Project Overview

What is the Missouri River Fort Benton Bridge project?

The Montana Department of Transportation’s (MDT) Fort Benton Bridge project evaluated the existing bridge over the Missouri River. The analysis of alternatives to either repair or replace the bridge focused on solutions to increase its service life, best use of public funds, and impacts to the public during construction.

The project analyzed four alternatives:

• Rehabilitation 1 — Deck mill and overlay along with other miscellaneous structure repairs.
• Rehabilitation 2 — Replace the deck along with other miscellaneous structure repairs.
• Replacement 1 — Replace the bridge at the current location and provide a temporary detour structure to maintain traffic during construction.
• Replacement 2 — Replace the bridge utilizing phased construction to maintain traffic without a temporary detour structure. This requires shifting the alignment upstream.

Through the Alternatives Analysis, MDT determined that the most beneficial alternative is a bridge replacement. Currently, Replacement 1 is moving forward.

• Preliminary bridge and roadway design to finalize the alignment and grade.
• Stakeholder meetings will be ongoing throughout design. Open house style public meetings will occur at key project milestones.
• Final design.
• Construction.

What is wrong with the current bridge?

The bridge was constructed in 1962 and is still safe to use, but the bridge deck (the part you drive on) is in poor condition and needs repair. The bridge has other deficiencies, such as a narrow roadway and inadequate shoulder width.

Why is the bridge so important?

Fort Benton is the crossroads for business in Chouteau County. Infrastructure that is in good condition is vital to the local and regional economies, including businesses such as wheat growers, grain processors, trucking, and tourism.

Project Schedule

This project is currently in the design phase with a target to complete design by spring 2026, budget and other factors permitting. Construction is tentatively planned to begin in 2027.

Deliverable	Timeframe
Review existing conditions and determine bridge repair needs.	Complete
Meetings with stakeholders.	Complete
Identify bridge rehabilitation and replacement options.	Complete
Prepare Draft Bridge Alternatives Report for MDT.	Complete
Stakeholder meeting.	Complete
Develop a preliminary design of the preferred alternatives.	Complete
Host Public Open House.	Complete
Finalize Project Design.	In Progress
Begin Construction on Project.	Tentatively Planned for 2027

UPN 9319001