When I was in Las Vagas I managed to get away from and drive myself up to the Hoover Damn. I was aiming to get to the Grand Canyon but getting up late and missing my proposed departure time due to the night before meant I could only reach the Hoover Damn. Still, no harm done and I got to visit an impressive feat of engineering!
Below is some quick information on the Hoover Damn I found:
Construction of the Colorado River Bridge is advancing on the 1,060 foot twin-rib concrete arch. The Colorado River Bridge is the central portion of the Hoover Dam Bypass Project. Construction on the nearly 2,000 foot long bridge began in late January 2005 and the completion of the entire Hoover Dam Bypass Project is expected in Late 2010. When completed, this signature bridge will span the Black Canyon (about 1,500 feet south of the Hoover Dam), connecting the Arizona and Nevada Approach highways nearly 900-feet above the Colorado River.
Canon 400D, EFS 17 - 85mm f4 - 5.6, 72mm, f11, 1/80, ISO 200