Interstate 80 in California is referred to as Donner Summit while the highest point on Interstate 5 is Siskiyou Mountain Summit, geoid Hill List of highest mountains Maxima and minima Nadir Summit accordance Peak finder
4.
Geographic coordinate system
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A geographic coordinate system is a coordinate system used in geography that enables every location on Earth to be specified by a set of numbers, letters or symbols. The coordinates are chosen such that one of the numbers represents a vertical position. A common choice of coordinates is latitude, longitude and elevation, to specify a location on a two-dimensional map requires a map projection. The invention of a coordinate system is generally credited to Eratosthenes of Cyrene. Ptolemy credited him with the adoption of longitude and latitude. Ptolemys 2nd-century Geography used the prime meridian but measured latitude from the equator instead. Mathematical cartography resumed in Europe following Maximus Planudes recovery of Ptolemys text a little before 1300, in 1884, the United States hosted the International Meridian Conference, attended by representatives from twenty-five nations. Twenty-two of them agreed to adopt the longitude of the Royal Observatory in Greenwich, the Dominican Republic voted against the motion, while France and Brazil abstained. France adopted Greenwich Mean Time in place of local determinations by the Paris Observatory in 1911, the latitude of a point on Earths surface is the angle between the equatorial plane and the straight line that passes through that point and through the center of the Earth. Lines joining points of the same latitude trace circles on the surface of Earth called parallels, as they are parallel to the equator, the north pole is 90° N, the south pole is 90° S. The 0° parallel of latitude is designated the equator, the plane of all geographic coordinate systems. The equator divides the globe into Northern and Southern Hemispheres, the longitude of a point on Earths surface is the angle east or west of a reference meridian to another meridian that passes through that point. All meridians are halves of great ellipses, which converge at the north and south poles, the prime meridian determines the proper Eastern and Western Hemispheres, although maps often divide these hemispheres further west in order to keep the Old World on a single side. The antipodal meridian of Greenwich is both 180°W and 180°E, the combination of these two components specifies the position of any location on the surface of Earth, without consideration of altitude or depth. The grid formed by lines of latitude and longitude is known as a graticule, the origin/zero point of this system is located in the Gulf of Guinea about 625 km south of Tema, Ghana. To completely specify a location of a feature on, in, or above Earth. Earth is not a sphere, but a shape approximating a biaxial ellipsoid. It is nearly spherical, but has an equatorial bulge making the radius at the equator about 0. 3% larger than the radius measured through the poles, the shorter axis approximately coincides with the axis of rotation
5.
Mountain range
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A mountain range is a geographic area containing numerous geologically related mountains. A mountain system or system of ranges, sometimes is used to combine several geological features that are geographically related. Mountain ranges are usually segmented by highlands or mountain passes and valleys, individual mountains within 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, most geologically young mountain ranges on the Earths land surface are associated with either the Pacific Ring of Fire or the Alpide Belt. The Andes is 7,000 kilometres long and is considered the worlds longest mountain system. The Alpide belt includes Indonesia and southeast Asia, through the Himalaya, the belt also includes other European and Asian mountain ranges. The Himalayas contain the highest mountains in the world, including Mount Everest, mountain ranges outside of these two systems include the Arctic Cordillera, the Urals, the Appalachians, the Scandinavian Mountains, the Altai Mountains and the Hijaz Mountains. If the definition of a range is stretched to include underwater mountains. The mountain systems of the earth are characterized by a tree structure, the sub-range relationship is often expressed as a parent-child relationship. For example, the White Mountains of New Hampshire and the Blue Ridge Mountains are sub-ranges of the Appalachian Mountains, equivalently, the Appalachians are the parent of the White Mountains and Blue Ridge Mountains, and the White Mountains and the Blue Ridge Mountains are children of the Appalachians. The position of mountains influences climate, such as rain or snow, when air masses move up and over mountains, the air cools producing orographic precipitation. As the air descends on the side, it warms again and is drier. Often, a shadow will affect the leeward side of a range. Mountain ranges are constantly subjected to forces which work to tear them down. Erosion is at work while the mountains are being uplifted and long after until the mountains are reduced to low hills, rivers are traditionally believed to be the principle erosive factor on mountain ranges, with their ability of bedrock incision and sediment transport. The rugged topography of a range is the product of erosion. The basins adjacent to a mountain range are filled with sediments which are buried and turned into sedimentary rock. The early Cenozoic uplift of the Rocky Mountains of Colorado provides an example and this mass of rock was removed as the range was actively undergoing uplift
6.
Rocky Mountains
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The Rocky Mountains, commonly known as the Rockies, are a major mountain range in western North America. The Rocky Mountains stretch more than 3,000 miles from the northernmost part of British Columbia, in western Canada, to New Mexico, in the Southwestern United States. Within the North American Cordillera, the Rockies are somewhat distinct from the Pacific Coast Ranges, the Rocky Mountains were initially formed from 80 million to 55 million years ago during the Laramide orogeny, in which a number of plates began to slide underneath the North American plate. The angle of subduction was shallow, resulting in a belt of mountains running down western North America. Since then, further tectonic activity and erosion by glaciers have sculpted the Rockies into dramatic peaks, at the end of the last ice age, humans started to inhabit the mountain range. The first mention of their present name by a European was in the journal of Jacques Legardeur de Saint-Pierre in 1752, the Rocky Mountains are commonly defined as stretching from the Liard River in British Columbia south to the Rio Grande in New Mexico. The United States definition of the Rockies includes the Cabinet and Salish Mountains of Idaho and their counterparts north of the Kootenai River, the Columbia Mountains, are considered a separate system in Canada, lying to the west of the huge Rocky Mountain Trench. This runs the length of British Columbia from its beginnings in the middle Flathead River valley in western Montana to the bank of the Liard River. The Rockies vary in width from 70 to 300 miles, also west of the Rocky Mountain Trench, farther north and facing the Muskwa Range across the trench, are the Stikine Ranges and Omineca Mountains of the Interior Mountains system of British Columbia. A small area east of Prince George, British Columbia on the side of the Trench. In Canada geographers define three main groups of ranges, the Continental Ranges, Hart Ranges and Muskwa Ranges, the Muskwa and Hart Ranges together comprise what is known as the Northern Rockies. The western edge of the Rockies includes ranges such as the Wasatch near Salt Lake City, the Great Basin and Columbia River Plateau separate these sub-ranges from distinct ranges further to the west, most prominent among which are the Sierra Nevada, Cascade Range and Coast Mountains. The Rocky Mountain System within the United States is a United States physiographic region, the Rocky Mountains are notable for containing the highest peaks in central North America. The ranges highest peak is Mount Elbert located in Colorado at 14,440 feet above sea level, Mount Robson in British Columbia, at 12,972 feet, is the highest peak in the Canadian Rockies. The Continental Divide of the Americas is located in the Rocky Mountains, triple Divide Peak in Glacier National Park is so named because water that falls 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, see Rivers of the Rocky Mountains for a list of rivers. Human population is not very dense in the Rocky Mountains, with an average of four people per square kilometer, however, the human population grew rapidly in the Rocky Mountain states between 1950 and 1990. The 40-year statewide increases in range from 35% in Montana to about 150% in Utah
7.
Colorado
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Colorado is a state in the United States encompassing most of the Southern Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains. Colorado is part of the Western United States, the Southwestern United States, Colorado is the 8th most extensive and the 21st most populous of the 50 United States. The United States Census Bureau estimates that the population of Colorado was 5,540,545 on July 1,2016, the state was named for the Colorado River, which Spanish travelers named the Río Colorado for the ruddy silt the river carried from the mountains. The Territory of Colorado was organized on February 28,1861, Colorado is nicknamed the Centennial State because it became a state in the same year as the centennial of the United States Declaration of Independence. Colorado is noted for its landscape of mountains, forests, high plains, mesas, canyons, plateaus, rivers. Denver is the capital and the most populous city of Colorado, residents of the state are properly known as Coloradans, although the term Coloradoan has been used archaically and lives on in the title of Fort Collins newspaper, the Coloradoan. Colorado, Wyoming and Utah are the states which have boundaries defined solely by lines of latitude and longitude. The summit of Mount Elbert at 14,440 feet elevation in Lake County is the highest point in Colorado, 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 this point, which holds the distinction of being the highest low elevation point of any state, is higher than the high elevation points of 18 states and the District of Columbia. A little less than one half of the area of Colorado is flat, East of the Rocky Mountains are the Colorado Eastern Plains of the High Plains, the section of the Great Plains within Nebraska at elevations ranging from roughly 3,350 to 7,500 feet. The Colorado plains were mostly prairies, but they have many patches of forests, buttes. Eastern Colorado is presently covered in farmland and rangeland, along with small farming villages. Precipitation is fair, averaging from 15 to 25 inches annually, corn, wheat, hay, soybeans, and oats are all typical crops, and most of the villages and towns in this region boast both a water tower and a grain elevator. Irrigation water is available from the South Platte, the Arkansas River, and a few other streams, however, heavy use of ground water from wells for irrigation has caused underground water reserves to decline. As well as agriculture, eastern Colorado hosts considerable livestock, such as cattle ranches. Roughly 70% of Colorados population resides along the edge of the Rocky Mountains in the Front Range Urban Corridor between Cheyenne, Wyoming, and Pueblo, Colorado. This region is 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, Colorado Springs, Pueblo, Greeley and other townships, on the other side of the Rockies, the significant population centers in Western Colorado are the cities of Grand Junction, Durango, and Montrose
8.
New Mexico
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New Mexico is a state located in the southwestern region of the United States of America. It was admitted to the Union as the 47th state on January 6,1912 and it is usually considered one of the Mountain States. New Mexico is fifth by area, the 36th-most populous, inhabited by Native Americans for thousands of years before European exploration, New Mexico was colonized by the Spanish in 1598 Imperial Spanish viceroyalty of New Spain. Later, it was part of independent Mexico before becoming a U. S. territory and eventually a U. S. state as a result of the Mexican–American War. Among U. S. states, New Mexico has the highest percentage of Hispanics, the major Native American nations in the state are Navajo, Pueblo, and Apache peoples. The demography and culture of the state are shaped by these strong Hispanic and Native American influences and its scarlet and gold colors are taken from the royal standards of Spain, along with the ancient sun symbol of the Zia, a Pueblo-related tribe. New Mexico, or Nuevo México in Spanish, is incorrectly believed to have taken its name from the nation of Mexico. The name simply stuck, even though the area had no connection to Mexico or the Mexica Indian tribes, Mexico, formerly a part of New Spain, adopted its name centuries later in 1821, after winning independence from Spanish rule. New Mexico was a part of the independent Mexican Empire and Federal Republic of Mexico for 27 years,1821 through 1848, New Mexico and Mexico developed as neighboring Spanish-speaking communities under Spanish rule, with relatively independent histories. The states total area is 121,412 square miles, the eastern border of New Mexico lies along 103° W longitude with the state of Oklahoma, and 2.2 miles west of 103° W longitude with Texas. On the southern border, Texas makes up the eastern two-thirds, while the Mexican states of Chihuahua and Sonora make up the western third, the western border with Arizona runs along the 109°03 W longitude. The southwestern corner of the state is known as the Bootheel, the 37° N latitude parallel forms the northern boundary with Colorado. The states New Mexico, Colorado, Arizona, and Utah come together at the Four Corners in the corner of New Mexico. New Mexico, although a state, has very little water. Its surface water area is about 250 square miles, the New Mexican landscape ranges from wide, rose-colored deserts to broken mesas to high, snow-capped peaks. Despite New Mexicos arid image, heavily forested mountain wildernesses cover a significant portion of the state, the Sangre de Cristo Mountains, the southernmost part of the Rocky Mountains, run roughly north-south along the east side of the Rio Grande in the rugged, pastoral north. The most important of New Mexicos rivers are the Rio Grande, Pecos, Canadian, San Juan, the Rio Grande is tied for the fourth-longest river in the United States. Tourists visiting these sites bring significant money to the state, other areas of geographical and scenic interest include Kasha-Katuwe Tent Rocks National Monument and the Gila Wilderness in the southwest of the state
9.
