MYRTLE, ID –  U.S. Highway 12 near Arrow Bridge will close at noon on Friday, Nov. 21, as Idaho Transportation Department crews begin emergency rock-scaling work to remove unstable material from the hillside above the roadway.

The full closure will remain in place around the clock until crews finish dislodging and hauling away loose rock. Because slope conditions can shift during the operation, ITD cannot provide an exact reopening time. Officials say the work is not expected to affect Thanksgiving travel.

Traffic will be detoured to alternate state routes, including U.S. 95, State Highway 3, State Highway 13, and State Highway 162.

“The decision to close the highway was made from a safety standpoint to protect travelers from falling rocks and to allow for a timelier cleanup process,” said Jared Hopkins, Operations and Traffic Engineering Manager. Heavy equipment will load and remove rock debris as it comes down.

Motorists should also expect increased truck activity near Cherry Lane Bridge and the south end of Arrow Bridge, where trucks will be entering and exiting the roadway.

Slope-monitoring has been underway since Tuesday, and flaggers have been in place to assist traffic. Drivers are asked to follow posted signs and use detour routes.

For updates, visit 511.idaho.gov, call 511, or use the Idaho 511 app.