Last Saturday's rock slide that closed US20/WY789 for 4 hours in Wind River Canyon is forcing early mobilization for prime contractor Oftedal Construction, Inc., of Casper and its rock slide mitigation subcontractor for the second year of work on a slide stabilization project.
The $8.78 million slide stabilization project includes slide repair, grading, slide stabilization rock (SSR), manual rock scaling, rock fall mitigation and other work on US20/WY789 beginning at milepost 115.9 through 123.12 inside the canyon between Shoshoni and Thermopolis.
Subcontractor Midwest Rockfall, Inc., of Henderson, Colo., is scheduled to be on site beginning Tuesday, April 26.
Some of Midwest Rockfall's rockfall mitigation work still remains from the original contract -- installing a rock attenuator system, installation of rock bolts, repair of existing rock fence and installation of new rock mesh -- but now the subcontractor's work will also include emergency tasks at the rock slide which closed the highway Saturday evening.
"Oftedal is moving in equipment to move the current talus rock that fell on the highway Saturday so other rocks on the slope have a place to fall that's not on the highway," said Wyoming Department of Transportation project engineer Jordan Erz of Worland. "Midwest workers will then perform rock scaling work on that area to hopefully remove all the loose rock. There are also a few big rocks above the road that thankfully did not fall Saturday night. These big rocks must be moved to the roadway as soon as possible to make that area as safe as possible."
Erz said the big rocks remaining above the roadway from Saturday's rock slide are sitting in fragile areas and could move downhill on their own, and the expedited work schedule is "a proactive decision to enhance human safety and avoid further damage to the roadway."
In other Wind River Canyon project work, Oftedal will be installing 3 pipes to move runoff water on the project.
At the same time, southeast of Wind River Canyon, asphalt paving is scheduled to begin this week on 8.36 miles of US20/WY789 between the town limits of Shoshoni and Birdseye Road between Shoshoni and Wind River Canyon.
With the projects so close to each other, motorists should expect combined stop delays of up to 35 minutes through the $4.74 million paving project and slide cleanup effort.
When paving is complete north of Shoshoni, Mountain Construction will be paving the Upper Wind River Campground in separate work for Boysen State Park. That work on the campground roadways could also add to the length of the traffic delays between Shoshoni and Thermopolis.
Project questions may be directed to WYDOT Resident Engineer Kaia Tharp, P.E., at (307) 864-3200, or by email at firstname.lastname@example.org