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Boulder Canyon Project
Hoover Dam is a concrete arch-gravity dam in the Black Canyon of the Colorado River, on the border between the U.S. states of Nevada and Arizona. It was constructed between 1931 and 1936 during the Great Depression and was dedicated on September 30, 1935, by President Franklin D. Roosevelt. Its construction was the result of a massive effort involving thousands of workers, and cost over one hundred lives. It was referred to as Hoover Dam after President Herbert Hoover in bills passed by Congress during its construction; it was named Boulder Dam by the Roosevelt administration. The Hoover Dam name was restored by Congress in 1947. Since about 1900, the Black Canyon and nearby Boulder Canyon had been investigated for their potential to support a dam that would control floods, provide irrigation water and produce hydroelectric power. In 1928, Congress authorized the project. The winning bid to build the dam was submitted by a consortium named Six Companies, Inc., which bega ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ansel Adams
Ansel Easton Adams (February 20, 1902 – April 22, 1984) was an American landscape photographer and environmentalist known for his black-and-white images of the American West. He helped found Group f/64, an association of photographers advocating "pure" photography which favored sharp focus and the use of the full tonal range of a photograph. He and Fred Archer developed an exacting system of image-making called the Zone System, a method of achieving a desired final print through a deeply technical understanding of how tonal range is recorded and developed during exposure, negative development, and printing. The resulting clarity and depth of such images characterized his photography. Adams was a life-long advocate for environmental conservation, and his photographic practice was deeply entwined with this advocacy. At age 12, he was given his first camera during his first visit to Yosemite National Park. He developed his early photographic work as a member of the Sierra C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Great Depression In The United States
In the United States, the Great Depression began with the Wall Street Crash of October 1929 and then spread worldwide. The nadir came in 1931–1933, and recovery came in 1940. The stock market crash marked the beginning of a decade of high unemployment, poverty, low profits, deflation, plunging farm incomes, and lost opportunities for economic growth as well as for personal advancement. Altogether, there was a general loss of confidence in the economic future. The usual explanations include numerous factors, especially high consumer debt, ill-regulated markets that permitted overoptimistic loans by banks and investors, and the lack of high-growth new industries. These all interacted to create a downward economic spiral of reduced spending, falling confidence and lowered production. Industries that suffered the most included construction, shipping, mining, logging, and agriculture. Also hard hit was the manufacturing of durable goods like automobiles and appliances, whose purc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Power Transmission
Electric power transmission is the bulk movement of electrical energy from a generating site, such as a power plant, to an electrical substation. The interconnected lines that facilitate this movement form a ''transmission network''. This is distinct from the local wiring between high-voltage substations and customers, which is typically referred to as electric power distribution. The combined transmission and distribution network is part of electricity delivery, known as the electrical grid. Efficient long-distance transmission of electric power requires high voltages. This reduces the losses produced by strong currents. Transmission lines use either alternating current (HVAC) or direct current (HVDC). The voltage level is changed with transformers. The voltage is stepped up for transmission, then reduced for local distribution. A wide area synchronous grid, known as an "interconnection" in North America, directly connects generators delivering AC power with the same rela ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Southern Pacific Railroad
The Southern Pacific (or Espee from the railroad initials- SP) was an American Class I railroad network that existed from 1865 to 1996 and operated largely in the Western United States. The system was operated by various companies under the names Southern Pacific Railroad, Southern Pacific Company and Southern Pacific Transportation Company. The original Southern Pacific began in 1865 as a land holding company. The last incarnation of the Southern Pacific, the Southern Pacific Transportation Company, was founded in 1969 and assumed control of the Southern Pacific system. The Southern Pacific Transportation Company was acquired in 1996 by the Union Pacific Corporation and merged with their Union Pacific Railroad. The Southern Pacific legacy founded hospitals in San Francisco, Tucson, and Houston. In the 1970s, it also founded a telecommunications network with a state-of-the-art microwave and fiber optic backbone. This telecommunications network became part of Sprint, a compa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salton Sea
The Salton Sea is a shallow, landlocked, highly saline body of water in Riverside and Imperial counties at the southern end of the U.S. state of California. It lies on the San Andreas Fault within the Salton Trough that stretches to the Gulf of California in Mexico. Over millions of years, the Colorado River has flowed into the Imperial Valley and deposited alluvium (soil), creating fertile farmland, building up the terrain, and constantly moving its main course and river delta. For thousands of years, the river has alternately flowed into the valley, or diverted around it, creating either a saline lake called Lake Cahuilla, or a dry desert basin, respectively. When the Colorado River flows into the valley, the lake level depends on river flows and the balance between inflow and evaporative loss. When the river diverts around the valley, the lake dries completely, as it did around 1580. Hundreds of archaeological sites have been found in this region, indicating possibly long-ter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Imperial Valley
