$~~~~$Located in Black Canyon straddling the border between Nevada and Arizona in the southwestern region of the United States, Hoover Dam is named one of the Top 10 Construction Achievements of the 20th century. The dam, constructed between 1931 and 1936, was the largest of its kind at the time. Its construction was the result of a massive effort involving thousands of workers and cost over one hundred lives.

$~~~~$Since about 1900, the Black Canyon and nearby Boulder Canyon had been investigated for their potential to support a dam that would control floods, provide irrigation water, and produce hydroelectric power. In 1928, the US Congress authorized the project. The winning bid to build the dam was submitted by Six Companies, Inc. However, such a large concrete structure had never been built before, and some of the techniques were unproven. The extreme summer heat and lack of facilities near the site also presented tremendous difficulties. Nevertheless, Six Companies turned over the finished dam to the federal government on March 1, 1936, more than two years ahead of schedule.

$~~~~$The initial design of the dam, which was more concerned with the dam’s functionality than its exterior, was criticized by many as being too plain and unremarkable for a project of such immense scale. So Gordon B. Kaufmann, the architect who was brought in to redesign the exterior, greatly streamlined the design and applied an elegant Art Deco style to the entire project. Allen Tupper True, an American illustrator, was also hired to handle the design and decoration of the walls and floors of the new dam. He integrated into his design the images and colors based on Native American visions of rain, lightning, clouds, and animals, thereby creating symbolic patterns which appear both ancient and modern.

$~~~~$Today, Hoover Dam has become a national historic landmark. Standing at more than 725 feet above the Colorado River, the highest concrete dam in the Western Hemisphere continues to draw crowds 85 years after its creation, attracting more than a million visitors a year.