Bridge over Colorado River at Hoover Dam

The bridge over the Colorado River, immediately below Hoover Dam is making great strides. I've received multiple sets of spectacular photos but without anyone sure where they came from, so I can't attribute them.

The bridge will link Arizona and Nevada via Highway 93 and avoid the painfully slow drive across the dam to get across the river. Developers are expecting tens of thousands of new residents in northwest Arizona once the bridge is complete. That is going to increase demand for water and energy in the region.

According to the posts being circulated:

Creeping closer inch by inch 900ft above the Colorado River the two sides of a $250 million bridge at the Hoover Dam is slowly taking shape.

The bridge will carry a new section of US Route 93 past the bottleneck of the old road which can be seen twisting and winding around and across the dam itself.

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 24ft 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 1,000ft across. At the moment, the structure looks like a traditional suspension bridge. But once the arches are complete, the suspending cables on each side will be removed.

Extra vertical columns will then be installed on the arches to carry the road. The bridge has become known as the Hoover Dam bypass, although it is officially called the Mike O'Callaghan-Pat Tillman Memorial bridge, after a former governor of Nevada and an American Football player from Arizona who joined the US Army and was killed in Afghanistan.

Work on the bridge started in 2005 and should finish next year. An estimated 17,000 cars and trucks will cross it every day.