, photo = Salton Sea from Space.jpg , photo_caption = The Imperial Valley below the Salton Sea. The US-Mexican border runs diagonally across the lower left of the image. , map_image = Newriverwatershed-1-.jpg , map_caption = Map of Imperial Valley , coordinates = , location = California, United States , direction = Northwest-Southeast , length = , towns = Brawley, Calexico, El Centro, Imperial , traversed = Interstate 8, State Route 78, State Route 86, State Route 111 The Imperial Valley ( es, Valle de Imperial or ''Valle Imperial'') of Southern California lies in Imperial and Riverside counties, with an urban area centered on the city of El Centro. The Valley is bordered by the Colorado River to the east and, in part, the Salton Sea to the west. Farther west lies the San Diego and Imperial County border. To the north is the Coachella Valley region of Riverside County, which together with Imperial Valley form the Salton Trough, or the Cahuilla Basin, also the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alamo Canal
The Alamo Canal ( es, Canal del Álamo) was a long waterway that connected the Colorado River to the head of the Alamo River. The canal was constructed to provide irrigation to the Imperial Valley. A small portion of the canal was located in the United States but the majority of the canal was located in Mexico. The Alamo Canal is also known as the Imperial Canal. Planning and construction Historically, the Colorado River flowed to the Gulf of California, however in times of the spring floods the Colorado River would overflow its banks and also drain into the Alamo River. Flow from the Alamo River then drained to the Salton Sink area of the Colorado Desert. Such overflow had been observed in 1884, 1891, 1892, and 1895. In the mid- to late-Nineteenth Century several individuals, most notably O. M. Wozencraft, proposed irrigating the Salton Sink by diverting a controlled gravity-fed flow of the Colorado River through the existing dry Alamo River bed. The Alamo Canal was the f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mike O'Callaghan–Pat Tillman Memorial Bridge
The Mike O'Callaghan–Pat Tillman Memorial Bridge is an arch bridge in the United States that spans the Colorado River between the states of Arizona and Nevada. The bridge is located within the Lake Mead National Recreation Area approximately southeast of Las Vegas, and carries Interstate 11 and U.S. Route 93 over the Colorado River. Opened in 2010, it was the key component of the Hoover Dam Bypass project, which rerouted US 93 from its previous routing along the top of Hoover Dam and removed several hairpin turns and blind curves from the route. It is jointly named for Mike O'Callaghan, Governor of Nevada from 1971 to 1979, and Pat Tillman, an American football player who left his career with the Arizona Cardinals to enlist in the United States Army and was killed in Afghanistan in 2004 by friendly fire. As early as the 1960s, officials identified the US 93 route over Hoover Dam to be dangerous and inadequate for projected traffic volumes. From 1998 to 2001, officials from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Las Vegas
Las Vegas (; Spanish for "The Meadows"), often known simply as Vegas, is the 25th-most populous city in the United States, the most populous city in the state of Nevada, and the county seat of Clark County. The city anchors the Las Vegas Valley metropolitan area and is the largest city within the greater Mojave Desert. Las Vegas is an internationally renowned major resort city, known primarily for its gambling, shopping, fine dining, entertainment, and nightlife. The Las Vegas Valley as a whole serves as the leading financial, commercial, and cultural center for Nevada. The city bills itself as The Entertainment Capital of the World, and is famous for its luxurious and extremely large casino-hotels together with their associated activities. It is a top three destination in the United States for business conventions and a global leader in the hospitality industry, claiming more AAA Five Diamond hotels than any other city in the world. Today, Las Vegas annually ranks as one ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Six Companies, Inc
Six Companies, Inc. was a joint venture of construction companies that was formed to build the Hoover Dam on the Colorado River in Nevada and Arizona. They later built Parker Dam, a portion of the Grand Coulee Dam, the Colorado River Aqueduct across the Mojave and Colorado Deserts to urban Southern California, and many other large projects. Hoover Dam On January 10, 1932, the Bureau of Reclamation made bid documents for the Hoover Dam construction project available to interested parties at $5 a copy (equivalent to $ in ). The government would provide the materials, and the contractor was to prepare the site and build the dam. The dam was described in minute detail, covering 100 pages of text and 76 drawings. A $2 million (equivalent to $ in ) bid bond was to accompany each bid. The winner would have to post a $5 million (equivalent to $ in ) performance bond. The contractor would have seven years to build the dam, or penalties would ensue. Because of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydroelectric Power
Hydroelectricity, or hydroelectric power, is electricity generated from hydropower (water power). Hydropower supplies one sixth of the world's electricity, almost 4500 TWh in 2020, which is more than all other renewable sources combined and also more than nuclear power. Hydropower can provide large amounts of low-carbon electricity on demand, making it a key element for creating secure and clean electricity supply systems. A hydroelectric power station that has a dam and reservoir is a flexible source, since the amount of electricity produced can be increased or decreased in seconds or minutes in response to varying electricity demand. Once a hydroelectric complex is constructed, it produces no direct waste, and almost always emits considerably less greenhouse gas than fossil fuel-powered energy plants. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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