SH-21 to close for two days north of Grandjean for culvert installation

STANLEY -The Idaho Transportation Department will close State Highway 21 north of Grandjean Tuesday at 7 a.m. for two days to complete emergency repairs caused by the August 2025 landslide. The closure will last for two days, with the roadway scheduled to reopen by 6 p.m. Oct. 8.

Mud from the recent landslide plugged an existing culvert, diverting Canyon Creek to the east side of the highway. The creek is currently flowing along the shoulder and eroding the road. To protect the highway and restore the creek to its natural channel, crews will install a new six-foot culvert across both lanes.

"This emergency repair is absolutely vital," Operations Engineer Michael Garz said. "Closing the highway for two days allows crews to complete the culvert installation safely and quickly, minimizing long-term impacts and preventing a potential longer closure later."

The new culvert will also handle potential overflow during future high-water events, which are likely due to burn scars from the Wapiti Fire. Any other details to insert here?

For updates on traffic conditions and closures visit 511.idaho.gov or download the Idaho 511 mobile app.