MANKATO — After 147 years years spanning the Le Sueur River and six years residing in a disassembled state in shipping containers, the Kern Bridge is about to reemerge in Mankato’s Land of Memories Park.
The historic Kern Bridge should be fully restored and in place this fall over the Blue Earth River, providing a pedestrian connection from Sibley Park and the Minnesota River Trail to Land of Memories.
But first the puzzle needs to be put back together — something set to begin this month.
Constructed in 1873 over the Le Sueur River southwest of Mankato, the one-of-a-kind bowstring arch bridge was removed from its original location in 2020 — years after the township road it served had been closed to traffic.
The 189-foot wrought iron bridge isn’t quite long enough to span the entire Blue Earth River, so bridge extensions and piers have been constructed on each bank.
All of the concrete structures are now complete, and the off-site rehabilitation of the hundreds of pieces of the old bridge is wrapping up, said Mankato City Engineer Cory Bienfang.
Bienfang expects the shipping containers containing the refreshed 153-year-old iron pieces to arrive in Mankato as soon as this week, with four to six weeks required to methodically reassemble the bars, beams and rivets.
As the bridge is being reassembled and eventually lowered by cranes onto its new piers, Mankato City Council member Mike Laven suggested there would be enough public interest to warrant a livestream. Staff aren’t planning anything quite that continuous, but the process will be recorded on video, including with drone shots, and posted on the city website.
“We definitely need to capture that,” Bienfang said.
Once the bridge is set in place, ornamental railings will be added and the trails will be finished. People should be walking and biking across the span this year.
“It’s a fall completion date,” he said.
The Kern Bridge will be connected to the trail system in Sibley Park, which includes the Minnesota River Trail. And a new trail to be constructed in Land of Memories will connect the west side of the Kern Bridge through the park, past a new playground and to the existing Minneopa Trail that passes just outside the park entrance and runs nearly all the way to the state park west of Mankato.
Believed to be the longest vintage bowstring arch bridge remaining in America and the last of any length in Minnesota, the Kern Bridge was on the verge of collapsing into the Le Sueur River in South Bend Township a decade ago. The problem was deteriorating stone piers, not the iron span itself, and state and county officials managed to secure federal funds to rescue it.
After it was removed from the crumbling piers and dismantled, the Minnesota Department of Transportation held an open competition for local governments interested in taking ownership for use by pedestrians and/or bikers. Mankato was chosen as the winner early in 2021, with design work and navigation of the complex state and federal approval process following.
Redstone Construction of Mora — with a bid of $8.38 million — won the contract to build the supporting structures, construct a section of elevated trail on the Land of Memories side, reassemble the bridge and set it in place. Even Redstone’s low bid was 15% above the engineer’s estimate for the work, and the project’s total cost — including a 5% contingency fund — rises to $10.5 million when design fees and the expense of the associated connecting trail in Land of Memories Park are added.
Redstone remains on schedule and on budget, Bienfang said.
Financing for the project includes $6.7 million in federal funds, $1.4 million in city park funds, $1.2 million in local sales tax revenue and $1.2 million in state assistance.