It's been more than 90 years since crews completed the original Navajo Bridge, an arching, architecturally significant span that looms dramatically across Marble Canyon and provides a rare vehicle crossing of the Colorado River in a remote, rugged part of the Southwest.

On Jan. 12, 1929, the first traffic rumbled across what was then the world’s highest steel-arch bridge. While a grand opening celebration would wait until June, that day marked a pivotal moment in Arizona’s economic and transportation development. This milestone of engineering design carried travelers 467 feet above the river to connect the Arizona Strip with the rest of the state.

“As the only crossing of the Colorado River for some 600 miles, the Navajo Bridge has had a profound impact on the commerce and transportation of a rugged, remote and isolated part of Arizona,” designer Clayton Fraser is quoted as saying in the National Park Service’s “Historic American Engineering Record.”

“An extraordinarily dramatic span high over the Grand Canyon, the Navajo Bridge is Arizona’s most aesthetically and functionally successful example of civil engineering,” Fraser said.  

For half a century before that, travelers used Lees Ferry at the bottom of Marble Canyon several miles upstream from where the bridge was built. According to the Engineering Record, boat crossings began in 1873, and the ferry was the primary passage until the opening of the Navajo Bridge, which was first called the Grand Canyon Bridge.

Throughout construction of the 834-foot-long, 18-foot-wide span, the biggest challenge was the river itself, which, according to the Engineering Record, “cut through the road like a giant slash in the desert fabric.”   

Laborers toiled long hours from dizzying heights above the river. Crews drilled and graded rocky bluffs. Supplies were carried on precarious footing.

It was with little fanfare that the Arizona Highway Department, the former name of the Arizona Department of Transportation, opened the bridge on Jan. 12, 1929. A chill wind blew on the few laborers and engineers who gathered in acknowledgement.

A gala ribbon cutting was scheduled during balmier weather on June 14-15.

As quoted in Engineering Record, The Arizona Republican, as The Arizona Republic was named at that time, described the scene as follows:

“Under a typical Arizona cloudless sky, the heat tempered by a gentle, southern breeze, the Grand Canyon Bridge across the chasm of the mighty Colorado river was formally dedicated by four governors of neighboring states this afternoon in the presence of a crowd of more than 5,000 persons, representatives of least 20 states.

“As movie and other cameras clicked and with three other chief executives of as many states standing by, (then) Governor John C. Phillips clipped the purple and yellow ribbons which represented the breaking of an age-old barrier between the lands to the north and south of Colorado River.”

The structure still exists today, though it has been a pedestrian bridge since 1995, when a new vehicle bridge was built 150 feet downstream to handle heavier, wider vehicles of contemporary times. 

The 1995 bridge is, as progress would dictate, longer, higher and with an increased steel arch length than the original, among other signicant updates. But the biggest difference, as you can guess, is dollars and cents. It cost $390,000 to build the historic bridge, while the modern span cost $14.7 million.

We've done blog posts about the bridge before, including this before-and-after view and this explanation of how ginger ale played a part in the bridge's hstory. If you are interested, you can also find a more detailed history of this important structure from the primary resource used in this report, National Park Service’s “Historic American Engineering Record.” Also of interest is this more recent report from the National Park Service.

Driving along US 60 at Pinto Creek, motorists see heavy equipment carving a road out of the rocky terrain at what might seem like a slow pace.

But when the highway is closed to the public, progress comes in bursts.

Just take a look at how quickly explosives dislodge rock in this video captured by ADOT’s video team. The blasting is the most dramatic part of a two-year project to replace the Pinto Creek Bridge, which requires carving an access road into the canyon so crews construct bridge piers.

The blasting has been underway for several weeks, when crews close the highway twice a week between Superior and Miami to keep the public at a safe distance. Blasting will continue Tuesdays and Thursdays, from 9 a.m. to 1 p.m., into December.

The explosives are used on rock that’s too hard to be removed by earthmoving equipment. But construction also occurs on weekdays, when crews remove softer rock, continue building the access road and prepare for the next blasting operation.