Mineral
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A mineral is a naturally occurring chemical compound, usually of crystalline form and abiogenic in origin. A mineral has one specific chemical composition, whereas a rock can be an aggregate of different minerals or mineraloids, the study of minerals is called mineralogy. There are over 5,300 known mineral species, over 5,070 of these have been approved by the International Mineralogical Association, the silicate minerals compose over 90% of the Earths crust. The diversity and abundance of species is controlled by the Earths chemistry. Silicon and oxygen constitute approximately 75% of the Earths crust, which translates directly into the predominance of silicate minerals, minerals are distinguished by various chemical and physical properties. Differences in chemical composition and crystal structure distinguish the various species, changes in the temperature, pressure, or bulk composition of a rock mass cause changes in its minerals. Minerals can be described by their various properties, which are related to their chemical structure. Common distinguishing characteristics include crystal structure and habit, hardness, lustre, diaphaneity, colour, streak, tenacity, cleavage, fracture, parting, more specific tests for describing minerals include magnetism, taste or smell, radioactivity and reaction to acid. Minerals are classified by key chemical constituents, the two dominant systems are the Dana classification and the Strunz classification, the silicate class of minerals is subdivided into six subclasses by the degree of polymerization in the chemical structure. All silicate minerals have a unit of a 4− silica tetrahedron—that is, a silicon cation coordinated by four oxygen anions. These tetrahedra can be polymerized to give the subclasses, orthosilicates, disilicates, cyclosilicates, inosilicates, phyllosilicates, other important mineral groups include the native elements, sulfides, oxides, halides, carbonates, sulfates, and phosphates. The first criterion means that a mineral has to form by a natural process, stability at room temperature, in the simplest sense, is synonymous to the mineral being solid. More specifically, a compound has to be stable or metastable at 25 °C, modern advances have included extensive study of liquid crystals, which also extensively involve mineralogy. Minerals are chemical compounds, and as such they can be described by fixed or a variable formula, many mineral groups and species are composed of a solid solution, pure substances are not usually found because of contamination or chemical substitution. Finally, the requirement of an ordered atomic arrangement is usually synonymous with crystallinity, however, crystals are also periodic, an ordered atomic arrangement gives rise to a variety of macroscopic physical properties, such as crystal form, hardness, and cleavage. There have been recent proposals to amend the definition to consider biogenic or amorphous substances as minerals. The formal definition of an approved by the IMA in 1995, A mineral is an element or chemical compound that is normally crystalline. However, if geological processes were involved in the genesis of the compound, Mineral classification schemes and their definitions are evolving to match recent advances in mineral science
10.
Gold
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Gold is a chemical element with symbol Au and atomic number 79. In its purest form, it is a bright, slightly yellow, dense, soft, malleable. Chemically, gold is a metal and a group 11 element. It is one of the least reactive chemical elements and is solid under standard conditions, Gold often occurs in free elemental form, as nuggets or grains, in rocks, in veins, and in alluvial deposits. It occurs in a solid solution series with the element silver and also naturally alloyed with copper. Less commonly, it occurs in minerals as gold compounds, often with tellurium, golds atomic number of 79 makes it one of the higher numbered, naturally occurring elements. It is thought to have produced in supernova nucleosynthesis, from the collision of neutron stars. Because the Earth was molten when it was formed, almost all of the present in the early Earth probably sank into the planetary core. Gold is resistant to most acids, though it does dissolve in aqua regia, a mixture of acid and hydrochloric acid. Gold also dissolves in solutions of cyanide, which are used in mining and electroplating. Gold dissolves in mercury, forming amalgam alloys, but this is not a chemical reaction, as a precious metal, gold has been used for coinage, jewelry, and other arts throughout recorded history. A total of 186,700 tonnes of gold is in existence above ground, the world consumption of new gold produced is about 50% in jewelry, 40% in investments, and 10% in industry. Gold is also used in infrared shielding, colored-glass production, gold leafing, certain gold salts are still used as anti-inflammatories in medicine. As of 2014, the worlds largest gold producer by far was China with 450 tonnes, Gold is cognate with similar words in many Germanic languages, deriving via Proto-Germanic *gulþą from Proto-Indo-European *ǵʰelh₃-. The symbol Au is from the Latin, aurum, the Latin word for gold, the Proto-Indo-European ancestor of aurum was *h₂é-h₂us-o-, meaning glow. This word is derived from the root as *h₂éu̯sōs, the ancestor of the Latin word Aurora. This etymological relationship is presumably behind the frequent claim in scientific publications that aurum meant shining dawn, Gold is the most malleable of all metals, a single gram can be beaten into a sheet of 1 square meter, and an avoirdupois ounce into 300 square feet. Gold leaf can be thin enough to become semi-transparent
11.
Silver
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Silver is a metallic element with symbol Ag and atomic number 47. The symbol Ag stems from Latin argentum, derived from the Greek ὰργὀς, a soft, white, lustrous transition metal, it exhibits the highest electrical conductivity, thermal conductivity, and reflectivity of any metal. The metal is found in the Earths crust in the pure, free form, as an alloy with gold and other metals. Most silver is produced as a byproduct of copper, gold, lead, Silver is more abundant than gold, but it is much less abundant as a native metal. Its purity is measured on a per mille basis, a 94%-pure alloy is described as 0.940 fine. As one of the seven metals of antiquity, silver has had a role in most human cultures. Silver has long valued as a precious metal. Silver metal is used in many premodern monetary systems in bullion coins, Silver is used in numerous applications other than currency, such as solar panels, water filtration, jewelry, ornaments, high-value tableware and utensils, and as an investment medium. Silver is used industrially in electrical contacts and conductors, in specialized mirrors, window coatings, Silver compounds are used in photographic film and X-rays. Dilute silver nitrate solutions and other compounds are used as disinfectants and microbiocides, added to bandages and wound-dressings, catheters. Silver is similar in its physical and chemical properties to its two neighbours in group 11 of the periodic table, copper and gold. This distinctive electron configuration, with an electron in the highest occupied s subshell over a filled d subshell. Silver is a soft, ductile and malleable transition metal. Silver crystallizes in a cubic lattice with bulk coordination number 12. Unlike metals with incomplete d-shells, metallic bonds in silver are lacking a covalent character and are relatively weak and this observation explains the low hardness and high ductility of single crystals of silver. Silver has a brilliant white metallic luster that can take a polish. Protected silver has greater optical reflectivity than aluminium at all wavelengths longer than ~450 nm, at wavelengths shorter than 450 nm, silvers reflectivity is inferior to that of aluminium and drops to zero near 310 nm. The electrical conductivity of silver is the greatest of all metals, greater even than copper, during World War II in the US,13540 tons of silver were used in electromagnets for enriching uranium, mainly because of the wartime shortage of copper
12.
Mining camp
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A mining community, also known as a mining town or a mining camp, is a community that houses miners. Mining communities are created around a mine or a quarry. Throughout the continental United States and Alaska, valuable minerals were discovered, the miners would usually settle a site and make home of tents and shacks, that miners built by hand. Eventually mining buildings such as smelters or stamp mills would be constructed followed by cabins, stores, a community would naturally be born with the settling of women and children and existed as long as precious metal could be dug from the area. Sometimes the geographical location of a community or the various American railroads would ensure a communitys existence after all the valuable minerals were gone. Many American mining communities became ghost towns though others have become prominent cities, a settlement usually can only be considered a mining community if a mine exists directly at the settlement or within the immediate area and if the population relies on the mine economically. Smelter towns, built for smeltering ore extracted from mines, are considered a type of mining community, book features pg.147 about what is necessary for a settlement to have in order to be considered a mining town
13.
Creede, Colorado
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The historic City of Creede is the Statutory Town that is the county seat and the only incorporated municipality in Mineral County, Colorado, United States. The town population was 290 at the 2010 United States Census, travelers to this area appeared in the early 19th century. Tom Boggs, a brother-in-law of Kit Carson, farmed at Wagon Wheel Gap in the summer of 1840, the first silver discovery was made at the Alpha mine in 1869, but the silver could not be extracted at a profit from the complex ores. Ranchers and homesteaders moved in when stagecoach stations were built in the 1870s, Creede was the last silver boom town in Colorado in the 19th century. The town leapt from a population of 600 in 1889 to more than 10,000 people in December 1891, the Creede mines operated continuously from 1890 until 1985, and were served by the Denver & Rio Grande Railroad. The original townsite of Creede was located on East Willow Creek just above its junction with West Willow Creek, below Creede were Stringtown, Jimtown, and Amethyst. The Willow Creek site was soon renamed Creede after Nicholas C, Creede who discovered the Holy Moses Mine. Soon the entire area from East Willow to Amethyst was called Creede. At the same time that Creede was booming, the city of Denver, Colorado was experiencing a major legal reform movement against gambling clubs. Numerous owners of major gambling houses in Denver quickly relocated to Creedes business district, one of these relocators was the infamous confidence man Jefferson Randolph Soapy Smith. Soapy became the king of Creedes criminal underworld, and opened the Orleans Club. Other famous people in Creede were Robert Ford, Bat Masterson, on June 5,1892 a major fire destroyed most of the business district. Three days later, on June 8, Ed OKelley walked into Robert Fords makeshift tent-saloon, the town of Creede was incorporated on June 13,1892, but the anti-gambling reform movement in Denver had ceased, and the Denver businessmen moved back to their old stomping grounds. Creede’s boom lasted until 1893, when the Silver Panic hit all of the mining towns in Colorado. The price of silver plummeted and most of the mines were closed. Creede never became a ghost town, although the boom was over, after 1900, Creede stayed alive by relying increasingly on lead and zinc in the ores. The river has played a role in the development of farming and ranching in the Valley. The Rio Grande and its trout streams provide excellent opportunities for fly fishermen
14.
