Montana Department of Transportation officials say the historic Old Steel Bridge in Kalispell - the first steel bridge built across the upper Flathead River - should be closed because of serious safety concerns.

Ben Williamson, the agency's Missoula District bridge coordinator, inspected the 111-year-old structure earlier this year. In a letter dated Monday, he informed the Flathead County commissioners of his findings.

"The deck surface showed numerous locations of serious rot," he wrote. "Conditions ranged from split longitudinal timber planks, loose planks and minor potholes in the asphalt overlay, to rotting longitudinal wear planks, rotted transverse deck planks and complete section loss."

Williamson said the bridge deck consists of transverse timber planks topped by longitudinal wear planks and a thin asphalt overlay.

"The advanced number of crushed timber wear planks, the new rot holes, the extensive number of asphalt pieces released from the rot holes … indicate that the transverse deck planks are suffering serious problems," he said. "It is my opinion that this bridge [should] be closed until extensive repairs can be performed."

During a meeting with the county commissioners on Thursday, Missoula District Administrator Dwane Kailey said the department plans to replace the Old Steel Bridge with a new structure.

However, that project is probably at least four years from completion, he said.

"Right now, the design [for the new bridge] is slated to be finished in December 2006," Kailey said. "We're looking at how we can expedite that," but even if the design is completed sooner, the construction will still take another two years.

Flathead County Road Superintendent Charlie Johnson, who was at Thursday's meeting, reluctantly agreed with the agency's assessment.

"I'm really concerned about this bridge," he said. "We can't fix the holes. The deck is so rotten, the bolts just pull loose. It's become a major hazard."

Even if the planks could be replaced, it's questionable whether the county could pay for the repairs. Johnson said local timber supply firms are hesitant to provide quotes for the lumber.

"Nobody thinks we're serious," he said. "They know it's going to run more than $100,000, and they know we don't have the money. It's going to be almost impossible financially to replace that deck."

Commissioner Gary Hall said he didn't think it's a viable option to close the Old Steel Bridge until the new bridge is finished.

"We need to get creative" about repairing the structure, he said.

There was some discussion about replacing the wood planking with metal plates, but Johnson was concerned that the added weight might cause it to collapse.

Kailey said the Department of Transportation is willing to work with the county to try and find a solution, but ultimately it's a matter of public safety.

"We have some serious concerns about that bridge," he said.

The commissioners will continue their discussion of this issue on June 6, when they meet with the state's bridge bureau chief and head of bridge maintenance.

Reporter Bill Spence may be reached at 758-4459 or by e-mail at bspence@dailyinterlake.com