The Hoover Dam Bypass Project reached another major milestone in October 2004
with the award of the contract for the final connection – the Colorado River
Bridge.   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 June 2010.  When completed, this signature bridge will span
the Black Canyon (about 1,600 feet south of the Hoover Dam), connecting the
Arizona and Nevada Approach highways nearly 900-feet above the Colorado
River.

http://www.hooverdambypass.org/