Lake City, Colorado
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The Town of Lake City is the Statutory Town that is the county seat and the only incorporated municipality in Hinsdale County, Colorado, United States. Lake City is named after nearby Lake San Cristobal, with the completion of the first road into the mountains in this region, Lake City served as a supply center for the many miners and prospectors flooding into the area. As a supply center, the town boomed to as many as 3,000 to 5,000 settlers, but as the first-discovered deposits were found to be only moderately productive and no new extensive or rich deposits of minerals were found, by 1879 the boom had subsided. With the arrival of the Denver & Rio Grande Railroad in 1889, by 1905, the mining era was over and Lake City entered a decades-long period of economic decline. Population figures hovered at 1,000 then dropped to 400 after 1910, although mining continued throughout the twentieth century, it consisted primarily of exploration and speculation rather than productive operation. Beginning in 1915, visitors began coming to Lake City for the summer season. The Hinsdale County Historical Society formed in 1973 and began accumulating documents, in 1978, the Lake City Historic District was listed in the National Register of Historic Places. Residents have restored many of the boom town mining era buildings, the town population was 408 at the 2010 United States Census. Lake Citys educational needs are served by the Lake City Community School, prior to written history, the Ute people lived in this area of the San Juan Mountain Range where they hunted and fished in the high mountain valleys during the summers. Even though the land was owned by the Utes as part of a treaty that set the area aside as a tribal reservation, by the 1860s prospectors had begun to enter the region in search of minerals. When rich silver deposits were found in the Lake City area, word spread, consequently, the native population was again pushed from their lands when in 1873, a new treaty was negotiated under which the Utes gave up their rights to the San Juan Mountains. In 1873, the town of Lake City was incorporated as a center for the prospectors and miners who were flooding the area. Lake City was platted in fall 1874 during construction of the Saguache & San Juan Wagon Toll Road, Town developers chose this location for the town site because of its flat terrain and abundant water. The broad valley provided a setting which the optimistic town developers used to their advantage. They laid out a 260-acre town site that occupied the valley floor -72 blocks of 32 uniform city lots,25 x 125 in size. To promote the town, Otto Mears subsidized The Silver World newspaper. It was the first newspaper published on the Western Slope and it was not unusual for mining towns to grow into boom towns within a matter of only a few months, and Lake City was no exception. Promoted as the Metropolis of San Juan, the town flourished as a point for goods and supplies forwarded to mines
15.
Silverton, Colorado
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The town of Silverton is a Statutory Town that is the county seat of, and the only incorporated municipality in San Juan County, Colorado, United States. Silverton is a silver mining camp, most or all of which is now included in a federally designated National Historic Landmark District. The town population reached its nadir at 531 at U. S. Census 2000, Silverton is linked to Durango by the Durango and Silverton Narrow Gauge Railroad, a National Historic Landmark. Silverton no longer has active mining, but subsists by tourism, maintenance of US550, mine pollution remediation, in 2002 an extreme ski mountain, Silverton Mountain, opened near the town. According to the United States Census Bureau, the town has an area of 0.8 square miles. Silverton is one of the highest towns in the United States and this is also where the book The Christopher Killer takes place. Silverton has a subarctic climate with very cold, snowy winters. Charles Bakers group of prospectors found traces of gold in the San Juan Mountains in 1860 at Eureka. Forced out by the Ute Tribe in 1861, who had awarded the area in a US treaty. The prospectors returned in 1871, when gold was found in the Little Giant vein at Arrastre Gulch. The miners were allowed to stay after the Brunot Treaty of 13 Sept.1873, in exchange for giving up 4 million acres, the Southern Ute Indian Reservation received $25,000 per year. In August 1873, George Howard and R. J. McNutt discovered the Sunnyside silver vein along Hurricane Peak, Gold was then discovered in 1882. The Sunnyside Mine was shut down after the 1929 stock market crash, but was acquired by Standard Metals Corp. in 1959, half of Colorados gold production in the 1970s came from the Sunnyside. The mine reopened after two years, but was acquired by Echo Bay Mines in 1986, which operated the mine for another five years, the nearby Gold King mine breached and spilled into Cement Creek, causing the 2015 Gold King Mine waste water spill. As of the census of 2000, there were 531 people,255 households, the population density was 656.0 people per square mile. There were 430 housing units at a density of 531.2 per square mile. The racial makeup of the town was 97. 36% White,0. 75% Native American,0. 38% Pacific Islander,0. 75% from other races, hispanic or Latino of any race were 7. 72% of the population. 36. 9% of all households were made up of individuals and 4. 7% had someone living alone who was 65 years of age or older, the average household size was 2.06 and the average family size was 2.63
16.
Ouray, Colorado
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Ouray /ˈjʊəreɪ/ is a Home Rule Municipality that is the county seat and the most populous city of Ouray County, Colorado, United States. The city population was 813 at the U. S. Census 2000 and 1,000 as of the U. S. Census 2010, the Ouray Post Office has the ZIP code 81427. Originally established by miners chasing silver and gold in the surrounding mountains, prospectors arrived in the area in 1875. In 1877, William Weston and George Barber found the Gertrude and Una gold veins in Imogene Basin, Thomas Walsh acquired the two veins and all the open ground nearby. In 1897 opened the Camp Bird Mine, adding a twenty-stamp mill in 1898, the mine produced almost 200,000 ounces of gold by 1902, when Walsh sold out to Camp Bird, Ltd. By 1916, Camp Bird, Ltd. had produced one million ounces of gold. At the height of the mining, Ouray had more than 30 active mines, the town—after changing its name and that of the county it was in several times—was incorporated on October 2,1876, named after Chief Ouray of the Utes, a Native American tribe. By 1877 Ouray had grown to over 1,000 in population and was named county seat of the newly formed Ouray County on March 8,1877, the Denver & Rio Grande Railway arrived in Ouray on December 21,1887. It would stay until the automobile and trucks caused a decline in traffic, the last regularly scheduled passenger train was September 14,1930. The line between Ouray and Ridgway was abandoned on March 21,1953, C. W. McCall, was elected mayor, ultimately serving for six years. The entirety of Main Street is registered as a National Historic District with most of the buildings dating back to the nineteenth century. Ouray is located at 38°1′24″N 107°40′20″W, in the San Juan Mountains of southwestern Colorado and it is about 40 miles south of Montrose. It is only 10 miles northeast of Telluride, but due to the severity of the landscape, Ouray is connected to Silverton and then Durango to the south by Red Mountain Pass which crests at just over 11,000 feet. The drive along the Uncompahgre River and over the pass is nicknamed the Million Dollar Highway, Yankee Boy Basin, located a few miles from town, boasts a beautiful spectacle called Twin Falls. According to the United States Census Bureau, the city has an area of 0.8 square miles. Summers are warm in the day and mild to cool at night with brief thunderstorms often occurring in the afternoons in July and August sometimes resulting in intense, though short lived, autumn is cool and mostly clear with occasional rain. Winters are long and cold—though seldom extremely so—with considerable snowfall, spring is generally cool with early spring often bringing the largest snowfalls, late spring into early summer is mild to warm and is usually the driest time of year. The Köppen climate classification for Ouray is Dfb, the entire present-day economy of Ouray is based on tourism
17.
Telluride, Colorado
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The town of Telluride is the county seat and most populous town of San Miguel County in the southwestern portion of the U. S. state of Colorado. The town is a silver mining camp on the San Miguel River in the western San Juan Mountains. The first gold mining claim was made in the mountains above Telluride in 1875 and these telluride minerals were never located near Telluride, causing the town to be named for a mineral which was never mined there. However, the mines for some years provided zinc, lead, copper, silver. Telluride sits in a box canyon, steep forested mountains and cliffs surround it, with Bridal Veil Falls at the head of the canyon. Numerous weathered ruins of old mining operations dot the hillsides, a free gondola connects the town with its companion town, Mountain Village, Colorado, at the base of the ski area. Telluride and the area have featured prominently in pop culture. It is the subject of popular songs. It is especially known for its ski resort and slopes during the winter as well as an extensive festival schedule during the summer. The Telluride Historic District, which includes a significant portion of the town, is listed on the National Register of Historic Places and is one of Colorados 20 National Historic Landmarks. The town population was 2,325 in the 2010 United States Census, Gold was first discovered in Colorado near present-day Denver, setting off the Pikes Peak gold rush of 1858. The Smuggler gold vein above Telluride, and placer gold in the San Miguel River, were discovered in 1875, John Fallon made the first claim in Marshal Basin above Telluride in 1875 and early settlement of Telluride followed. The town itself was founded in 1878, Telluride was originally named Columbia, but due to confusion with Columbia, California, the name was changed by the post office in 1887. The town was named after valuable ore compounds of the element tellurium, a metalloid element which forms natural tellurides. Although gold telluride minerals were never found in the mountains near Telluride, the areas mines were rich in zinc, lead, copper, silver. Telluride began slowly because of its isolated location, in 1881, a toll road was opened by Otto Mears which allowed wagons to go where only pack mules could go before. This increased the number of people in Telluride, but it was expensive to get gold-rich ore out of the valley. In June 1889, Butch Cassidy, before becoming associated with his gang and this was his first major recorded crime
18.
Red Mountain Pass (San Juan Mountains)
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Red Mountain Pass elevation 11,018 ft is a mountain pass in the San Juan Mountains of western Colorado in the United States. The pass straddles a divide that separates Ouray and San Juan counties, the pass is named for the nearby Red Mountain on the northeast side of the pass. The name is derived from the iron oxide laden rock that forms their slopes, the pass separates the Uncompahgre and Las Animas River watersheds, and also serves as a dividing point between the Uncompahgre and San Juan National Forests. The pass is traversed by the Million Dollar Highway, U. S. Highway 550 between Ouray and Silverton, which is part of the San Juan Skyway Scenic Byway. The pass is known for being treacherous in the due to the steep 8% grade and switchbacks on the north side facing Ouray. Avalanches are frequent, and can block the highway for some time, the lower part of the pass towards Ouray is blasted into near-vertical cliffs of quartzite hundreds of feet above Red Mountain Creek and the Uncompahgre River. This section of road is winding, narrow and has no shoulder, the Red Mountain Mining District lies from the divide northward to Ironton Park, halfway down towards Ouray. It was the site of a silver boom from 1882-1893, including the Yankee Girl, National Belle and Guston mines. Head frames of the old workings are visible from the highway. The Idarado Mine continued until the 1970s, and reclamation of tailings is ongoing
19.
