The Hoover Dam was constructed between 1921 and 1935 at a cost of $49 million. It stands 726 feet tall and required over 3.25 million cubic yards of concrete. To prevent cracking as the concrete cured, it was poured in stages with steel pipes circulating cold water. This created Lake Mead behind the dam. When completed in 1935, it was the largest dam in the world and harnesses the Colorado River to generate electricity through 17 turbines.

1. The Hoover Dam 1921-1935

2. Construction of the Hoover dam At the time the dam cost 49$ million to construct. The dam is 726 feet high, 660 ft thick, and is 1244 ft long. Hoover Dam required over 3,250,000 cubic yards of concrete plus another million for the power plant, intake towers and other support structures.

3. How the power plant makes electricity. Inside are 17 turbines--nine on the Arizona side and eight on the Nevada side--plus two small generators used to create power for the plant itself. The force of the water spins the turbines, which spin magnets past coils of copper wire. The act of spinning the magnets past the copper coils creates the electricity.

4. How the Hoover dam was constructed Over 3,250,000 cubic yards of concrete was used to build the dam. To simply pour the dam all at once would have caused it to eventually crack and collapse under the weight of its own curing. This problem was solved by pouring the concrete in interlocking stages, one block at a time. The cooling of the concrete was further helped by putting steel pipes into each poured block that circulated ice water through them until the cement was cure

6. Creation of lake Mead The dam is the separator between lake mead and the Colorado river. This lake was made when the dam was put in place and dammed up the Colorado river.

7. Completion of the dam With the dam's building complete, in 1935 Hoover Dam became the largest dam in the world.

8. How Does the Hoover Dam Make Electricity? | eHow.com http://www.ehow.com/how-does_5164758_hoover-dam-make-electricity.html#ixzz1EhZyjEyX job, it is still curing, getting harder and emitting heat.Read more: How Was the Hoover Dam Built? | eHow.com http://www.ehow.com/how-does_5245117_hoover-dam-built_.html#ixzz1EtDENQkz http://users.humboldt.edu/ogayle/HooverConcretePouring.jpg&imgrefurl=http://users.humboldt.edu/ogayle/hist383/Depression-WorldWarII.html&usg=__4iT1DmVJZ3cmZCuO1i0LLP1gUh4=&h=600&w=750&sz=134&hl=en&start=0&zoom=1&tbnid=aYBL75joX5XkEM:&tbnh=129&tbnw=162&ei=FXlmTZHmLoa8lQeRo6D_AQ&prev=/images%3Fq%3Dpouring%2Bthe