Maclay Bridge/South Avenue Bridge

Follow this page for updates and let us know your questions about the Maclay Bridge.

Missoula County and the Montana Department of Transportation are collaborating to construct a new bridge over the Bitterroot River that would connect South Avenue to River Pines Road, which would replace the aging Maclay Bridge west of Missoula. You can find a complete timeline and more information on this project on MDT’s Bitterroot River Bridge project page (also referred to as the “South Avenue Bridge” project). The timeline can be found under “Links” on the right-hand side. Though Missoula County has been a partner in this project, MDT is taking the lead on construction. If you have any comments on the South Avenue Bridge project, please submit them via MDT’s comment form.

Currently, the County, MDT and Federal Highway Administration are regularly meeting to complete the necessary steps required by the National Environmental Policy Act (NEPA) and the National Historic Preservation Act (NHPA) of 1966. It’s critical that the process and requirements under each act be addressed accurately and thoroughly to reduce the risk of delays during the project development. The programmatic agreement for the Section 106 portion of the NHPA is expected to be completed in June 2025, with the NEPA document being signed by FHWA potentially in August 2025. This timeline is tentative and can change.

Once the NEPA process and the scope of work is complete, the County and MDT will continue to collaborate on the delivery of the project, but MDT will take the lead on project management and delivery. MDT has the project tentatively slated for funding beyond 2029, with the project being primarily funded through federal and state gas tax funds, also known as MDT’s Off-System Bridge Program.

If you have questions about the Maclay Bridge closure or South Avenue Bridge project, please read the FAQs on the right-hand side to ensure your questions haven’t already been answered. If they haven’t, ask them below.