Idaho Transportation Department
07/23/2026 | Press release | Distributed by Public on 07/23/2026 09:42
SH-21 closed from Grandjean to Banner Summit after mudslide
7/23/2026
Jill Youmans
ITD Communication
208.334.8303
[email protected]
SH-21 closed from Grandjean to Banner Summit after mudslide
BOISE COUNTY - State Highway 21 remains closed from Grandjean to Banner Summit after a mudslide covered the roadway yesterday.
The closure extends from milepost 94 to milepost 105. Crews are on site assessing the slide, and heavy equipment is being brought in to begin cleanup.
With more rain in the forecast, the highway could remain closed for a week. Crews will work to reopen the roadway as soon as it is safe to do so. Drivers should not attempt to travel through the closure area. The Idaho Transportation Department will continue to provide updates as conditions change.
Travelers are encouraged to check 511.idaho.gov or the 511 mobile app for the latest closure information before heading out.
Idaho Transportation Department published this content on July 23, 2026, and is solely responsible for the information contained herein. Distributed via Public Technologies (PUBT), unedited and unaltered, on July 23, 2026 at 15:42 UTC. If you believe the information included in the content is inaccurate or outdated and requires editing or removal, please contact us at [email protected]