The Wyoming Department of Transportation and its contractor GSI will work together to begin emergency repairs to a landslide west of Sheridan. Ron Richter of Sheridan Media has the details.

The Wyoming Department of Transportation Commission has approved $341,137 in emergency funding to the Fourth District to address a landslide that has been ongoing for several years and could potentially result in a road closure. This mitigation measure was necessary to ensure mobility on Interstate 90 until the STIP construction project planned for that section can be completed. A landslide is a common phenomenon in Sheridan County and occurs when soils, usually clay, become overly saturated and lose their “stickiness” and give in to gravity. This particular landslide is located in the eastbound lane of I-90 near mile marker 6.9 west of Sheridan.

This landslide was first noticed by Sheridan maintenance personnel in May 2017 and reported to WYDOT geologists, who have been monitoring it since then. Due to the aggressive new movement of this landslide, the lack of road shoulder, and compromised temporary guardrail installation, the district’s maintenance personnel determined the landslide needed to be mitigated before the right lane would be impacted. WYDOT’s contractor, GSI, is scheduled to begin work on the landslide the week of August 19. The work will require WYDOT to temporarily close the right lane to motorists. Traffic control will include closing the eastbound right lane near mile marker 6.9, and the speed limit will be reduced to 45 mph. Prior to the emergency funding request, construction plans were finalized to mill, grade, and overlay I-90 from Montana State Lane from mile marker 0 to 8. This project is scheduled to be tendered and awarded in October of this year, with an expected start date in spring 2025.

The scope of the project also includes relocating both eastbound lanes toward the median to avoid this and other potentially dangerous landslides between mile markers 3.88 and 8. The project also includes major repairs to two bridge structures and replacing four bridge structures with box girder culverts. This project has been part of the State Transportation Improvement Program (STIP) since 2018 and is expected to cost $36 million.