The one-lane, wood-decked truss bridge a couple of miles outside the town of Amboy hasn't held car traffic for more than five years. The county engineer shut it down in the spring of 2009, deeming its deterioration too dangerous to hold heavy vehicles.

But now, after preservationists fought for years to save it, the bridge dubbed the Dodd Ford Bridge is poised to carry cars and trucks over the Blue Earth River again. MnDOT agreed last month to spend more than $1.1 million to reinforce the aging bridge on County Road 147, with Blue Earth County contributing about $130,000.

The commitments signal an end to a long controversy.

County officials contended the bridge needed to be removed and replaced with one that could carry heavy farm equipment.

Preservationists argued that its scenic location in a tree-lined, winding part of the river had made it a historical gathering spot for families to picnic, fish and swim.

"In the early days of motoring, this was like a destination," said Erin Hanafin Berg, field services and programs manager for the Preservation Alliance of Minnesota. "This was the place that people would take their Sunday drives."

The 148-foot-long span, with a camelback truss, was built with a fracture-critical design like the old Interstate 35W bridge in Minneapolis; if one key piece failed the whole thing could collapse.

For decades, it was restricted to vehicles weighing 3 tons or less and carried only about 35 cars a day. Then, five years ago, it was closed to all motorized vehicles.

"It's in farm country and we know that even a loaded pickup truck pulling a trailer of seed corn would be far in excess" of what was safe, Blue Earth County Engineer Al Forsberg said.

Preservationists argued that it wasn't necessary to replace the bridge because other crossings a few miles on either side were accommodating farm equipment already. They managed to get it listed on the National Register of Historic Places.

Proposals to build a new bridge next to it or move the old bridge somewhere else fell through. At one point, county officials even put the bridge up for sale. Officials and groups couldn't find funding to rehab the bridge for recreational use only.

Finally, a plan emerged to reinforce the Dodd Ford bridge from the bottom, giving it the capacity to hold modern loads including trucks more than 80,000 pounds. The bridge will look much the same from the top, though it will have a concrete deck instead of wood.

"I think our community got behind something they saw as a local treasure," said Amboy restaurant owner Lisa Lindberg, who helped lead preservation efforts. "It's been a true challenge."

Forsberg anticipates the reinforced bridge will carry 100 to 200 cars a day. The county will take bids for the work through early August.