Project Overview

Bonner Bridges Project image

The Montana Department of Transportation (MDT) and Montana Rail Link (MRL) have agreed upon a pier removal and bridge mitigation alternative in the Blackfoot River. At this time, MDT and MRL are working together to implement the preferred design option as funding and timeline are determined.

At the end of 2019, the Montana Department of Transportation (MDT) completed the reconstruction of the Interstate 90 bridges crossing the Blackfoot River. However, the piers at the Bonner Bridges site were not removed due to additional costs that would be incurred. These costs include the maintenance costs for another bridge (MRL) in the Blackfoot River that would be required if the piers were removed.

Since completing the Bonner Bridges project in 2019, MDT has continued to seek opportunities and funding to remove the piers.

The Montana Department of Transportation was in conversation with numerous stakeholders in order to determine the best possible solution for pier removal moving forward. MDT's primary factors when considering solutions were safety, efficiency, and environmental sensitivity.

Recently, MDT has partnered with consultants to review various alternatives for the removal of the two piers from the Blackfoot River. These options take into consideration the Montana Rail Link bridge located just south of the piers and the protection of the surrounding environment.

MDT and MRL have now come to an agreement on an alternative that requires piles socketed into the bedrock next to the piers to stabilize the structure. The alternative would lower the footprint in the river, increase safety for fish, recreationalists, and wildlife and offer a solution for all parties. The total price tag for mitigation of the MRL bridge and pier removal is approximately $9 million in total.

The Montana Department of Transportation and Montana Rail Link are hard at work to acquire the necessary funding to complete this project and determine when it can take place. We understand that the removal of the piers in the Blackfoot River is a priority and are doing everything possible to move the project along swiftly.

Please email Katie with questions. Prefer to be updated via text? Text Bonnerbridges to 41411.