Hoover Dam Bypass Bridge Prepares For Travelers

Enlarge this image toggle caption Courtesy of Federal Highway Administration Courtesy of Federal Highway Administration

The Hoover Dam is an American landmark, perhaps the quintessential public works project, built during the Great Depression to provide power and irrigation to the West.

Now, the Hoover Dam has company: a new bypass bridge -- another engineering marvel just downstream, spanning the Colorado River between Nevada and Arizona.

Enlarge this image toggle caption Courtesy of Federal Highway Administration Courtesy of Federal Highway Administration

The bridge, almost 900 feet above the Colorado River, will open to traffic sometime this week. Highway officials are refraining from announcing the day to avoid a crush of vehicles trying to be the first to cross.

One of the highest bridges in the world, the Hoover Dam bypass bridge rises 726 feet above the bedrock. It has the longest single concrete arch in the Western Hemisphere -- a semicircle that echoes the graceful curve of the dam upstream. The arch, curving downward on either side, supports the four-lane roadway on top. It took five years for it to literally come together, section by section from either side.

Erik Dozier worked on the steel cables that held molds for the concrete sections as they were being poured. He says every part of the construction process was a thrill for him.

"I've been excited all morning, couldn't sleep last night. And [I'm] looking forward to seeing a lot of friends I haven't seen in a while and seeing the finished product," Dozier said on the morning of a special sneak peek of the completed bridge for workers and officials.

Hide caption The Hoover Dam is the highest concrete arch dam in the United States, measuring 726 feet high and 1,244 feet long along the crest of the dam. Previous Next AP/NPR

Hide caption Construction of the Hoover Dam began in 1930 in Black Canyon on the Colorado River. The site sits on the border between northwest Arizona and southeast Nevada. Previous Next Getty Images/NPR

Hide caption The largest federally funded project of its time, the Hoover Dam's construction efforts employed more than 20,000 workers, hired by the Bureau of Reclamation during the Great Depression. Previous Next AP/NPR

Hide caption The Hoover Dam was built in interlocking blocks of concrete rather than a single block. This 1935 photo shows a crack in the upper center of the dam left open for cooling and settling of the concrete. Previous Next AP/NPR

Hide caption A cable railway runs over the Hoover Dam while the structure is still under construction. Concrete used to construct the dam was transported in buckets by cranes operated by some of the project's highest paid workers, who earned $1.25 per hour. Previous Next Getty Images/NPR

Hide caption President Franklin D. Roosevelt (top, center) dedicated the dam on Sept. 20, 1935, as the "Boulder Dam." In 1947, the dam was renamed in honor of President Herbert Hoover, who led the effort to create the dam while he was Commerce Secretary. Previous Next AP/NPR

Hide caption Taken in 1939, this aerial view of the Hoover Dam also shows Lake Mead (lower right), one of the world's largest manmade lakes, formed by the dam. The bank to the right of the Colorado River is Nevada, and on the left is Arizona. Previous Next AP/NPR

Hide caption This 1948 photo shows traffic crossing the Arizona border on U.S. Highway 93, which will continue along the top of the Hoover Dam until the new Mike O'Callaghan-Pat Tillman Memorial Bridge opens to traffic. Previous Next AP/NPR

Hide caption The Hoover Dam harnesses water from the Colorado River for use in power generation. Previous Next Getty Images/NPR 1 of 9 i View slideshow

During construction, many of the workers spent their days perched high in the air. One worker was killed during construction and a support tower collapsed during a storm.

The completion of the bridge's arch was the most exciting moment for engineering manager Terry Pawlawski, who calls the Hoover Dam bypass bridge a "once-in-a-lifetime project."

At the time of its construction during the Great Depression, the Hoover Dam was also hailed as a monumental effort. Standing on top of the dam, tourists Jim Setser and Floyd Irwin marveled at the bridge about 1,500 feet away.

"It's incredible. We're from Boston, and it's the first time we've ever seen a bridge that big," Setser says.

The structure is officially called the Mike O'Callaghan-Pat Tillman Memorial Bridge, named after a former governor of Nevada and the Arizona Cardinals football player and soldier who was killed by friendly fire in Afghanistan.

Enlarge this image toggle caption Mark Ralston/AFP/Getty Images Mark Ralston/AFP/Getty Images

After opening to traffic, the bridge will become the shortest route between Phoenix and Las Vegas -- a title that for the past 75 years has belonged to the two-way road over the top of the Hoover Dam, where traffic has been bumper to bumper for decades. Since the Sept. 11, 2001, attacks, the Hoover Dam has been considered a high-risk target, and large trucks have been forbidden from crossing altogether.

Trucker Bret Bartley says he has been waiting about five years for the bridge to open, and when it does, he, along with thousands of other truckers, will save at least an hour each way on trips between Arizona and Nevada.

"If I can reduce the cost to the truck for the trip, then that just benefits my company and benefits me down the road," Bartley says.

The bypass bridge was built for commerce, but it is already a tourist attraction. Like the Hoover Dam, people can park and walk across. Highway officials expect the new bridge to carry about 15,000 vehicles a day as soon as it opens, and thousands more over the next few years.