Camp Bird Mine
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The Camp Bird Mine is a famous and highly productive old gold mine located between Ouray and Telluride, Colorado. The mine is within the Sneffels-Red Mountain-Telluride mining district in the San Juan Mountains and it was discovered by Thomas F. Walsh in 1896, and is owned by the Federal Resources Corp. The mine produced about 1.5 million troy ounces of gold, at 2009 prices, Camp Birds production would be worth over US$1.5 billion. Walsh sold the property for US$5.2 million in 1902, walshs daughter, Evalyn Walsh McLean, later purchased the Hope Diamond. His daughter Evalyn Walsh McLean devotes several chapters to the mine in her autobiography Father Struck It Rich, Camp Bird is named after the Camp Birds, probably Rocky Mountain jays, that ate many a miners lunch. Telluride native David Lavender related his experiences working at the Camp Bird Mine in the 1930s in his classic memoir One Mans West, C. W. McCall sang Way out in Colorado, in the Camp Bird Mine, down deep in the darkness, on level nine. The song moved the mines founding to 1892 to make the rhyme work, the Camp Bird Mine filed for a permit to resume mining in late 2007, but remains inactive as of August 2008. Yankee Boy Basin Camp Bird ghost town, includes photo gallery History of the mine
20.
Summitville mine
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The Summitville mine was a gold mining site in Rio Grande County, Colorado 25 miles south of Del Norte. It is remembered for the damage caused in the 1980s by the leakage of mining by-products into local waterways. Charles Bakers group of prospectors found traces of gold in the San Juan Mountains in 1860 at Eureka. The group was forced out in 1861 by the Ute Tribe, gold was discovered in Wightman Fork, on South Mountain, which is the same location of present-day Summitville. More prospectors returned in 1871, when gold was found in the Little Giant vein at Arrastre Gulch, near Silverton. The miners were allowed to stay after the Brunot Treaty of 13 Sept.1873, in exchange for giving up 4 million acres, the Southern Ute Indian Reservation received $25,000 per year. Gold veins were found at 11,500 feet on South Mountain in 1873, by 1885 there were more than 250 individual claims in operation. The site was mined out, with the weather of the 3,500 m high site adding to difficulties. The site was re-opened on a number of occasions for gold or other metals but with little success, the total amount of gold extracted from the site from 1873 until 1959 was around 257,600 troy ounces. In 1984 an area of 1,230 acres was acquired by the Canadian-based Galactic Resources Ltd. subsidiary Summitville Consolidated Mining Company and they began a new large-scale open pit operation covering 550 acres. New techniques were used to extract gold from otherwise uneconomic ore, the mining involved the treatment of pyritic ore with a sodium cyanide solution to leach the gold out of the ore—heap leaching. The solution was then removed from the ore and the metals extracted using activated carbon. SCMCI leached around 10 million tons of ore on a 73-acre heap leach pad, the mining operations were finished in October 1991 with the leaching continuing until March 1992, when Galactic Resources filed for bankruptcy. A total of 294,365 troy ounces of gold and 319,814 troy ounces of silver were recovered, SCMCI then closed the site and converted on-site equipment for the detoxification process, with around 160 million U. S. gallons of stored water needing treatment. Possibly 85,000 US gallons of contaminated water had leaked into nearby creeks, in December 1992 Galactic Resources Ltd. declared itself bankrupt and declared that the site clean-up operations would halt immediately. The site clean-up was undertaken by the United States Environmental Protection Agency, the main problem was the contaminated water held in an inadequate pond system. Another source of contamination was water leaking from underground workings. The EPA estimated that 3,000 US gallons were leaking from the site every minute, however, despite the water having a pH of around 3, a USGS study stated that the run-off was no serious threat
21.
Cyanide
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A cyanide is any chemical compound that contains monovalent combining group CN. This group, known as the group, consists of a carbon atom triple-bonded to a nitrogen atom. The cyanide ion is isoelectronic with carbon monoxide and with molecular nitrogen, organic cyanides are usually called nitriles, in these, the CN group is linked by a covalent bond to a carbon-containing group, such as methyl in methyl cyanide. Because they do not release cyanide ions, nitriles are generally toxic, or in the case of insoluble polymers such as acrylic fiber. Hydrocyanic acid, also known as hydrogen cyanide, or HCN, is a volatile liquid used to prepare acrylonitrile, which is used in the production of acrylic fibers, synthetic rubber. Cyanides are employed in a number of processes, including fumigation, case hardening of iron and steel, electroplating. In nature, substances yielding cyanide are present in seeds, such as the pit of the cherry. In IUPAC nomenclature, organic compounds that have a functional group are called nitriles. An example of a nitrile is CH3CN, acetonitrile, also known as methyl cyanide, nitriles usually do not release cyanide ions. A functional group with a hydroxyl and cyanide bonded to the carbon is called cyanohydrin. Unlike nitriles, cyanohydridins do release hydrogen cyanide, in inorganic chemistry, salts containing the C≡N− ion are referred to as cyanides. The word is derived from the Greek kyanos, meaning dark blue, cyanides are produced by certain bacteria, fungi, and algae and are found in a number of plants. Cyanides are found in substantial amounts in certain seeds and fruit stones, e. g. those of apricots, apples, in plants, cyanides are usually bound to sugar molecules in the form of cyanogenic glycosides and defend the plant against herbivores. Cassava roots, an important potato-like food grown in tropical countries, the Madagascar bamboo Cathariostachys madagascariensis produces cyanide as a deterrent to grazing. In response, the bamboo lemur, which eats the bamboo, has developed a high tolerance to cyanide. The cyanide radical CN· has been identified in interstellar space, the cyanide radical is used to measure the temperature of interstellar gas clouds. Hydrogen cyanide is produced by the combustion or pyrolysis of certain materials under oxygen-deficient conditions, for example, it can be detected in the exhaust of internal combustion engines and tobacco smoke. Certain plastics, especially derived from acrylonitrile, release hydrogen cyanide when heated or burnt
22.
Tailing pond
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Tailings are distinct from overburden, which is the waste rock or other material that overlies an ore or mineral body and is displaced during mining without being processed. The amount of tailings can be large, ranging from 90–98% for some copper ores to 20–50% of the other minerals. In the latter, the extraction of minerals from ore requires comminution, because of this comminution, tailings consist of a slurry of fine particles, ranging from the size of a grain of sand to a few micrometres. Mine tailings are usually produced from the mill in slurry form, the effluent from the tailings from the mining of sulfidic minerals has been described as the largest environmental liability of the mining industry. These tailings contain large amounts of pyrite and Iron sulfide, which are rejected from the ores of copper and nickel. Although harmless underground, these minerals are reactive toward air in the presence of microorganisms, when applied to coal mining tailings ponds and oil sands tailings ponds, the term tailings refers to fine waste suspended in water. Bauxite tailings is a waste product generated in the production of aluminium. Making provision for the approximately 77 million tons that is produced annually is one of the most significant problems for the mining industry. Early mining operations often did not take steps to make tailings areas environmentally safe after closure. Tailings dams are often the most significant environmental liability for a mining project, the rejected minerals and rocks liberated through mining and processing are not part of the aerobic ecological systems and are unstable. They have the potential to damage the environment by releasing toxic metals, by acid drainage, the greatest danger of tailings ponds is dam failure, with the most publicized failure in the U. S. On average, worldwide, there is one big accident involving a tailings dam each year, other disasters caused by tailings dam failures are, the 2000 Baia Mare cyanide spill and the Ajka alumina plant accident. Historically, tailings were disposed of in the most convenient manner, because of concerns about these sediments in the water and other issues, tailings ponds came into use. Bounded by impoundments, these dams typically use local materials including the tailings themselves, traditionally, the only option for tailings storage was to deal with a tailings slurry. This slurry is a stream of the tailings solids within water that was sent to the tailings storage area. The modern tailings designer has a range of products to choose from depending upon how much water is removed from the slurry prior to discharge. The removal of not only can create a better storage system in some cases. In a 1994 description of tailings impoundments, however, the U. S. EPA stated that dewatering methods may be prohibitively expensive except in special circumstances, subaqueous storage of tailings has also been used
23.
Caldera
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A caldera is a large cauldron-like depression that forms following the evacuation of a magma chamber/reservoir. When large volumes of magma are erupted over a time period. The ground surface then collapses downward into the emptied magma chamber. Although sometimes described as a crater, the feature is actually a type of sinkhole, as it is formed through subsidence, only seven known caldera-forming collapses have occurred since the start of the 20th century, most recently at Bárðarbunga volcano in Iceland. The word comes from Spanish caldera, and this from Latin caldaria, in some texts the English term cauldron is also used. If enough magma is ejected, the chamber is unable to support the weight of the volcanic edifice above it. A roughly circular fracture, the fault, develops around the edge of the chamber. Ring fractures serve as feeders for fault intrusions which are known as ring dykes. Secondary volcanic vents may form above the ring fracture, as the magma chamber empties, the center of the volcano within the ring fracture begins to collapse. The collapse may occur as the result of a cataclysmic eruption. The total area that collapses may be hundreds or thousands of square kilometers, some calderas are known to host rich ore deposits. One of the worlds best-preserved mineralized calderas is the Sturgeon Lake Caldera in northwestern Ontario, Canada, if the magma is rich in silica, the caldera is often filled in with ignimbrite, tuff, rhyolite, and other igneous rocks. Silica-rich magma has a high viscosity, and therefore does not flow easily like basalt, as a result, gases tend to become trapped at high pressure within the magma. Further lava flows may be erupted, if volcanic activity continues, the center of the caldera may be uplifted in the form of a resurgent dome such as is seen at Cerro Galán, Lake Toba, Yellowstone, etc. by subsequent intrusion of magma. A silicic or rhyolitic caldera may erupt hundreds or even thousands of kilometers of material in a single event. Even small caldera-forming eruptions, such as Krakatoa in 1883 or Mount Pinatubo in 1991, may result in significant local destruction, large calderas may have even greater effects. When Yellowstone Caldera last erupted some 650,000 years ago, it released about 1,000 km3 of material, by comparison, when Mount St. Helens erupted in 1980, it released ~1.2 km3 of ejecta. The ecological effects of the eruption of a large caldera can be seen in the record of the Lake Toba eruption in Indonesia, more recently several geneticists, including Lynn Jorde and Henry Harpending have proposed that the human species was reduced to approximately five to ten thousand people
24.
Volcano
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A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. Earths volcanoes occur because its crust is broken into 17 major, therefore, on Earth, volcanoes are generally found where tectonic plates are diverging or converging. This type of volcanism falls under the umbrella of plate hypothesis volcanism, Volcanism away from plate boundaries has also been explained as mantle plumes. These so-called hotspots, for example Hawaii, are postulated to arise from upwelling diapirs with magma from the boundary,3,000 km deep in the Earth. Volcanoes are usually not created where two plates slide past one another. Erupting volcanoes can pose hazards, not only in the immediate vicinity of the eruption. Historically, so-called volcanic winters have caused catastrophic famines, the word volcano is derived from the name of Vulcano, a volcanic island in the Aeolian Islands of Italy whose name in turn comes from Vulcan, the god of fire in Roman mythology. The study of volcanoes is called volcanology, sometimes spelled vulcanology, at the mid-oceanic ridges, two tectonic plates diverge from one another as new oceanic crust is formed by the cooling and solidifying of hot molten rock. Most divergent plate boundaries are at the bottom of the oceans, therefore, most volcanic activity is submarine, black smokers are evidence of this kind of volcanic activity. Where the mid-oceanic ridge is above sea-level, volcanic islands are formed, for example, subduction zones are places where two plates, usually an oceanic plate and a continental plate, collide. In this case, the plate subducts, or submerges under the continental plate forming a deep ocean trench just offshore. In a process called flux melting, water released from the subducting plate lowers the temperature of the overlying mantle wedge. This magma tends to be very viscous due to its high content, so it often does not reach the surface. When it does reach the surface, a volcano is formed, typical examples of this kind of volcano are Mount Etna and the volcanoes in the Pacific Ring of Fire. Because tectonic plates move across them, each volcano becomes dormant and is eventually re-formed as the plate advances over the postulated plume and this theory is currently under criticism, however. The most common perception of a volcano is of a mountain, spewing lava and poisonous gases from a crater at its summit, however. The features of volcanoes are more complicated and their structure. Some volcanoes have rugged peaks formed by lava domes rather than a summit crater while others have features such as massive plateaus
25.
