ROADS/BRIDGES: Mountainous I-70 closed down due to massive rockslide

“Smart-car-sized boulders” came tumbling down Glenwood Canyon in Colorado, closing down a 24-mile mountainous stretch of I-70 and forcing thousands of motorists to take a 146-mile detour.

The Colorado Department of Transportation (CDOT) first analyzed the canyon walls at the rockslide site and reopened I-70, but had to close it down again just 19 hours later when more large boulders fell onto the road.

Some of the boulders that landed on I-70 are so large that they must first be blasted with explosives so that pieces can be loaded onto trucks and hauled away.

Over the last 12 years, the same stretch of I-70 has seen four rockslides. CDOT has a $9 million rockfall program aimed at monitoring the over 750 Colorado locations that have chronic rockfall hazards. Those funds pay for netting, visual monitoring and rock removal, among other remediation.

The closed interstate will partially reopen but a full reopening is has not been announced. The cost of repairing the interstate is being determined.