Its historical duty done, old Minnesota span needs new home

For 146 years the Kern Bridge has spanned the Le Sueur River from rural Mankato to South Bend Township.

Built originally to handle horse-and-buggy traffic, the nearly 190-foot-long structure is on the National Register of Historic Places. But it has suffered so much erosion and damage over the years that the Minnesota Department of Transportation (MnDOT) now plans to take it down later this year.

But what do you do with a worn and weathered bridge that has historical significance but is in danger of collapse if not taken down?

That's the question facing MnDOT, Blue Earth County, and Mankato and South Bend townships.

Because of the bridge's unique characteristics — it is one of only a few still standing made with wrought iron rather than steel — MnDOT and the other government entities wanted to preserve it rather than see it destroyed.

"For the bridge's [historical meaning] we just want to do whatever we could within reason to see how the bridge could be saved," said Kristen Zschomler, the cultural resource unit supervisor at MnDOT.

Doing so has been a yearslong battle that began with finding the roughly $1 million-plus needed to dismantle, store, refurbish and relocate the structure. Thanks to local and federal sources, most of the money came through last winter.

"It's hard to find the perfect setting for the bridge because of its historical significance," said Lisa Bigham state-aid engineer for MnDOT's Mankato office. "We want to find it a new home, but without taking away its unique features."

The bridge, defined by its bowstring or arch shape, is the longest bowstring arch-through-truss design bridge still standing in the United States and was built by the Ohio-based Wrought Iron Bridge Co. in 1873. It was named after a farmer — John Kern — who lived nearby.

Each piece of the bridge is connected by pins, which allows it to be disassembled and put back together.

"You have these various pins that are holding together all these members in place, and the idea is if you start pulling all of the pins out you can collapse the bridge out and move it to a different spot," said Denis Gardner, who authored the book "Wood, Concrete, Stone and Steel: Minnesota's Historic Bridges."

Gardner said it "wasn't that uncommon" in the late 1800s for bridges to be pin-connected so that they could be disassembled and reassembled if needed.

Even though it is no longer in use and has been barricaded to the public since 1991, many residents still visit the structure, which spans the Le Sueur River off a now abandoned township road in rural Blue Earth County.

To some of the older residents, it brings a sense of nostalgia, Bigham said.

It's been a spot where people would go for "all kinds of things, like beer parties, lots of photos, senior pictures and everything," Bigham said. "It has a history here within the community."

While some who are trying to find a new home for the bridge hope to place it within the county, any spot might do.

"We've had people come forward expressing interest [in] the bridge, and it's just to see who's willing as an agency to champion the historical work," said Blue Earth County Engineer and Public Works Director Ryan Thilges.