La Garita Caldera
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La Garita Caldera is a large volcanic caldera located in the San Juan volcanic field in the San Juan Mountains near the town of Creede in southwestern Colorado, United States. It is west of La Garita, Colorado, the eruption that created the La Garita Caldera is among the largest known volcanic eruptions in Earths history. 01±0.04 million years ago, during the Oligocene Epoch. The area devastated by the La Garita eruption is thought to have covered a significant portion of what is now Colorado, the deposit, known as the Fish Canyon Tuff, covered at least 30,000 km2. Its average thickness is 100 m, the eruption might have formed a large-area ash-fall, but none has yet been identified. The scale of La Garita volcanism was the second greatest of the Cenozoic Era, the resulting Fish Canyon Tuff has a volume of approximately 1,200 cubic miles, rating it an 8 on the Volcanic Explosivity Index. This is enough material to fill Lake Michigan, by comparison, the May 18,1980, eruption of Mt. St. Helens was 0.25 cubic miles in volume. By contrast, the most powerful explosive device ever detonated. It is the most energetic event to have taken place on Earth since the Chicxulub impact which, the Fish Canyon Tuff, made of dacite, is uniform in its petrological composition and forms a single cooling unit despite the huge volume. Dacite is a volcanic rock common in explosive eruptions, lava domes. There are also large intracaldera lavas composed of andesite, a volcanic rock compositionally intermediate between basalt and dacite in the La Garita Caldera, the caldera itself, like the eruption of Fish Canyon Tuff, is quite large in scale. It is 35 by 75 kilometers and oblong in shape, most supervolcano calderas of explosive origin are slightly ovoid or oblong in shape. Because of the vast scale and erosion, it took scientists over 30 years to determine the size of the caldera. La Garita is considered an extinct volcano, La Garita is also the source of at least 7 major eruptions of welded tuff deposits over a span of 1.5 million years since the Fish Canyon Tuff eruption. The caldera is known to have extensive outcrops of a very unusual lava-like rock unit, called the Pagosa Peak Dacite. The Pagosa Peak Dacite, which has characteristics of lava and welded tuff, was erupted probably shortly before the Fish Canyon Tuff. The Pagosa Peak Dacite has been interpreted as having erupted as thick spatter during low-energy lava fountaining and has a volume of about 200–300 cubic kilometers. These rocks had been identified as lava because the unit has an aspect ratio. However, the Pagosa Peak Dacite formed by low-column pyroclastic fountaining and lateral transport as dense, mason, Ben G. Pyle, David M. Oppenheimer, Clive
26.
Lava
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Lava is the molten rock expelled by a volcano during an eruption. The resulting rock after solidification and cooling is called lava. The molten rock is formed in the interior of planets, including Earth. The source of the heat melts the rock within the earth is geothermal energy. When first erupted from a vent, lava is a liquid usually at temperatures from 700 to 1,200 °C. A lava flow is an outpouring of lava, which is created during a non-explosive effusive eruption. When it has stopped moving, lava solidifies to form igneous rock, the term lava flow is commonly shortened to lava. Although lava can be up to 100,000 times more viscous than water, lava can flow great distances before cooling and solidifying because of its thixotropic, explosive eruptions produce a mixture of volcanic ash and other fragments called tephra, rather than lava flows. The word lava comes from Italian, and is derived from the Latin word labes which means a fall or slide. The first use in connection with extruded magma was apparently in an account written by Francesco Serao on the eruption of Vesuvius between May 14 and June 4,1737. Serao described a flow of lava as an analogy to the flow of water. The composition of almost all lava of the Earths crust is dominated by silicate minerals, mostly feldspars, olivine, pyroxenes, amphiboles, micas, igneous rocks, which form lava flows when erupted, can be classified into three chemical types, felsic, intermediate, and mafic. These classes are primarily chemical, however, the chemistry of lava also tends to correlate with the temperature, its viscosity. Felsic or silicic lavas such as rhyolite and dacite typically form lava spines, most silicic lava flows are extremely viscous, and typically fragment as they extrude, producing blocky autobreccias. Felsic magmas can erupt at temperatures as low as 650 to 750 °C, unusually hot rhyolite lavas, however, may flow for distances of many tens of kilometres, such as in the Snake River Plain of the northwestern United States. Intermediate or andesitic lavas are lower in aluminium and silica, and usually somewhat richer in magnesium, intermediate lavas form andesite domes and block lavas, and may occur on steep composite volcanoes, such as in the Andes. Poorer in aluminium and silica than felsic lavas, and also commonly hotter, greater temperatures tend to destroy polymerized bonds within the magma, promoting more fluid behaviour and also a greater tendency to form phenocrysts. Higher iron and magnesium tends to manifest as a darker groundmass, mafic or basaltic lavas are typified by their high ferromagnesian content, and generally erupt at temperatures in excess of 950 °C
27.
San Luis Valley
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The valley is a section of the Rio Grande Rift and is drained to the south by the Rio Grande, which rises in the San Juan Mountains to the west of the valley and flows south into New Mexico. The valley is approximately 122 miles long and 74 miles wide, the San Luis Valley receives little precipitation and is made up of desert lands, but the temperatures can be very comfortable in the summer and very cold on winter nights. The San Luis Valley is the broad, generally flat, valley at the headwaters of the Rio Grande in south central Colorado, the northern portion of the San Luis Valley is an endorheic basin, which is to say that surface water does not exit this area. The southern portion is drained by the Rio Grande, there is no clear southern boundary but the term is generally used to include the San Luis Hills of southern Colorado and the Taos Plateau of northern New Mexico. About 50 miles from east to west and about 150 miles from north to south, within Colorado the San Luis Valley is generally considered to comprise six Colorado counties, Saguache, Alamosa, Rio Grande, Conejos, Costilla and Mineral. A few other counties of Colorado have some land in the Rio Grande Basin including Archuleta County, Hinsdale County, Blanca Peak is prominent in the Sierra Blanca at the southern end of the northernmost section of the mountains, which is known as the Sangre de Cristo Range. There are several passes, with elevations between 9,000 and 10,000 feet, giving access to the valley. North La Veta Pass, through the Sangre de Cristo Mountains, is used by U. S. Highway 160 and by the San Luis, other passes used historically were Medano, Mosca and Sangre de Cristo Passes. The Great Sand Dunes is a feature of the valley. It lies directly to the west of the Sangre de Cristo Mountains, the dunes can reach 750 feet high. The Great Sand Dunes National Park and Preserve is now in place to both the dunes and the numerous archeological sites found in the area. The natural valley aquifer is close to the surface in part of the valley. Elevation rises as you go north in the valley to Poncha Pass, used now by U. S. Highway 285 and historically by the narrow tracks of the Denver. Cumbres Pass is a 10,015 ft. pass between Antonito, Colorado and Chama, New Mexico, the pass is traversed by State Highway 17 and the Cumbres and Toltec Scenic Railroad. Stony Pass, sometimes spelled Stoney Pass, a wagon road to the mining camps of the San Juans, is now a jeep trail. At the north end of the valley, North Pass is the route of State Highway 114 between Saguache, Colorado and Gunnison, Colorado, bypassing the route over Cochetopa Pass. The Rio Grande follows a course through the valley from Del Norte southeastward via Alamosa to New Mexico. South of Alamosa it is joined by several streams from the west including the Alamosa River, most of the northern valley is an endorheic basin called the San Luis Closed Basin
28.
Tourism
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Tourism is travel for pleasure or business, also the theory and practice of touring, the business of attracting, accommodating, and entertaining tourists, and the business of operating tours. Tourism may be international, or within the travellers country, Tourism can be domestic or international, and international tourism has both incoming and outgoing implications on a countrys balance of payments. Today, tourism is a source of income for many countries. International tourism receipts grew to US$1.03 trillion in 2011, the ITB Berlin is the worlds leading tourism trade fair. The word tourist was used by 1772 and tourism by 1811. It is formed from the tour, which is derived from Old English turian, from Old French torner, from Latin tornare, to turn on a lathe. Tourism is an important, even vital, source of income for many regions and it also creates opportunities for employment in the service sector of the economy associated with tourism. This is in addition to goods bought by tourists, including souvenirs, in 1936, the League of Nations defined a foreign tourist as someone traveling abroad for at least twenty-four hours. Its successor, the United Nations, amended this definition in 1945 and it includes movements for all purposes. In 1981, the International Association of Scientific Experts in Tourism defined tourism in terms of particular activities chosen and undertaken outside the home, in this context, travel has a similar definition to tourism, but implies a more purposeful journey. The terms tourism and tourist are sometimes used pejoratively, to imply a shallow interest in the cultures or locations visited, by contrast, traveler is often used as a sign of distinction. The sociology of tourism has studied the values underpinning these distinctions. International tourist arrivals reached 1.035 billion in 2012, up from over 996 million in 2011, the World Tourism Organization reports the following ten destinations as the most visited in terms of the number of international travellers in 2016. International tourism receipts grew to US$1.2 trillion in 2014, based upon air traffic, the MasterCard Global Destination Cities Index reports the following cities as the top ten most popular destinations of international tourism worldwide. MasterCard reports the following cities as the top ten biggest earners on international tourism worldwide in 2015, as early as Shulgi, however, kings praised themselves for protecting roads and building waystations for travelers. During the Roman Republic, spas and coastal resorts such as Baiae were popular among the rich, pausanias wrote his Description of Greece in the 2nd century AD. In ancient China, nobles sometimes made a point of visiting Mount Tai and, on occasion, the Islamic hajj is still central to its faith and Chaucers Canterbury Tales and Wu Chengens Journey to the West remain classics of English and Chinese literature. The 10th- to 13th-century Song dynasty also saw secular travel writers such as Su Shi, under the Ming, Xu Xiake continued the practice
29.
