Orange Street Tunnel

Project Overview

The Montana Department of Transportation’s (MDT) Orange Street Tunnel project in Missoula will include rehabilitation and preservation work on the existing structure. Built in 1939, this tunnel is on an important route through Missoula and is heavily used by businesses, tourists, and the community.

The Orange Street Tunnel will be rehabilitated to extend its service life as follows:

  • Replace the existing concrete superstructure that supports Railroad Street West and North 1st Street West.
  • Repair concrete on the tunnel and retaining walls.
  • Replace sections of existing retaining wall near tunnel entrances.
  • Minor roadway work associated with tunnel repairs.
  • Replace tunnel lighting.
  • Repair or replace existing railing along the approach walls and in the tunnel.

During construction, traffic will be reduced to a single lane through the tunnel to allow work on one side of the structure at a time. Short-term closures of the tunnel will be necessary to set new beams for the superstructure supporting Railroad Street West and North 1st Street West.

Methods for maintaining traffic flow during construction will be determined as the design is developed. Coordination with stakeholders and critical services will occur during the design phase to share information and help inform decisions.

Project Schedule

The project is currently in the design phase with 30% design completion anticipated in Spring 2023 and final design complete early 2024.

A more comprehensive schedule will be defined and shared as the project develops.

Project Location Map

project map

Stay Involved, Stay Informed

Stakeholder and public feedback is encouraged throughout all project phases to help MDT develop solutions for design and construction that best meet traffic and safety needs of the area and all who use this route.

New project information will be posted on this website as it becomes available.

Comments can be submitted electronically. To submit a comment, visit MDT’s Online Comment Form.

Please note that your comments are for the Orange Street Tunnel, UPN 9941000.

UPN 9941000