Drivers traveling along Interstate 90 west of Alberton will want to keep an eye out for some construction activity as plans move forward to replace the westbound bridge over the Clark Fork River near the Cyr Interchange. 

The Montana Department of Transportation, working with Frontier West, will begin the first phase of the project this week. Crews will start building traffic crossovers that will eventually allow both eastbound and westbound motorists to share the eastbound lanes of I-90 while the aging westbound bridge is replaced.

For now, drivers can expect occasional single-lane closures as crews prepare the roadway for the larger construction project. The main bridge work is scheduled to get underway in spring 2027, weather and other unforeseen circumstances permitting.

 Once construction begins, traffic in both directions will be routed onto the eastbound side of the interstate, with reduced speed limits in place. The good news for folks traveling to and from the Cyr area is that the on- and off-ramps at Exit 70 will remain open throughout the project. 

There may be some temporary closures of the Clark Fork River while crews remove the existing bridge, so river users should also be aware that construction could occasionally affect access to the water next year. 

The project is located approximately five miles west of Alberton and is an important piece of maintaining the interstate infrastructure that keeps traffic moving through Mineral County and western Montana. 

Anyone with questions or comments about the project can contact MDT Public Involvement at 406-444-6274 or email [email protected].