Hoover Dam Bypass [via David Angsten]
Creeping closer inch by inch, 900 feet above the mighty Colorado River, the two sides of a $160 million bridge at the Hoover Dam slowly takes shape.
When complete, it will provide a new link between the states of Nevada and Arizona.
In an incredible feat of engineering, the road will be supported on the two massive concrete arches which jut out of the rock face.
The arches are made up of 53 individual sections each 24 feet long which have been cast on-site and are being lifted into place using an improvised high-wire crane strung between temporary steel pylons.
The arches will eventually measure more than 1,000 feet across.
Work on the bridge started in 2005 and should finish next year. An estimated 17,000 cars and trucks will cross it every day.