A bridge at the downstream boundary of Hoback Canyon is threatened by swift-moving water that’s scouring away rocks, cobble and sediment at the base of its piers.
The Stinking Springs bridge’s integrity is compromised enough by the Hoback’s fluctuating flows that the Wyoming Department of Transportation plans to shore up the riverbanks and bed beginning next summer. The work is complicated by the fact that the lowest 10 miles of the Hoback are classified as “recreational” under the protective Wild and Scenic Rivers Act.
“The Wild and Scenic River Act requires us to be conscientious of the water flows and the surrounding landscape,” WYDOT District Engineer Keith Compton said in a statement. “We do not want to drastically affect the aesthetics or the physical characteristics of the river.”
Exactly how the stabilization work will be conducted and designed differently to comply with the act remains to be seen. WYDOT is navigating a “Section 7” review with the Bridger-Teton National Forest, which is meant to ensure the work does not drastically affect the Hoback’s scenic characteristics, spokeswoman Stephanie Harsha said.
The bridge over the Hoback itself is not being modified, Harsha said. That structure was built in the 1970s and typically has a lifespan of 70-plus years.
It’s not yet clear how, or if, the river work will affect traffic on Highway 189-191. Those decisions will be made by the contractor that is awarded the job, which includes other bridge rehabilitation projects throughout WYDOT’s 3rd District, which spans from Evanston to Wamsutter to the southern Yellowstone boundary.