Why does the Kalsta Bridge at Glen need to be replaced?

The Kalsta Bridge at Glen was originally built in 1928 and is in need of replacement. The bridge crosses over the Big Hole River three miles north of Glen on Montana Highway 91 (MT 91) near Interstate 15 (I 15) Exit 85. Inspections showed the bridge has suffered extensive deterioration to its steel-truss structure and concrete roadbed and can no longer carry expected traffic loads. Since 2019, the bridge has been restricted to single-lane traffic, with a 3-ton weight and 15 mph speed limit to prevent further damage. The Montana Department of Transportation (MDT) has determined to replace the bridge with a new two-lane bridge to enhance safety features and improve traffic flow.

When will the bridge be replaced?

Bridge construction is tentatively scheduled for 2026 based on completion of design, right-of-way, and funding availability. This project is in the design phase which requires time for staff to properly create and review potential project plans. Some of the tasks that the project team performs during the design phase include reviewing past research from surveys of the project area; assessing the surrounding terrain (both above and below ground); presenting and adjusting plans based off public input; determining the feasibility of construction features; researching environmental impacts; and creating cost-effective detailed plans to guide construction.

What other factors are considered during the design of the Kalsta Bridge replacement?

MDT considers many factors throughout the design phase, including engineering, environmental impacts, and cost analysis of the project design. For the Kalsta bridge replacements and projects across the state, MDT prioritizes public safety, efficient traffic flow, cost-effective use of taxpayer funds, and stakeholder in the design. Initial plans for a new Kalsta Bridge call for widening the bridge to 28 feet, providing two lanes of traffic, and allowing access under the bridge for recreational use of the river. Stakeholders are encouraged to provide input on bridge design and other considerations throughout the process.

How can you provide comments or find more information on this project?

The public and local stakeholders will be kept informed during the design and construction phases of the project. As with all road and bridge construction projects, MDT is committed to and encourages public involvement. Updates will be posted and on the project's webpage at www.mdt.mt.gov/pubinvolve/kalstabridge/.