The rockslide left a debris field approximately 120 feet long and 40 feet deep at the base. Some rocks measured 25 feet across and were reported to be "just as tall."
Carmen Escalera and her family were traveling along the roadway when they captured the dramatic scene on camera.
Initially, several rocks fell from the adjacent cliffside, followed by an avalanche of rocks.
According to the Idaho County Sheriff’s Office, the route closed indefinitely on Friday, making north-south travel inaccessible to Fourth of July travelers.
ITD officials initially said they hoped to open a temporary roadway by Sunday, but discovered a crack in the rock face up above.
“The very nature of slides is unpredictable,” operations engineer Jared Hopkins said.
Geotechnical surveys conducted on Monday showed "significantly less" movement on the slope, but officials were having outside experts examine the area to identify short-term and long-term options to stabilize the area.
“When survey results and on-slope evaluations prove that the slide is stable, we will look to open the highway for short periods of time,” Hopkins said in a news release. “In the meantime, we are evaluating the condition of Old Pollock Road to see how we may be able to help the county with a locals-only detour.”
A temporary roadway has been constructed around the slide, and barriers have been placed to protect drivers from any further rockslides.