There's still a week left to see a display on covered bridges at the Coplay Public Library.

Coplay resident Jack Norbeck has been taking pictures representing the Great Steam Era (1850-1920) in America since 1969.

Norbeck is the author of the book, "Encyclopedia of American Steam Traction Engines," which is part of the display at the library. The book was published in 1976, after seven years of research and photography, and eventually became the centerpiece of the exhibit that has traveled around the world.

Norbeck's "Great Steam Era" exhibit has visited all seven continents over the past 10 years. The tour included more than 40 countries and 200 cities, as well as trips aboard U.S. Naval ships.

While Norbeck has spent many years on the steam era, he decided to focus on covered bridges for the past two years.

In November, the exhibit will move from Coplay to the Parkland High School. After that, it will spend the rest of the year at the Allentown Public Library.

The bridges in Norbeck's display are from West Virginia, Virginia, Maryland, Delaware, New Jersey and Pennsylvania.

Three Whitehall bridges are featured – the Guth Bridge, the Wehr Bridge and the Geiger Bridge.

Also included are the Weaver's Mill Covered Bridge in Lancaster County, the Zimmerman's Covered Bridge in Schuylkill County, Kutz Mill Bridge in Berks County and the Phillipi Covered Bridge in West Virginia.

All of the bridges are featured in the National Register of Historic Places.

At one time, there were nearly 1,400 covered bridges throughout the United States. Now, there are less than 900. Pennsylvania has the most bridges at 200. Many of the bridges that are still standing are more than 150 years old.

The display also features all the major arch and truss styles predominantly used in covered bridge construction.

"Our covered bridges have so much charm and hold so much meaning of long ago," Norbeck said. "These bridges are the romantic hideaways where men and women would steal a secret kiss, and young love would begin. They are the places where soldiers would march their way to and from battle over 100 years ago. They are what our ancestors drove across with their horses and tractors to reach the grist mills without having to go all the way around the town. They are structural pieces of history, well-preserved, and still used today."

Norbeck said that while his exhibit represents quite a collection, it is still not yet complete.

Just this past week, Norbeck added an additional photo to his exhibit. While at the Pioneer Festival in New Tripoli this month, he met New Tripoli resident Bill Mantz, who owns a historical Oliver Tractor. Norbeck was offered a once-in-a-lifetime opportunity from Mantz to photograph the Geiger Bridge, located near the Trexler-Lehigh County Game Preserve, with Mantz driving his Oliver through it.

Norbeck has also been offered a chance to photograph Mantz's Oliver crawler, or bulldozer, which was used for harvesting potatoes.

Norbeck wants one last photo of the Oliver Crawler dozing its way through the Wehr Bridge in Whitehall Township to fully complete his display. He hopes to add that one in the next few weeks.

"These covered bridges are a special piece of history because a lot of our ancestors walked over these bridges," he says. "It's all about having respect for the preservation of history and our ancestors mark upon it."