Narrow gauge railways
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A narrow-gauge railway is a railway with a track gauge narrower than the 1,435 mm of standard gauge railways. Most existing narrow-gauge railways are between 600 mm and 1,067 mm, narrow-gauge railways also have specialized use in mines and other environments where a very small structure gauge makes a very small loading gauge necessary. Narrow-gauge railways also have general applications. Many narrow-gauge street tramways are used, particularly in Europe, where 1,000 mm metre gauge tramways are common, the earliest recorded railway is shown in the De re metallica of 1556, which shows a mine in Bohemia with a railway of about 2 ft gauge. During the 16th century, railways were mainly restricted to hand-pushed narrow-gauge lines in mines throughout Europe, during the 17th century, mine railways were extended to provide transportation above ground. These lines were industrial, connecting mines with nearby transportation points and these railways were usually built to the same narrow gauge as the mine railways from which they developed. The worlds first steam locomotive on rails, built in 1802 by Richard Trevithick for the Coalbrookdale Company, during the 1820s and 1830s, a number of industrial narrow-gauge railways in the United Kingdom used steam locomotives. In 1842, the first narrow-gauge steam locomotive outside the UK was built for the 1,100 mm gauge Antwerp-Ghent Railway in Belgium, historically, many narrow-gauge railways were built as part of specific industrial enterprises and were primarily industrial railways rather than general carriers. Some common uses for these industrial narrow-gauge railways were mining, logging, construction, tunnelling, quarrying, extensive narrow-gauge networks were constructed in many parts of the world for these purposes. For example, mountain logging operations in the 19th century often used narrow-gauge railways to transport logs from mill sites to market, significant sugarcane railways still operate in Cuba, Fiji, Java, the Philippines, and Queensland. Narrow-gauge railway equipment remains in use for the construction of tunnels. Extensive narrow-gauge railway systems served the front-line trenches of both sides in World War I and they were a short-lived military application, and after the end of the war, the surplus equipment from these created a small boom in narrow gauge railway building in Europe. Narrow-gauge railways usually cost less to build because they are lighter in construction, using smaller cars and locomotives, as well as smaller bridges, smaller tunnels. Narrow gauge is often used in mountainous terrain, where the savings in civil engineering work can be substantial. It is also used in populated areas where the potential demand is too low for broader gauge railways to be economically viable. This is the case in some of Australia and most of Southern Africa, the use of such railways has almost vanished due to the capabilities of modern trucks. In many countries, narrow gauge railways were built as feeder or branch lines to feed traffic to more important standard gauge lines, the choice was often not between a narrow-gauge railway and a standard gauge one, but between a narrow-gauge railway and none at all. Some bulk commodities, such as coal, ore, and gravel, can be transshipped, but this still incurs time penalties
30.
Durango, Colorado
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The City of Durango is the county seat and the most populous municipality of La Plata County, Colorado, United States. It is home to Fort Lewis College, the United States Census Bureau reported a population of 16,887 in the 2010 census. The city is a Home Rule Municipality, the town was organized in September 1880 to serve the San Juan mining district. The Denver and Rio Grande Railroad chose the site on the Animas River for its depot following a brief and most likely perfunctory negotiation with Animas City, according to the United States Census Bureau, the city has a total area of 6.8 square miles. According to the Köppen climate classification system, Durango has a warm-summer, the average annual precipitation is 19.33 in. As of the 2000 census, there were 13,922 people,5,492 households, the population density was 2,052.4 people per square mile. There were 5,819 housing units at a density of 857.8 per square mile. The racial makeup of the city was 86. 84% White. 5% African American,5. 51% Native American,0. 74% Asian,0. 11% Pacific Islander,4. 12% from other races, and 2. 17% from two or more races. Hispanic or Latino of any race were 10. 31% of the population,31. 8% of all households were made up of individuals and 9. 0% had someone living alone who was 65 years of age or older. The average household size was 2.23 and the family size was 2.83. In the city,16. 6% of residents are under the age of 18,26. 1% from 18 to 24,27. 2% from 25 to 44,19. 4% from 45 to 64, the median age is 29 years. For every 100 females there are 104.1 males, for every 100 females age 18 and over, there are 103.8 males. The median income for a household in the city is $34,892, males have a median income of $31,812 versus $25,022 for females. The per capita income for the city is $19,352,17. 2% of the population and 7. 3% of families live below the poverty line. 11. 2% of those younger than 18 and 8. 9% of those 65, Durango is nestled in the Animas River Valley surrounded by the San Juan Mountains. The Animas River—El Río de las Animas —runs through downtown and boasts gold medal fly fishing waters, Durango is also popular for outdoor activities like hiking, mountain biking, road biking, backpacking, slacklining, rock climbing, hunting, off-roading, year-round fishing, and golfing. Durango is near five major ski areas, including Purgatory, formerly known as Durango Mountain Resort, the city is located thirty-five miles east of Mesa Verde National Park, a UNESCO World Heritage Site best known for its Ancestral Puebloans cliff dwellings. The annual Durango Ragtime & Early Jazz Festival features noted musicians from around the country and it is held in the Strater Hotel, a historic Victorian hotel in Durango
31.
Jeep
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Jeep is a brand of American automobiles that is a division of FCA US LLC, a wholly owned subsidiary of Fiat Chrysler Automobiles. The former Chrysler Corporation acquired the Jeep brand, along with the assets of its owner American Motors. The division is headquartered in Toledo, Ohio, Jeeps current product range consists solely of sport utility vehicles and off-road vehicles, but has also included pickup trucks in the past. The original Jeep was the prototype Bantam BRC, Willys MB Jeeps went into production in 1941 specifically for the military, arguably making them the oldest four-wheel drive mass-production vehicles now known as SUVs. The Jeep became the primary light 4-wheel-drive vehicle of the United States Army, the term became common worldwide in the wake of the war. Doug Stewart notes, The spartan, cramped, and unstintingly functional jeep became the ubiquitous World War II four-wheeled personification of Yankee ingenuity and cocky, the first civilian models were produced in 1945. It inspired a number of light utility vehicles, such as the Land Rover. Many Jeep variants serving similar military and civilian roles have since been designed in other nations, only two companies responded to the request, American Bantam Car Company and Willys-Overland. The Army had set what seemed like an impossible deadline of 49 days to supply a working prototype, Willys asked for more time, but was refused. The bankrupt American Bantam Car Company had no engineering staff left on the payroll and solicited Karl Probst, after turning down Bantams initial request, Probst responded to an Army request and commenced work, initially without salary, on July 17,1940. Probst laid out plans for the Bantam prototype, known as the BRC or Bantam Reconnaissance Car. Bantams bid was submitted, complete with blueprints, on July 22, while much of the vehicle could be assembled from off-the-shelf automotive parts, custom four-wheel drivetrain components were to be supplied by Spicer. The hand-built prototype was completed in Butler, Pennsylvania, and driven to Camp Holabird, Maryland, the vehicle met all the Armys criteria except engine torque. The resulting Ford Pygmy and Willys Quad prototypes looked very similar to the Bantam BRC prototype, fifteen hundred of each of the three models were built and extensively field-tested. Delmar Barney Roos, Willys-Overlands chief engineer, made changes to meet a revised weight specification. He was thus able to use the powerful but comparatively heavy Willys Go Devil engine, the Willys version of the car would become the standardized Jeep design, designated the model MB and was built at their plant in Toledo, Ohio. The familiar pressed-metal Jeep grille was actually a Ford design feature, the Army chose Ford as the second supplier, building Jeeps to the Willys design. Willys supplied Ford with a set of plans and specifications
32.
Ghost town
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A ghost town is an abandoned village, town, or city, usually one that contains substantial visible remains. Some ghost towns, especially those that preserve period-specific architecture, have become tourist attractions, visiting, writing about, and photographing ghost towns is a minor industry. The town of Plymouth on the Caribbean island of Montserrat is a ghost town that is the de jure capital of Montserrat and it was rendered uninhabitable by volcanic ash from an eruption. The definition of a ghost town varies between individuals, and between cultures, lindsey Baker, author of Ghost Towns of Texas, defines a ghost town as a town for which the reason for being no longer exists. Some believe that any settlement with visible tangible remains should not be called a ghost town, others say, conversely, whether or not the settlement must be completely deserted, or may contain a small population, is also a matter for debate. Generally, though, the term is used in a sense, encompassing any. The American author Lambert Florins preferred definition of a ghost town was simply a shadowy semblance of a former self, a town can also be abandoned when it is part of an exclusion zone due to natural or man-made causes. Ghost towns may result when the activity or resource that created a boomtown is depleted or the resource economy undergoes a bust. Boomtowns can often decrease in size as fast as they initially grew, sometimes, all or nearly the entire population can desert the town, resulting in a ghost town. The dismantling of a boomtown can often occur on a planned basis, modular buildings can be used to facilitate the process. A gold rush would often bring intensive but short-lived economic activity to a remote village, in other cases, the reason for abandonment can arise from a towns intended economic function shifting to another, nearby place. This happened to Collingwood, Queensland in Outback Australia when nearby Winton outperformed Collingwood as a centre for the livestock-raising industry. The railway reached Winton in 1899, linking it with the rest of Queensland, the Middle East has many ghost towns that were created when the shifting of politics or the fall of empires caused capital cities to be socially or economically unviable, such as Ctesiphon. The rise of condominium investment caused for real estate bubbles also leads to a ghost town, as real estate prices rise, such examples include China and Canada, where housing is often used as an investment rather than for habitation. Railroads and roads bypassing or no longer reaching a town can create a ghost town. This was the case in many of the ghost towns along Ontarios historic Opeongo Line, some ghost towns were founded along railways where steam trains would stop at periodic intervals to take on water. Amboy, California was part of one series of villages along the Atlantic and Pacific Railroad across the Mojave Desert. River re-routing is another factor, one example being the towns along the Aral Sea, Ghost towns may be created when land is expropriated by a government and residents are required to relocate
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Mountain climbing
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The term mountaineering describes the sport of mountain climbing, including ski mountaineering. Hiking in the mountains can also be a form of mountaineering when it involves scrambling, or short stretches of the more basic grades of rock climbing. All require experience, athletic ability, and technical knowledge to maintain safety, mountaineering is often called Alpinism, especially in European languages, which implies climbing with difficulty such high and often snow and ice-covered mountains as the Alps. A mountaineer with such great skill is called an Alpinist, historically, many cultures have harbored superstitions about mountains, which they often regarded as sacred due to their proximity with heaven, such as Mount Olympus for the Ancient Greeks. In 1492 Antoine de Ville, lord of Domjulien and Beaupré, was the first to ascend the Mont Aiguille, in France, with a team, using ladders. It appears to be the first recorded climb of any technical difficulty, in 1573 Francesco De Marchi and Francesco Di Domenico ascended Corno Grande, the highest peak in the Apennine Mountains. During the Enlightenment, as a product of the new spirit of curiosity for the natural world, in 1741 Richard Pococke and William Windham made a historic visit to Chamonix. By the early 19th century many of the peaks were reached, including the Grossglockner in 1800, the Ortler in 1804, the Jungfrau in 1811, the Finsteraarhorn in 1812. In 1808 Marie Paradis became the first female to climb Mont Blanc and this inaugurated what became known as the Golden age of alpinism, with the first mountaineering club - the Alpine Club - being founded in 1857. Well-known guides of the era include Christian Almer, Jakob Anderegg, Melchior Anderegg, J. J. Bennen, Michel Croz, in the early years of the golden age, scientific pursuits were intermixed with the sport, such as by the physicist John Tyndall. In the later years, it shifted to a more competitive orientation as pure sportsmen came to dominate the London-based Alpine Club and this ascent is generally regarded as marking the end of the mountaineering golden age. By this point the sport of mountaineering had largely reached its modern form, with a body of professional guides, equipment, mountaineering in the Americas became popular in the 1800s. In North America, Pikes Peak in the Colorado Rockies was first climbed by Edwin James, though lower than Pikes Peak, the heavily glaciated Fremont Peak in Wyoming was thought to be the tallest mountain in the Rockies when it was first climbed by John C. Frémont and two others in 1842, pico de Orizaba, the tallest peak in Mexico and third tallest in North America, was first climbed by U. S. military personnel which included William F. Raynolds and a half dozen other climbers in 1848. Heavily glaciated and more technical climbs in North American were not achieved until the late 19th, in 1897 Mount Saint Elias on the Alaska-Yukon border was summitted by the Duke of the Abruzzi and party. But it was not until 1913 that Mount Mckinley, the tallest peak in North America was successfully climbed by Hudson Stuck, Mount Logan, the tallest peak in Canada was first summitted by a half dozen climbers in 1925 in an expedition that took more than two months. In 1879-1880 the exploration of the highest Andes in South America began when English mountaineer Edward Whymper climbed Chimborazo, the summit of Aconcagua was finally reached on January 14,1897 by Swiss mountaineer Matthias Zurbriggen during an expedition led by Edward FitzGerald that began in December 1896. The Andes of Bolivia were first explored by Sir William Martin Conway in 1898 and it took until the late 19th century for European explorers to penetrate Africa
34.
