Bulletin Staff Report

U.S. Forest Service crews are marking dead and dying trees they plan to remove alongside a 12.5-mile stretch of U.S. Highway 20 near Sisters.

About 2,100 trees, mostly ponderosa pines, were killed by the herbicide Perspective, which was improperly sprayed alongside the highway to kill flammable roadside weeds.

Forest Service officials first noticed dying trees in 2014 and said they continued to die after the spraying ended in 2015. In February, the Forest Service released a formal decision memo to outline its plan for removing the trees and preventing them from falling onto the highway.

“The abatement of these dead and dying trees will improve public health and safety along Highway 20 and maintain the scenic quality of a National Scenic Byway,” the memo reads.

Traffic on the highway will be affected when the Forest Service starts removing the trees April 29, said Peter Murphy, Oregon Department of Transportation spokesman.

The traffic impact is still being determined, but long-term closures of the highway are not expected, Murphy said.