It’s rockslide season in the Rockies

CDOT working hard as spring thaw pushes rocks down canyon walls

A March 26 rockslide causes a single lane closure on I-70 between Wolcott and Eagle.
David Hakes | Vail Daily

VAIL — We live in the Rocky Mountains and no one should be surprised when some of those rocks obey the laws of gravity with great zeal.

It’s rockslide season and the Colorado Department of Transportation is keeping an eye on the sky — and the rock walls from whence those rocks roll.

“We’re seeing an active rockslide season. It’s that time of year,” CDOT’s Tracy Trulove said.

CDOT crews monitor 750 sites around the state that they identify as potential rock fall areas.

“That’s probably more than people realized,” Trulove said. “And it’s probably not all of them.”

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A rockslide in February did not originate in one of those 750 sites. That was the one on March 18 that blocked both westbound I-70 lanes at Dowd Junction.

CDOT maintenance workers are driving the highways all the time. Maintenance teams are also always keeping an eye out.

But Colorado is a big place, and there is a limited number of CDOT staffers.

“It’s so much territory to cover that we also depend on the traveling public,” Trulove said. “We ask them to all 911.”

Rockslides are a risk

Rockslides are an inherent risk of traveling during the spring in the mountains when freeze/thaw cycles are cycling. Moisture gets behind rock on canyon walls, and as the water expands and contracts with the changing of the seasons, it eventually pushes rock away from that canyon wall.

Gravity does the rest.

However, rockfall is sporadic, unpredictable and can occur at any time from almost any location along a slope. The purpose of implementing rockfall mitigation is to reduce the risk of rockfall at a specific location, says CDOT’s geohazards team.

The geohazards team is five people who respond to incidents around the state.

They also work with contractors to do rockfall mitigation — make the rocks fall when and where they want them to, instead of waiting for them to come crashing down.

The engineers and scientists in Colorado’s geohazards program provide geological expertise for rockfall, rockslide, mudslide and landslide geological hazard mitigation, design, construction and planning.

To help keep an eye on things, the Colorado Geological Survey (CGS) is now handling distribution of the Colorado Rockfall Simulation Program.

“Having as much moisture as we had this winter could mean a more active rockslide season,” Trulove said.

People were wound up about the winter’s avalanches, but hopefully that moisture will stifle the area’s wildfire season, preventing a repeat of last year.

“We hope,” Trulove said.

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