BRECKENRIDGE, Colo. - The Colorado Department of Transportation plans to shut down a stretch of Interstate 70 during the day April 5 and 6 while crews attempt to remove a potentially dangerous cluster of rocks from a ridge above Georgetown.
Though the exact details of the closure are dependent on weather and the severity of the situation, CDOT expects to completely close the highway in both directions from Silverthorne to the Empire Junction/US. 40 exit from 9 a.m. to 5 p.m. on Tuesday, April 5 and Wednesday, April 6.
"None of this is going to be entirely firm because we're dealing with a situation that we're not entirely sure about until we actually get up there and start working," CDOT spokeswoman Stacey Stegman said. "We don't know what we're going to find."
The cluster of about 40 rocks, ranging in size from 2 to 16 feet in diameter is located about 300 feet above the highway at the frontage road near Georgetown.
CDOT became aware of the problem within the last month, but could not secure a helicopter necessary for the work until next week due to recent wildfires. In the meantime, transportation officials said they can't determine or reduce the risk of the rocks falling on the highway or nearby residences.
"We can't say with certainty what the risk is," Stegman said. "That's why we're moving quickly to get those rocks down. There's always potential for rocks to fall. All we do is reduce the probability."
CDOT and Clear Creek County officials said some Georgetown residents will be evacuated during the work as a safety precaution.
The closure has Summit County officials concerned about emergency vehicle access as well as visitor travel during a busy two-day period when the county has high lodging occupancy numbers, officials said at a Summit Board of County Commissioners meeting Tuesday in Breckenridge.
There are only two alternate routes around the closure, over Hoosier Pass and Berthoud Pass, both of which are significantly longer than the I-70 route.
"Our biggest concern is emergency access," assistant county manager Thad Noll said. "We're concerned about the resorts and the businesses."
Emergency vehicles will be allowed through the stretch if necessary.
Both Copper Mountain and Beaver Creek have events planned for April 5 and 6, Noll said.
Summit County officials are also worried about the location of the closures, as vehicles that try to wait the closure out might not have access to restrooms, gas stations or other facilities from where they stop when traffic begins to back up.
There are no alternative times when the road can be shut down, as the work cannot be done at night, and crews need at least eight-hour periods to do the work, Stegman said.
Information about the closure was not released to the county until Friday, when a note was included in a weekly memorandum on work in the corridor.
"Our real beef isn't that they're closing down the highway," Noll said. "We know that if you've got a big problem, you've got to close the highway. However, the way (they're) getting the word out is not good. We have information about what's going on here that will help them in their decision making, and it would (have been) useful if we were able to exchange information before this."
Summit and Clear Creek County officials, ski resort representatives, CDOT and others discussed the closure during a 90-minute closed conference call Tuesday. Another talk is set for later this week, Noll said.
CDOT has procedures in place to try to prevent falling rocks from damaging the highway while the work is being done, Stegman said.
If necessary, the work will be continued April 12, according to the CDOT memo sent out Friday.
The rock cluster developed through erosion caused by water and the freeze-thaw process. CDOT has ongoing rockfall mitigation projects in the area.