Previously unseen by the public, a collection of over 400 colour slides from the bridge's construction has been released by the International Bridge Administration

The International Bridge Administration is releasing a fascinating collection of historical photographs and SooToday was given a special sneak peak recently.

During the International Bridge's construction from 1960-62, former WWII photographer Carl Materna documented the projected from begining to end.

In the coming months, the bridge authority plans to release over 400 colour slides that Materna took during that time, said bridge general manager Peter Petainen.

Not only does the collection span a long period, it also covers seemingly every aspect of the construction from every view, including aerial shots.

To have bridge shots from that era in colour is a very rare thing, said Petainen who, along with bridge engineer Karl Hansen, went through all of the slides with SooToday recently.

“I just love this,” said Petainen, looking at one of the slides that had construction workers looking tiny on top of massive steel beams. “It puts the size of the bridge in perspective. It’s a massive bridge and a massive responsibility we don’t take lightly.”

Besides a look at the construction of the bridge, the slides also include amazing historical looks at St. Mary's Paper, construction of the I-75, the locks, the chromium plant, and other surrounding buildings at the time.

Please take the time to expand and look at a selection of 43 of those images in the gallery above.

Included in the slides is one of the ribbon cutting ceremony from April 17, 1962 when the Canadian and U.S. sides of the bridge officially connected with a weld.

Former Sault Ste. Marie, Ont. Mayor James McIntyre was there that day and you can see him talk about his experience, below, in a documentary put out by the International Bridge Administration (go to 5:20).