The Arizona Department of Transportation will begin the last phase of its geotechnical investigation into the landslide on the US 89 highway.
According to a release, heavy construction crews started Tuesday and will begin excavating a path accessible for engineers to dig holes from 10 to 15 feet deep and 20 to 40 feet long. ADOT has considered the Navajo Route 20 as a provisional detour pending the completion of US 89's repair work.
Steve Boschen, ADOT deputy state engineer of design, explained that the construction will allow experts to determine the best available options including either readjusting the highway or rebuilding the current road.
"ADOT's goal is to repair this critical section of highway and restore connectivity throughout the region as soon as possible. But before we can start the repairs, we need to determine the cause of the landslide and assess the safety of the slope."