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The Hoover Dam, built in 1931, is named after former President Herbert Hoover. The Colorado River made the dam necessary, which begins high in the Rocky Mountains. Heavy snow falls on the Rocky Mountains. The snow is so deep in some areas, but the snow does melt. Cold ice water travels down the mountains and forms several rivers. These rivers link(连接) together and form the beginning of the Colorado River which flows through, or provides water for the states of Wyoming, Colorado, Utah, New Mexico, Arizona, Nevada and California. Then it crosses the border(边界) into Mexico.
The Colorado River has always been powerful. It created the huge Grand Canyon(大峡谷). The water cut hundreds of metres deep into the desert floor of Arizona. The Grand Canyon was cut into the desert floor beginning thousands of years ago. But the power of this river has been demonstrated in more modern times. Between 1905 and 1907, the Colorado River caused great amounts of flooding in parts of Arizona and California. In two years of flooding, the Colorado River filled the ancient lake called the Salton Sea. The flooding also flooded homes, towns and farming areas. Many people were forced to flee their homes.