Drivers in the area should expect lane restrictions and allow for extra travel time. Keep up to date on scheduled restrictions or closures at azdot.gov/PintoCreekBridge.

While the electric slide enjoyed the height of its popularity in the 1990s, ADOT and its contractor for the Bellemont bridge project, Fisher Industries, are introducing the bridge slide as an innovative method for accelerated bridge construction.

The bridge slide method, which we detailed recently in a news release, involves pre-casting new bridges right next to the existing bridges. The old bridges are then demolished and new bridges are lifted and “slid” into place using hydraulic jacks. This process took less four-and-a-half days to accomplish on the Bellemont project once the new bridges were built.

This method was proposed by Fisher Industries through a process called value engineering where the plans of a project are analyzed looking for ways to improve quality and value while reducing time needed to complete the work.

This bridge-sliding method takes months off of construction time compared to the traditional way of building new bridges while maintaining traffic through the area. The residents and those who travel through Bellemont are spared months of lane closures and restrictions thanks to this innovative method.

Check out the time-lapse video taken by ADOT’s video team to see how the bridge-slide method works.

Let’s face it: Nobody looks forward to construction delays.

But with restrictions and some temporary closures set for the Pinto Creek Bridge replacement project on US 60 between Superior and Globe, we’re giving drivers something they can look forward to: a predicable schedule.

With a little planning now, you can avoid some frustration and save time.

Here’s what to plan for:

• Daily lane restrictions begin Thursday (Oct. 31) and continue for several weeks Mondays through Thursdays between 6 a.m. and 4 p.m., and Fridays from 6 a.m. to noon.
• Full closures are tentatively set to begin Thursday, Nov. 7. The closures will continue for several weeks on Tuesdays and Thursdays from 9 a.m. to 1 p.m. Drivers will detour on state routes 77 and 177 through Winkelman, adding at least 45 minutes of travel time between Globe and Superior.

While much of the construction will occur in Pinto Creek Canyon, we need the restrictions as crews continue building an access road into the canyon and removing rock to shift part of the highway about 30 feet. Crews will need to blast away some rock, which requires full highway closures for safety.

As we shared in an earlier news release, there is some encouraging news already: In the first few weeks, crews found the rock is softer than expected and can be removed with heavy equipment rather than by blasting. If that continues, we can reduce the number of full closures.

Additional restrictions and closures will come later in the project. They’ll include overnight closures to install bridge girders and pour the new structure’s concrete deck. Near the end of the project, we’ll need to close the road for about five days to shift the highway so it lines up with the new bridge.

Drivers will continue using the existing bridge until the new 695-foot-long structure is completed in about two years. When we're done, the new structure replacing a 70-year-old bridge will give motorists reliable transportation for decades to come.

Motorists can keep up to date on restrictions by subscribing for email updates at azdot.gov/PintoCreekBridge.

If you travel east of Flagstaff along Interstate 40, you may have noticed crews hard at work building a new bridge at the Meteor City Road interchange. You might be thinking that this is going to take the better part of a year to get done.

Actually, by using new and innovative techniques ADOT intends to have this entire project, which started in mid-July and would ordinarily take six months or more, wrapped up this fall.

Crews are creating bridge abutments by putting in alternating layers of granular fill reinforced with synthetic material. This method is known as a geosynthetic reinforced soil-integrated bridge system, and it’s ADOT’s first use of this technique.

But wait, there’s more. A second first-time innovation being employed to build this bridge involves a new way to lay the bridge deck.

The deck will be constructed using a polyester polymer concrete that can be placed and cured in a matter of days rather than weeks. This type of deck provides similar performance with lower maintenance costs compared to a traditional concrete bridge deck.

This is not only a first for ADOT but for the state.

The Arizona Management System championed by Governor Ducey challenges ADOT and other state agencies to continuously improve their value to customers – in this case to the drivers and others who will benefit from a faster project that will yield lower maintenance costs through the years. This innovative approach is allowing us to do just that.