The Hoover Dam weighs more than 6.5 million tons.

The Hoover Dam is one of the tallest concrete dams ever built and it created one of the largest manmade lakes in the United States. At 726.4 feet tall, it took 200 engineers from several consulting firms and the Bureau of Reclamation to design the dam. It has 3,125,000 cubic yards of concrete and weighs more than 6.6 million tons! Construction of the dam, power plant, and related works took five years to build and was finished two years ahead of schedule. The reservoir created can hold enough water to cover the entire state of Pennsylvania with water one foot deep. 

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