"Bridges tell a lot about our history," says Kitty Henderson, executive director of the Historic Bridge Foundation, a national advocacy organization in Austin dedicated to saving the bridges. "They were often built because of growth and development of a community, so the message they tell might be about how the region developed. The bridges are also important because of the engineering legacy. They tell us about advances in engineering and new ways of craftsmanship. And they are a work of art."

About half of Denton County's 17 iron bridges, which were installed in the late 1800s or 1900s, have been moved. Most were fabricated by the King Iron Bridge & Manufacturing Co. in Ohio and brought to Texas.

"It was a prestige point at that time, in the late 1800s, to have a community with an iron bridge. I was an indication how modern the city was," says Tommy Brewer, a volunteer with the Denton County Historical Commission.

But now as single-lane bridges, they are too narrow for modern roads.   

"The bridges are substandard either in structure or size capacity for the area, and they need to be replaced with larger bridges," says Bennett Howell, an engineer with the Denton County public works department. "Usually they are used as pedestrian walkways and in parks and government facilities."

Denton Independent School District acquired one of the largest bridges and moved it to the new Guyer High School campus a few years ago, where it spans an environmentally sensitive area and serves as a pedestrian link between the academic and athletic portions of the campus.

Above: Guyer High School's bridge, formerly the Rector Road Bridge. Photo courtesy Lucy Haverkamp, Create.

"We're bringing a younger generation to appreciate history and live with an artifact," Brewer says.

Glen Martin, construction coordinator for Denton ISD, recalls that a convoy of 20 vehicles accompanied the bridge, lifted onto a large trailer, the 23 miles from its original location.

Bridge expert Eric Delony of Santa Fe, New Mexico, explains that what's entailed in moving one of the structures depends on its size, but they must be adequately braced. They cannot simply be lifted from above with a crane and set on a flatbed.

"If you lift from the upper cords, it will cause a reversal of stress, and the bridge will warp and fall apart," Delony says.     

As historical landmarks, the bridges must be restored according to historical commission regulations to keep their historical significance intact. Brewer anticipates it costs between $30,000 and $50,000 to move a bridge, build the abutments and preserve one.

"Everyone who winds up with one of these bridges is so proud that they participated in historic preservation," Brewer says. "It's a very impressive site to see a big [iron] bridge in good shape and painted. It's an attractive structure."

Henderson says that Texas has done a fairly good job of preserving its bridges. In addition to Denton County, Gonzales moved the historic, 140-ft long Oak Forest Bridge to a park for pedestrian traffic, and Nacogdoches plans to move the Goodman Bridge to Pecan Park.

Above: The Oak Forest Bridge. Photo courtesy Craig Hanchey

The Texas Dept. of Transportation produced a Historic Bridge Manual in June, outlining the processes involved and providing guidance about coordination activities, funding restrictions and reuse options. http://onlinemanuals.txdot.gov/txdotmanuals/his/his.pdf.

Our past tells us so much about ourselves and the future, if we listen and pay attention. It's wonderful that people in so many communities in the state have taken the initiative to preserve the bridges that helped Texas grow at the turn of the last century.