Interstate 70 through Glenwood Canyon has been closed since about 9:30 p.m. Monday after a second rockfall in less than 24 hours occurred about 8 miles east of Glenwood Springs. The road is closed in both directions this morning with no estimated time to reopen.
"I expect a lengthy closure," Tracy Trulove, Colorado Department of Transportation regional spokeswoman said at 6 a.m. Tuesday as she drove into the canyon. "This is as big as I've seen" in her two and a half years in her role.
She said a semi was seriously damaged in the incident Monday evening, but no one was injured.
The rocks fell from very high in the canyon, and CDOT decided to close the road for the night rather than putting workers in harm’s way trying to clear I-70 at night, Trulove said.
The road was closed between Glenwood Springs and Gypsum. Trulove advised commuters to checkcotrip.org, @ColoradoDOT on Twitter or Postindependent.com for updates today.
The Colorado State Patrol tweeted to expect "extreme delays" and to plan alternate routes on U.S. Highway 40 through Craig and Steamboat Springs and state highways from the east, or U.S. 50 and state highways from the west.
Monday saw two large rockfalls in the canyon. Large rocks fell in the same place at about 2:40 a.m. Monday, forcing a full closure of the road until about 5 a.m. Then, as workers broke up those boulders, moved debris off the highway and used temporary patch material, traffic ran in both directions in the left lanes only.
That incident was cleared a bit after 7:30 p.m., when all four lanes of I-70 were reopened, only to be closed two hours later. No one was hurt in the first incident.
Trulove said a CDOT geologist was in Glenwood Springs Monday night and was planning a helicopter flyover of the area this morning.
In the first incident, large boulders broke off of the north side of the canyon west of the Hanging Lake exit, where the westbound lanes are positioned above the eastbound lanes. Rocks tumbled across the westbound roadway and over the edge onto the eastbound lanes — and at least one boulder had enough velocity to land on the south bank of the Colorado River.
Colorado Department of Transportation crews required intermittent stops on I-70 during clean-up of the first incident.
The rocks were large enough that CDOT used “Boulder Buster” equipment to break them down and remove them. Crews used jackhammers to drill into the large boulders and placed a type of ordinance similar to a shotgun shell to crack the rocks, Trulove said.
Road crews used a temporary cold patch mix where the boulders had taken chunks out of the asphalt. Trulove said CDOT will have to wait until the “hot batch asphalt” plants start operating in the spring.
The incidents came after a season of mitigation efforts by CDOT, but Trulove doubted that more fencing in that area would have stopped the boulders because they fell from so high.
Crews moving rocks and filling in damaged asphalt, where the chances of move boulders crashing down was still high, surmised that the rocks had broken off near the top of the canyon’s northern rim.