MISSOULA — A bridge to a popular recreation site on the Blackfoot River could be reopened by spring if repairs go as planned.
Missoula County recently approved a $21,000 contract with DJA for engineering oversight, leading to repairs of the Sunset Hill bridge near Greenough.
The Montana Department of Transportation ordered the bridge closed last September over structural concerns.
“They had concerns about some deformation on a structural member of the truss,” said county engineer Eric Dickson. “It's important to local users and a lot of river access folks in the summer. We've been working on how to get that back open.”
MDT has inspected the bridge at several points over the last several years. In 2023, the deformation measured roughly 4.5 inches. By 2025, it had grown to 4 5/8 inches.
"This is not a new issue, but they've seen some movement and that was enough of a concern for them,” Dickson said. “It wasn't safe for vehicular traffic anymore.”
DJA had completed a preliminary engineering report on the bridge several years ago when the county planned to seek federal grants to repair the bridge.
But looking for an easier fix, the county settled on a flame straightening process, or using heat to correct the deformation. The county used a similar technique in 2003 on the McClay Bridge.
“They're ready to get to work,” Dickson said. “They can do the work this spring when it's still relatively cool. That heat straightening process is more effective than trying to do it when it's 95 degrees in the summer. It seems to be a relatively straightforward process.”
The actual repair work will cost around $40,000, but the bridge should be open by summer, Dickson said.
“The state will have their district inspectors check the work when we're done,” he said. “That will be the process for opening – to verify the repair has been completed.”
