Project Overview
Updated May 13, 2026
The Montana Department of Transportation (MDT) has partnered with M.A. DeAtley Construction, Inc., to reconstruct sections of U.S. Highway 191 (US 191) in Fergus and Phillips counties near the James Kipp Recreation Area and the Fred Robinson Bridge over the Missouri River. The US 191 – Mobridge Slide Repairs project will help stabilize a section of roadway that was damaged from landslides in the area.
Landslide sites occur in three different locations along US 191, and repairs at these sites will be completed in two phases.
Phase 1
The first phase includes work at Site A (see map below), which is the largest landslide area and impacts US 191 between mile markers 84 and 85. This slide has been an issue since the late 1950s but has worsened over the last decade.
Phase 1 construction began in spring 2025 and is anticipated to continue through June 2026, depending on weather and other unforeseen factors.
Phase 1 improvements at Site A are detailed below.
During the 2025 construction season, crews:
- Reconstructed embankments to mitigate landslide movements, which involved adding a toe berm and shear key at the base of the landslide (see visual below)
- Enhanced drainage on Knox Ridge Road
- Began working on improvements to drainage features
- Started construction of a new roadway surface
Remaining Phase 1 improvements planned for 2026 include:
- Completing the drainage improvements
- Improving the grading of the roadway
- Completing construction of the new roadway surface
- Upgrading safety features such as new guardrail, signage, and pavement markings
Up-to-date road conditions can be found on MDT 511.
Phase 2
The second phase of construction will involve work on two additional landslide locations between mile markers 85 and 86 (Site B), north of the Mobridge Slide (Site A), and near mile marker 89 (Site C), just north of the Missouri River.
Phase 2 construction is anticipated to begin in 2027, depending on completion of design and availability of funding.
Phase 2 improvements are detailed below.
At Site A, crews will:
- Complete final site construction (jack-and-bore culvert and final pavement installation)
At Sites A and B, crews will:
- Reconstruct the soil structures supporting the roadway to prevent further deterioration of the roadway
- Improve drainage features to reduce infiltration of surface water on the roadway
At Site C, crews will:
- Widen the roadway
- Repair the roadway to address bumps and settlements caused by landslide (heaving)
Project Map
Project Camera
UPN 9919000