It may take up to a week to clear a massive rockslide that came down early Sunday on U.S. Highway 550 about 10 miles south of Durango, the Colorado Department of Transportation said Tuesday.
Crews were trying to determine a cleanup strategy and assess how much damage was done to the highway, said Nancy Shanks, CDOT spokeswoman. They also drilled holes in the rocks in preparation for explosives that are expected to be used Wednesday and possibly Thursday to break the rocks into smaller pieces so they can be carried away.
The rockslide occurred Sunday morning near mile marker six on Bondad Hill. An estimated 700 tons of rock came down, which will require about 70 dump-truck loads to remove, she said. The 150-foot slab broke into several pieces, including one that was 25 feet, by 40 feet by 10 feet in size, and another that was 15 feet by 30 feet by 10 feet.
The highway department expects to need two truckloads of asphalt to repair the road.
Drivers can expect periodic traffic holds or single-lane alternating traffic from 9 a.m. to 5 p.m. this week, she said. That will allow equipment to come and go, and create a safe zone for blasting, Shanks said. Crews will try to restore two lanes of travel by 4 p.m. each day.
Drivers should expect traffic delays up to a half hour, she said.