Major highway to Central Oregon will close Aug. 2

A major highway through the Cascade Mountains will be closed for six to eight weeks, limiting the number of roads people can travel from the Willamette Valley to Central Oregon and back.

The Sheep Creek Bridge on U.S. Highway 20, about 25 miles east of Sweet Home, is being rebuilt to mitigate impacts from a major landslide. Work begins Aug. 2.

All traffic traveling from Corvallis to Sisters will need to use alternate routes such as Highway 22 (east of Salem) or Highway 126 (east of Eugene) to reach Santiam Pass and Central Oregon.

The bridge will be closed to traffic at milepost 54.40 for eastbound traffic and at milepost 56.95 for westbound traffic. Campgrounds and trailheads in the South Santiam area will remain open, but might need to be reached from an alternate route.

The popular Iron Mountain Trail, for example, located at milepost 64 on Highway 20, won’t be accessible from the west side near Corvallis and Sweet Home. To reach it, visitors will have to arrive from the east and Santiam Junction area.

“The bridge itself is located on an active landslide that is huge — and that has become more active,” said Jerry Wolcott, project leader for the Oregon Department of Transportation, in a video posted on YouTube. “The landslide has been pushing against the bridge since it was built in the 1960s, and now has pushed it to a degree that we’ll have to replace the east end.”