CARSON CITY -- Workers set steel rebar into place while perched on support columns high above Galena Creek on what will be part of a new bridge and freeway linking Reno to the capital.
Huge cranes move construction materials for the bridge, which will run 1,719 feet and include a 690-foot-high cathedral main arch spanning the small stream that tumbles out of the Sierra Nevada to the west.
Two separate spans, one for each direction, will cross the creek, 300 feet below.
Two hundred workers, specialists in bridge construction and big freeway projects, are at work on the nearly $400 million, 8.5-mile stretch of road, the last piece of what will be a divided highway between Carson City and Interstate 80 in Reno, 30 miles to the north.
On a tour of the project Friday, officials with the Nevada Department of Transportation pointed out the progress on the freeway extension, which is formally called Interstate 580.
The link will replace U.S. Highway 395, which sits far below to the east as the preferred route for motorists. It should be open to traffic by late 2011 or early 2012, said Rick Nelson, assistant director of operations for the agency.
The existing road, two lanes in each direction with a turn lane, is frequently the site of serious head-on collisions.
Nelson said he spends a lot of time overseeing the work on one of the most complex road and bridge projects ever undertaken by the agency.
The complexity comes from the decision made decades ago to run the freeway way up along the mountainside rather than some other alternate route.
"There are some folks who will spend easily a third of their careers working on this project," Nelson said. "I've been on it for six years now. The design people have been working on it for a lot longer than that."
The project, which is well into its second year of construction, is being done by Fisher Sand & Gravel Co. and its subcontractor for the bridge work, CC Myers Inc.
They will be on the job through most of 2011. Work started in early 2007.
The Galena Creek bridge is only one piece of the project, but it is the most impressive element. Workers have put into place a temporary steel frame, called falsework, to support the concrete and rebar that will make up the first of the two arch spans.
They are working off a platform of tens of thousands of cubic yards of dirt used to fill in the Galena Creek ravine. Far below, the creek runs protected through a reinforced concrete tunnel.
When the project is complete, the steel support structure will be removed, the fill will be taken away, and the only remaining feature will be the span with the longest center arches of their type in the United States.
The route selection has come in for some criticism in recent years because of its cost, but transportation officials said that decision was made years ago.
In part because of concerns about the cost, the Transportation Department now uses a cost-benefit analysis on freeway projects to make sure they are worth the expense.
The I-580 project and the second phase of a freeway bypass through the capital are the only two major highway projects under way in Northern Nevada. The third and final piece of the Carson project, an extension of I-580, is not yet funded.
The two projects were approved by the state Transportation Board years ago, along with several in Southern Nevada, including the widening of U.S. Highway 95 and the Hoover Dam bypass, which is also under construction.
Transportation Department spokesman Scott Magruder said the I-580 project is about 80 days behind schedule, although that time could be made up over the next three years. But the contractor will have to cover the cost of any delays, he said.
While the actual freeway construction is drawing the most attention, Magruder said myriad other elements are involved in the extension, from creating animal pathways for deer under the roadway to the environmental restoration of the Galena Creek area, to the use of decorative elements on the retaining wall panels as requested by nearby residents.
Some area residents have expressed trepidation about using the new freeway high above Pleasant Valley to the east, he said.
But the stretch of freeway will be the safest choice for motorists when it opens early in the next decade, Magruder said.
Contact Capital Bureau reporter Sean Whaley at email@example.com or 775-687-3900.