The Idaho Transportation Department will close State Highway 21 north of Grandjean tomorrow as additional rain enters the area to address ongoing safety hazards caused by recent landslides.
Though a closure was initially scheduled for Oct. 7, anticipated increased rainfall will continue to destabilize the area, triggering additional mudslides that threaten motorists and ITD crews. To protect the public and allow for emergency repairs, the highway will close with the storm’s arrival tomorrow. Crews expect to reopen the road by Wednesday. The area is experiencing increased slope instability due to burn scars left by the Wapiti Fire.
During the closure, crews will complete the previously scheduled emergency repairs caused by the August 2025 landslide, which plugged an existing culvert and diverted Canyon Creek to the east side of the highway. The creek is now flowing along the shoulder and eroding the road. Installing a new six-foot culvert across both lanes will restore the creek to its natural channel and protect the roadway from further erosion.
For updates on traffic conditions and closures visit 511.idaho.gov or download the Idaho 511 mobile app.