Hoover Dam

Image Gallery NICE VIEW: A visitor's center built into the Black Canyon at Hoover Dam includes a rooftop overlook. Tom & Joanne O'Toole

Let's get rid of the big myth about Hoover Dam right now. There are no bodies buried in the concrete of this colossal structure that holds back the Colorado River. Completed 70 years ago this month, the dam does, however, feature a number of plaques and a monument near its visitor's center that honor the men who built it - including the 110 workers who died in the process.

Straddling the state border of Arizona and Nevada, this water conservation and hydroelectric power plant is one of the outstanding engineering accomplishments of the 20th century. It rises more than 726 feet from bedrock, is 660 feet thick at the base, 45 feet wide at top, and its crest stretches 1,244 feet across the canyon. More than five miles of maintenance and inspection tunnels are built into the structure. (Many are lined with ceramic tile and American Indian art designs.)

Depression-era dam

Black Canyon was selected as the best site for the dam because it was narrow and had high, strong, sheer walls. With the Great Depression sweeping the country, finding men eager to do the backbreaking and often-dangerous work was no problem. Work officially began in May 1931.

By 1933, the concrete began to be poured - and it would flow day and night for two years. When it was finished, more than 3.25 million cubic yards of hard concrete were in place.

Bid at just under $49 million - the largest construction contract led by the federal government up to that time - Hoover Dam was completed in four and a half years - two and a half years ahead of schedule. (Imagine that happening today!) The overall cost of the project, including the dam, power plants and related structures, was $165 million.

The multipurpose dam was built to harness the Colorado River for flood control, navigation, irrigation, water storage and power. In the bargain, the project was to be self-supporting, financed entirely through the sale of the hydroelectric power generated

Popular attraction

Just 30 miles south of Las Vegas, Hoover Dam is the third most popular tourist attraction in the United States under the control of the federal government. The two-lane road from Las Vegas to the dam snakes through a desert landscape that hasn't changed in thousands of years.

Visiting motorists will crest a knoll and then face a huge oasis - Lake Mead, a man-made body of water that extends more than 110 miles upstream from the dam.

Tourists can learn about the dam, its history and construction, when they visit a visitor's center built into the Nevada side of the canyon wall. The center has a rooftop overlook and, for a fee, visitors can take a tour that departs from the center.