Wolf Creek Pass
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Wolf Creek Pass is a high mountain pass on the Continental Divide, in the San Juan Mountains of Colorado. It is the route through which U. S. Highway 160 passes from the San Luis Valley into southwest Colorado on its way to New Mexico, the pass is notable as inspiration of a C. W. McCall song. The pass is steep on either side and can be dangerous in winter. There is a truck ramp on the westbound side for truckers that lose control of their brakes. A 900-foot tunnel on the portion was opened November 5,2005. Construction was completed in the Summer of 2006, with the fully widened. The pass is home to Wolf Creek ski area located on the eastern side of the Continental Divide on Highway 160. Also on the side is one of the largest RV parks in the United States, located just a few miles west of South Fork. Wolf Creek Pass is also an attraction for tourists, as it is known for the beauty of the wilderness the highway passes through. Just west of the pass, about 15 miles east of Pagosa Springs, for decades, a major resort project proposed by Texas billionaire Red McCombs has been causing controversy in the area. The proposed resort would be situated near the summit of the pass, people familiar with the high alpine environment and water issues in the area question the wisdom of a resort style village at 10,000 elevation. McCombs has been working with the Forest Service to acquire access to the property. Following the most recent lawsuit, the reached agreement not to break ground at the site until the case is resolved in court. Proponents claim the Village would improve the economics of the region, in the song, two truckers drive an out-of-control 1948 Peterbilt down U. S. Highway 160 to Pagosa Springs—a 5, 000-foot drop in elevation. I looked at Earl and his eyes was wide His lip was curled, and his hand was froze to the wheel like a tongue to a sled in the middle of a blizzard. I says, Earl, Im not the type to complain But the time has come for me to explain That if you dont apply some brake real soon, theyre gonna have to pick us up with a stick and a spoon. The song describes the truck careening down through a tunnel and eventually into a store in Pagosa Springs. This tunnel is actually a snow shed, the song predates the only tunnel on the pass by 30 years
35.
Rio Grande
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The Rio Grande is one of the principal rivers in the southwest United States and northern Mexico. The Rio Grande begins in south-central Colorado in the United States, along the way, it forms part of the Mexico–United States border. According to the International Boundary and Water Commission, its length was 1,896 miles in the late 1980s. Depending on how it is measured, the Rio Grande is the fourth- or fifth-longest river system in North America. The river serves as part of the border between the U. S. state of Texas and the Mexican states of Chihuahua, Coahuila, Nuevo León. A very short stretch of the river serves as part of the boundary between the U. S. states of Texas and New Mexico. Since the mid–20th century, heavy consumption of farms and cities along with many large diversion dams on the river has left only 20% of its natural discharge to flow to the Gulf. Near the rivers mouth, the heavily irrigated lower Rio Grande Valley is an important agricultural region, the Rio Grande is one of 19 Great Waters recognized by Americas Great Waters Coalition. The Rio Grandes watershed covers 182,200 square miles, many endorheic basins are situated within, or adjacent to, the Rio Grandes basin, and these are sometimes included in the river basins total area, increasing its size to about 336,000 square miles. The Rio Grande rises in the part of the Rio Grande National Forest in the U. S. state of Colorado. The river is formed by the joining of several streams at the base of Canby Mountain in the San Juan Mountains and it then continues on a southerly route through the desert cities of Albuquerque, and Las Cruces to El Paso, Texas and Ciudad Juárez, Chihuahua. In the Albuquerque area, the river flows past a number of historic Pueblo villages, including Sandia Pueblo, below El Paso, it serves as part of the border between the United States and Mexico. The official river border measurement ranges from 889 miles to 1,248 miles, a major tributary, the Rio Conchos, enters at Ojinaga, Chihuahua, below El Paso, and supplies most of the water in the border segment. Other well-known tributaries include the Pecos and the smaller Devils, which join the Rio Grande on the site of Amistad Dam. Despite its name and length, the Rio Grande is not navigable by ocean-going ships, in New Mexico, the river flows through the Rio Grande rift from one sediment-filled basin to another, cutting canyons between the basins and supporting a fragile bosque ecosystem on its flood plain. From El Paso eastward, the flows through desert. Although irrigated agriculture exists throughout most of its stretch, it is extensive in the subtropical Lower Rio Grande Valley. The river ends in a small, sandy delta at the Gulf of Mexico, during portions of 2001 and 2002, the mouth of the Rio Grande was blocked by a sandbar
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Continental divide
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The endpoints where a continental divide meets the coast are not always definite, because the exact border between adjacent bodies of water is usually not clearly defined. The International Hydrographic Organizations publication Limits of Oceans and Seas defines exact boundaries of oceans, where a continental divide meets an endorheic basin, such as the Great Divide Basin of Wyoming, the continental divide splits and encircles the basin. In Africa, the most significant continental divide is the Congo-Nile Divide between the watersheds of the Nile and the Congo, passing through the area of the African Great Lakes. Between the Congo and the Sahara, a vast area drains into the endorheic Lake Chad, the interior of Antarctica receives very little precipitation, and that in the form of snow, and the continent is surrounded by the Southern Ocean. Therefore, Antarctica is not generally considered to have a continental divide, however, Australia has fewer distinct ocean boundaries and fewer prominent mountain ranges, which makes it hard to clearly and precisely define any one divide. Much of the interior of the continent drains into the endorheic Lake Eyre Basin, eurasia has various divides, depending on the definition of ocean. It was of significance in Canadian history because it marked the boundary of Ruperts Land. The Continental Divide of the Americas, also called the Great Divide, from there, it follows the crest of Mexicos Sierra Madre Occidental and extends to the tip of South America. It is crossed by the Panama Canal and by the two outlets of Isa Lake in Yellowstone National Park, the Eastern Continental Divide separates the watershed of the Gulf of Mexico from the Atlantic Ocean. It runs from the Twin Tiers of New York and Pennsylvania along the Appalachian Mountains to the tip of Florida, the city of Atlanta sits atop this divide. The Northern Divide, or Laurentian Divide, separates the watershed of the Atlantic Ocean from that of Hudson Bay, the divide traverses very flat terrain, especially in North Dakota, causing many travelers to believe the sign marking the divide is a joke. The Saint Lawrence River Divide separates the Great Lakes Basin from the rest of the Atlantic Ocean watershed, two canals cross the divide, The Chicago Sanitary and Ship Canal crosses the Chicago Portage and connects Lake Michigan to the Mississippi River watershed. The Erie Canal connects Lake Erie to the Hudson River watershed, historically there were additional canals, e. g. the Ohio and Erie Canal, but most of these are no longer in operation. These lakes in Patagonia are moraine-dammed streams that used to drain to the Atlantic rather than the Pacific before the Pleistocene glaciations, borders of the continents Boundary Treaty of 1881 between Chile and Argentina nationalatlas. gov Continental Divides in North Dakota and North America by Mark A. Gonzalez. Excellent article on Americas other continental divides, map of drainage basins in Canada
37.
