One of Minnesota's oldest bridges will get new life in Mankato recreation area

A rare, old bridge will get new life as the centerpiece of a popular Mankato recreation area, spanning the Blue Earth River and joining together several major parks and trails.

The wrought-iron Kern Bridge had been a local landmark since it was erected in 1873 to span the Le Sueur River in Blue Earth County southwest of Mankato. Closed to vehicle traffic in 1991, the bridge was disassembled last year and stored in four large shipping containers. The Minnesota Department of Transportation (MnDOT) then took proposals from cities and counties for repurposing the bridge.

Mankato won out over three other finalists, including the city of Fergus Falls and Sherburn and Watonwan counties. In its new setting, the bridge will link Sibley and Land of Memories parks, as well as providing a river crossing for the planned Minnesota River State Trail.

The Kern Bridge is an unusual design known as a bowstring arch. It's one of the oldest bridges of any type in Minnesota and is the only bowstring arch bridge remaining in the state. At 189 feet in length, it's also the longest bowstring arch bridge in the United States.

Wrought-iron bridges from this era also are rare, as bridge builders after the Civil War were increasingly switching to steel.

"It's incredibly rare. It's a testament to how people used to build things," said Katie Haun Schuring, a historian with MnDOT's Cultural Resources Unit. "The fact that it's going to be resurrected is really heartwarming.

"This bridge particularly captured my interest," she said. "It's something that you just don't find, and when it's gone, it's gone. It's super special to the state — and really, to the nation."

In its time, the bridge has carried horses, buggies, cars and trucks. In its new location, though, it will handle only bicycle and pedestrian traffic. It's in excellent shape, needing only some cleaning, painting and minor refurbishing, said Lisa Bigham, a MnDOT project administrator. The crumbling stone piers supporting the bridge were more of a worry to engineers than the bridge structure itself.

The bridge was built by the Ohio-based Wrought Iron Bridge Co. and took its name from John Kern, whose farm was nearby. It was built with pins holding the pieces together, rather than rivets, expressly to make it easier to move the bridge to a different location if necessary. The whole project carries an estimated cost of about $1.5 million, of which 80% will be paid with federal transportation funds and 20% from local, county or state money. The city of Mankato is in charge of the overall project.

"I couldn't be more excited for where it's going to be, where there is a nexus of a lot of things going on with trails, history, culture, art," Bigham said. "Connecting the two parks. and the whole multimodal aspect — it will serve all users and it will be designed to be ADA-accessible [Americans with Disabilities Act].

"The bridges we are building these days, we're thinking a 70- to 80-year design life. And to have this be twice that is really amazing."

John Reinan • (612) 673-7402