<P> Beginning in the late 19th century with the state's mining boom (including the Bingham Canyon Mine, among the world's largest open pit mines), companies attracted large numbers of immigrants with job opportunities . Since the days of the Utah Territory mining has played a major role in Utah's economy . Historical mining towns include Mercur in Tooele County, Silver Reef in Washington County, Eureka in Juab County, Park City in Summit County and numerous coal mining camps throughout Carbon County such as Castle Gate, Spring Canyon, and Hiawatha . </P> <P> These settlements were characteristic of the boom and bust cycle that dominated mining towns of the American West . During the early part of the Cold War era, uranium was mined in eastern Utah . Today mining activity still plays a major role in the state's economy . Minerals mined in Utah include copper, gold, silver, molybdenum, zinc, lead, and beryllium . Fossil fuels including coal, petroleum, and natural gas continue to play a large role in Utah's economy, especially in the eastern part of the state in counties such as Carbon, Emery, Grand, and Uintah . </P> <P> In 2007, nine people were killed at the Crandall Canyon Mine collapse . </P> <P> On March 22, 2013, one miner died and another was injured after they became trapped in a cave - in at a part of the Castle Valley Mining Complex, about 10 miles west of the small mining town of Huntington in Emery County . </P>

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