San Juan River (Colorado River)
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The San Juan River is a significant tributary of the Colorado River in the southwestern United States, about 383 miles long. The river drains an area of about 24,600 square miles in southwestern Colorado, northwestern New Mexico, southeastern Utah, and a small part of northeastern Arizona. The average flow of the San Juan River at Bluff is about 2,200 cubic feet per second and the highest discharge ever measured was about 70,000 cubic feet per second on September 10,1927. The San Juan River joins the Colorado River at Lake Powell, a reservoir, and in fact the westmost miles of the San Juan River are impounded by Lake Powell. Most of the San Juan River lies in San Juan County, New Mexico and San Juan County, Utah, the San Juan River lies just a few miles northeast of the Four Corners point. The San Juan River has its source in southwestern Colorado, along the slopes of the San Juan Mountains. The largest tributary of the San Juan is the Animas River, followed by the Piedra, the San Juan drains an arid region of North America, and along its length it is very often the only significant source of fresh water. The San Juan River is the only significant stream in the parts of the Navajo Indian Reservation that lie in New Mexico, Colorado, and Utah. Aside from Lake Powell, the only impoundment of water along the San Juan River is at Navajo Lake, formed by the Navajo Dam in eastern San Juan County. Significant towns located along the San Juan River are Pagosa Springs, Colorado, the San Juan River flows into the Colorado River at the center of Lake Powell. In general, the San Juan River provides good fishing in its warm, slow, one section deserves special mention for its fly fishing allure, the 4.25 miles just below Navajo Dam in northwest New Mexico, near the small town of Aztec. This stretch, known as the Miracle Mile, is among the most hallowed trout fishing waters in North America, the water released from the bottom of the dam is clear and cold, rich in nutrients, and flows are relatively stable. The Utah section of the San Juan River is a recreational destination. Whitewater rafting, fishing, hiking and camping are all popular in the summer months. For travelers, the San Juan River also provides a look at Native American history in the form of ruins. The banks of the San Juan contain diverse animal and plant life, the San Juan River from Bluff, Utah, to Lake Powell is managed by the Bureau of Land Managements Monticello Field Office. Permits are generally required for any type of recreation on the river, List of rivers of Colorado List of rivers of New Mexico List of rivers of Utah List of tributaries of the Colorado River San Juan Expedition Media related to San Juan River at Wikimedia Commons
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Dolores River
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The Dolores River is a tributary of the Colorado River, approximately 241 miles long, in the U. S. states of Colorado and Utah. The river drains a rugged and arid region of the Colorado Plateau west of the San Juan Mountains and its name derives from the Spanish El Rio de Nuestra Señora de Dolores, River of Our Lady of Sorrows. The river was explored and possibly named by Juan Maria Antonio Rivera during an 1765 expedition from Santa Fe, the mean annual flow of the Dolores prior to damming was approximately 1,200 cu ft/s, but due to diversions it has been reduced to about 600 cu ft/s. The Dolores River rises in a meadow called Tin Can Basin, near 12, 520-foot Hermosa Peak in the San Miguel Mountains, in Dolores County, the headwaters are located about 5 miles south of Lizard Head Pass in the San Juan National Forest. The river flows southwest in a canyon past Rico, receiving the West Dolores River, formed by McPhee Dam, the reservoir is about 10 miles long and diverts flows of the upper Dolores River for irrigation. Downstream from McPhee Dam, the river re-enters Dolores County and carves the Dolores River Canyon and this section of the Dolores River is noted for its exposed sedimentary strata, desert wildlife, and during years of heavy snowmelt for its whitewater. Near Egnar the river crosses into San Miguel County and then from there into Montrose County, continuing north, the Dolores cuts across the Paradox Valley which runs in an unusual transverse direction to the river. Immediately below Paradox Valley it is joined by the San Miguel River, its main tributary, due to diversions on the main stem, the San Miguel is typically the same size as the Dolores if not larger, providing most of the flow below the confluence in dry years. Below the confluence with the San Miguel, the Dolores enters Mesa County, flowing north-northwest past Gateway, the last segment of the river, entirely within Grand County, joins the Colorado near the historic Dewey Bridge, about 30 miles above Moab. The United States Geological Survey has operated a stream gage at Cisco from 1950 to the present, for the 36-year period December 1950 to September 1986, the river flow at Cisco averaged 845 cubic feet per second. By contrast, in the 27 years from October 1986 to October 2013, the ancestral Dolores River is believed to have flowed south to join the San Juan River near the Four Corners in what is now northwestern New Mexico. The Dolores Canyon exposes rocks ranging from 300-million-year-old Pennsylvanian limestone to the 140-million-year-old Entrada sandstone deposited during the Jurassic, a cap of Cretaceous Dakota sandstone forms most of the upper rim of the canyon. The Dolores is dammed at McPhee Reservoir near Cortez, Colorado to irrigate about 61,660 acres of plateau land. The dam and diversion canals are operated by the Bureau of Reclamation as the Dolores Project, the construction of the dam allowed local farmers to extend the irrigation season through September whereas natural river flows would have been insufficient by July or August. Before the dam was built, irrigators diverted nearly the entire flow of the river, releases from McPhee Dam are a controversial topic. This fact aggrieves recreational boaters, who claim it is difficult for anyone, the San Juan Citizens Alliance has worked to start a dialogue between Dolores River stakeholders in the hopes of shifting release policy to one that allows for greater, planned releases. The Dolores is navigable by rafts and kayaks from McPhee Reservoir to its confluence with the Colorado, when water is restricted from the reservoir it may be possible to boat down stream from the San Miguel River. However, the river is used for irrigation and during low water years can be wholly unnavigable
39.
Gunnison River
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The Gunnison River is a tributary of the Colorado River,164 miles long, in the Southwestern state of Colorado. It is the fifth largest tributary of the Colorado River, with a flow of 4,320 cu ft/s. The Gunnison River is formed by the confluence of Taylor and East rivers at Almont in eastern Gunnison County. Just past the town of Gunnison, the river begins to swell into the expanse of Blue Mesa Reservoir, a 36-mile-long reservoir formed by Blue Mesa Dam, where it receives the Lake Fork of the Gunnison. Just downstream it is dammed again to form Morrow Point Reservoir, the reservoirs produce hydroelectric power and supply water for the surrounding areas for both municipal and irrigation use. The reservoirs are the part of the Black Canyon of the Gunnison, one of the longest, narrowest. Below Crystal Dam it begins to roar through massive cataracts and flows through the deepest part of the gorge, at the outlet of the canyon it receives the North Fork River, then downstream near Delta, Colorado is joined by the Uncompahgre River. The Gunnison River ranges in width from 100 to 1,000 feet and 3 to 50 feet in depth, the rivers powerful current and many rapids make upstream travel nearly impossible. It is navigable for small craft throughout its course and by larger boats below the Black Canyon, parts of the Black Canyon are non-navigable to any sorts of craft because of giant cataracts. Navigation through the canyon is dangerous and for experienced boaters only. It was again seen in 1776 by Silvestre Vélez de Escalante, at the time the Spanish name for the river was Rio de San Javier, and the Native American name was Tomichi. Escalante noted that Rivera thought it was the great Rio del Tizon, through the mid-1800s, the river was variously named the Eagle, Eagle Tail, South Fork of the Grand, Grande, and Grand River. Exploration reports and published maps in the 1850s and 1860s most commonly referred to the river as the Grand River, the upper section of the Gunnison River is designated as gold medal water and wild trout water. The designation begins 200 yards below the Crystal Dam and stretches through the Gunnison Gorge to the confluence of the North Fork, part of the rivers water is diverted to irrigate the Uncompahgre Valley via the 5-mile-long Gunnison Tunnel, which was built between 1905 and 1909. Dams on the river include Blue Mesa Dam, Morrow Point Dam, List of rivers of Colorado List of tributaries of the Colorado River Black Canyon National Park, Colorado. Gunnison River Information and Fishing Report
40.
Colorado River (U.S.)
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The Colorado River is one of the principal rivers of the Southwestern United States and northern Mexico. The 1, 450-mile-long Colorado River drains an expansive, arid watershed that encompasses parts of seven U. S. starting in the central Rocky Mountains in the U. S. After entering Mexico, the Colorado approaches the mostly dry Colorado River Delta at the tip of the Gulf of California between Baja California and Sonora. Known for its dramatic canyons, whitewater rapids, and eleven U. S. National Parks, the Colorados large flow and steep gradient are used for generating hydroelectric power, and its major dams regulate peaking power demands in much of the Intermountain West. Intensive water consumption has dried up the lower 100 miles of the river, beginning with small bands of nomadic hunter-gatherers, Native Americans have inhabited the Colorado River basin for at least 8,000 years. Most native peoples that inhabit the basin today are descended from groups that settled in the region beginning about 1,000 years ago. Europeans first entered the Colorado Basin in the 16th century, when explorers from Spain began mapping and claiming the area, early contact between Europeans and Native Americans was generally limited to the fur trade in the headwaters and sporadic trade interactions along the lower river. After most of the Colorado River basin became part of the U. S. in 1846, several expeditions charted the Colorado in the mid-19th century – one of which, led by John Wesley Powell, was the first to run the rapids of the Grand Canyon. American explorers collected valuable information that would later be used to develop the river for navigation, lesser numbers settled in the upper basin, which was the scene of major gold strikes in the 1860s and 1870s. Large engineering works began around the start of the 20th century, with guidelines established in a series of international. The U. S. federal government was the driving force behind the construction of dams and aqueducts in the river system, although many state. Most of the dams in the river basin were built between 1910 and 1970, the system keystone, Hoover Dam, was completed in 1935. The Colorado is now considered among the most controlled and litigated rivers in the world, as demands for Colorado River water continue to rise, the level of human development and control of the river continues to generate controversy. The Colorado begins at La Poudre Pass in the Southern Rocky Mountains of Colorado, after a short run south, the river turns west below Grand Lake, the largest natural lake in the state. As it flows southwest, it gains strength from many tributaries, as well as larger ones including the Blue, Eagle. In a few areas, such as the marshy Kawuneeche Valley near the headwaters, arcing northwest, the Colorado begins to cut across the eponymous Colorado Plateau, a vast area of high desert centered at the Four Corners of the southwestern United States. In Utah, the Colorado flows primarily through the slickrock country and this is one of the most inaccessible regions of the continental United States. Here, the San Juan River, carrying runoff from the slope of Colorados San Juan Mountains, joins the Colorado from the east. S
41.
San Juan National Forest
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The San Juan National Forest is a U. S. National Forest covering over 1,878,846 acres in western Colorado. The forest occupies land in Archuleta, Conejos, Dolores, Hinsdale, La Plata, Mineral, Montezuma, Rio Grande, San Miguel and it borders the Uncompahgre National Forest to the north and the Rio Grande National Forest to the east. The forest covers most of the portion of the San Juan Mountains west of the Continental Divide. The forest contains two alpine wilderness areas, the Weminuche and South San Juan, as well as the Piedra Area, the Durango and Silverton Narrow Gauge Railroad passes through the National Forest. Theodore Roosevelt created the forest by proclamation on June 3,1905, Forest headquarters are located in Durango, Colorado. There are local district offices in Bayfield, Dolores. President Barack Obama designated part of the forest as Chimney Rock National Monument by proclamation on September 21,2012, there are three officially designated wilderness areas lying within San Juan National Forest that are part of the National Wilderness Preservation System. All of them extend partially into neighboring National Forests, lizard Head Wilderness South San Juan Wilderness Weminuche Wilderness Hermosa Wilderness List of largest United States National Forests List of U. S. National Forests San Juan National Forest
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Uncompahgre National Forest
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Uncompahgre National Forest is a U. S. National Forest covering 955,229 acres in parts of Montrose, Mesa, San Miguel, Ouray, Gunnison, San Juan, and Delta Counties in western Colorado. Only its headquarters is in Delta County, in the city of Delta and it borders the San Juan National Forest to the south. Within the national forest boundaries can be found the arid Uncompahgre Plateau, the forest contains three alpine wilderness areas, Uncompahgre, Mount Sneffels and Lizard Head. The Uncompahgre National Forest is managed jointly with the Grand Mesa, there are local ranger district offices located in Montrose and Norwood. The varied climate, sparse population, and abundance of sun make the Uncompahgre National Forest popular with jeepers, atvers, sight seers, a common recreational activity within the Forest boundaries is scenic driving, thanks in part to the Million Dollar Highway. There are several roads within the Uncompahgre, some are mining roads left from the 1800s mineral rush. Paved roads include the San Juan Skyway, Alpine Loop, the Unaweep-Tabeguache Scenic and Historic Byway and Owl Creek Pass, there are three officially designated wilderness areas lying within Uncompahgre National Forest that are part of the National Wilderness Preservation System. One of them mostly in a neighboring National Forest, while another one extends onto land that is managed by the Bureau of Land Management. Lizard Head Wilderness Mount Sneffels Wilderness Uncompahgre Wilderness Grand Mesa Scenic and Historic Byway Grand Mesa, Uncompahgre and Gunnison National Forests GORP GORP list of campgrounds
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