Project Overview
May 2025
The Montana Department of Transportation (MDT) and BNSF Railway Company (BNSF), formerly Montana Rail Link, have agreed upon a pier removal and bridge mitigation solution for the Blackfoot River near Bonner. BNSF is proceeding with bridge mitigation work beginning this summer, and MDT is planning pier removal under their structures once BNSF mitigation work is complete.
MDT and BNSF’s agreement involves stabilizing the BNSF bridge structure, which will allow MDT to remove the two piers at the Interstate 90 (I-90) structures. Stabilization will not change the footprint of the bridge in the river, maintaining safety for fish, recreationalists, and wildlife, and offering a solution for all parties.
Recreational impacts are anticipated during construction. Drivers and pedestrians will notice BNSF crews on and around the railroad bridge, completing mitigation efforts beginning this summer. River and access closures are expected to begin in August and last several weeks. Impacts anticipated in 2026 will be more significant as MDT completes in-river work to remove the piers.
MDT’s primary factors when considering solutions are safety, efficiency, and environmental sensitivity.
At the end of 2019, MDT completed the reconstruction of the I-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 include the mitigation costs for another bridge (formerly MRL, now BNSF) in the Blackfoot River that would be required if the piers were removed.
Since completing the bridge replacement and stabilization on the Bonner Bridges in 2019, MDT has continued to coordinate with the railroad and secure funding to remove the piers. During this time, MRL was also acquired by BNSF. A path forward is now in motion.
Public input and communication are essential components of all projects. Additional updates will be communicated as pier removal approaches.
If you have questions or feedback, please email Becca MacLean at
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UPN 8164000