Montana Department of Transportation

Public Involvement

S-472 Blue Slide Road Repair
Sanders County

Construction Update

  • One lane of traffic will be open at all times over the Memorial Day Weekend beginning Thurs., May 24 through Tues., May 29. Traffic will be controlled with stop lights.
  • Starting Wed., May 30 the road will be closed during the day between 7 a.m. – 7 p.m. for construction, but will have one lane open after 7 p.m.
  • MDT anticipates having two lanes of traffic open by mid-June.

Project Overview

Blue Slide Road Project image

The Montana Department of Transportation is reconstructing a section of Blue Slide Road nine miles west of Thompson Falls that was severely damaged in April 2018.

Heavy spring snowmelt combined with heavy rain caused Cougar Creek to overflow and wash out the gravel beneath the pavement on Blue Slide Road.

Reconstruction of the roadway is occurring in two phases.

PHASE 1 | Short-term fix to stabilize and open the roadway to traffic.
May — June 2018

  • Work will be conducted during the day between 7 a.m. and 7 p.m.
  • Traffic will be controlled with stop lights and/or flaggers.
  • Some full closures and detours may be necessary.
  • MDT will notify the community in advance of closures and detours.
  • Once open, motorists will drive on gravel surface and speed limit will be reduced.

PHASE 2 | Long-term fix to prevent future damage.
July — Fall 2018

  • Complete full evaluation and identify issues that caused the damage.
  • Conduct environmental evaluation and hydraulic analysis.
  • Finish rock fall mitigation evaluation.
  • Host public open house to share Phase 2 construction plans.
  • Construction complete in Fall 2018.

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TEXT: BLUESLIDE TO 22828 | CALL: 406-465-3350 | EMAIL: