<P> This history of Las Vegas covers both the city of Las Vegas, Nevada, and the Las Vegas Valley . </P> <P> The name Las Vegas was given to the area in 1821 by Rafael Rivera, a member of the Antonio Armijo trading party that was traveling to Los Angeles, and stopped for water there on the Old Spanish Trail from New Mexico . At that time, several parts of the valley contained artesian wells surrounded by extensive green areas; Las Vegas means the meadows in Spanish . The flows from the wells fed the Las Vegas Wash, which runs to the Colorado River . </P> <P> Urbanisation began in 1902, when a railroad linking Los Angeles and Salt Lake City attracted many farmers to the area, and fresh water was piped into the settlement . In 1911, the city was incorporated as part of Clark County . In 1931 work started on the Boulder Dam (now the Hoover Dam), bringing a huge influx of young male workers, for whom theatres and casinos were built, largely by the Mafia . Electricity from the dam also enabled the building of many new hotels along the Strip . The arrival of Howard Hughes in 1966 did much to offset mob influence, and helped turn Las Vegas into more of a family tourist centre, now classified as a Megaresort . </P> <P> The prehistoric landscape of the Las Vegas Valley and most of Southern Nevada was once a marsh with water and vegetation . The rivers that created the marsh eventually went underground, and the marsh receded . The valley then evolved into a parched, arid landscape that only supported the hardiest animals and plants . </P>

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