Rock cleanup, slope repairs begin in Canyon

Two contractors began cleaning up May rockfall inside Wind River Canyon on Monday, including stability and rockfall emergency repairs of existing canyon walls about 10 miles south of Thermopolis in the area of Big Windy Curve.

The estimated cost of the cleanup effort by Wilson Brothers Construction of Cowley and GeoStabilization International of Grand Junction, Colo., is $653,000.

Wilson and GSI are scheduled to begin work on the rockslide cleanup effort and slope stabilization beginning Monday between mileposts 121.7 and 122.2 – also known as Big Windy Curve – about 10 miles south of Thermopolis.

"The work at Big Windy Curve will include scaling, breaking up large rocks and cleaning the ditches," according to Wyoming Department of Transportation resident engineer Kaia Tharp of Thermopolis. "Rocks and other debris will be hauled south about 13 miles to WYDOT's Birdseye Pit between Wind River Canyon and Shoshoni, and also south seven miles to the Upper Wind River Campground."

Citizens should expect traffic delays of up to 40 minutes, six days a week, during the rock/mud cleanup and emergency repair project, which carries a completion date of July 14.

Wilson Brothers Construction of Cowley was nearly finished with a rock-scaling project started last fall, with the goal of cleaning up the area after the 2015 Memorial Day flooding and mudslides. Wilson Brothers was finishing up its work in early May when the rocks started rolling, sliding and falling again in Wind River Canyon, thanks to near record-breaking moisture in the Owl Creek Mountains.

WYDOT maintenance employees are continuing to monitor and clear the roadway of falling rock, mud and additional cracking in the highway's driving surface, which began to appear in mid-May.

Releases from Boysen Dam into the Wind River were recently increased to 7,000 cubic feet per second (cfs), and County Emergency Management Coordinator Bill Gordon recently noted the flows could be up to 8,000 cfs or more, depending on how fast the reservoir fills; inflow into the reservoir from April through July is forecasted to be 1.5 million acre-feet.

Gordon further noted the walls in the canyon could be at a point of saturation where any significant rain or snowfall could cause additional slides.