A massive rockslide punched van-size holes in the decking of Interstate 70, closing the highway in both directions all day on Thanksgiving and sending holiday travelers on a 220-mile detour to get through the mountains. There were no injuries, but Colorado Department of Transportation officials said they were hoping to open one lane in each direction by late Thursday night and said final repairs to the highway could take weeks or even months. CDOT suggested that drivers use U.S. Highway 40 and State Highway 13 to get around the canyon (see alternate routes above). Some motorists tried to take Cottonwood Pass between Missouri Heights and Gypsum, but CDOT officials said there was too much snow on the high dirt road, prompting them to close the back route. On Thursday at noon, CDOT deputy maintenance superintendent Del French said he anticipated that once the highway reopens – which could happen today or it could take longer – it will only be able to accommodate one lane of traffic in each direction. “We anticipate bottlenecking,” he said. “What we’ve got here is obviously a substantial rockslide that caused substantial damage. It could be a couple of months before it’s fixed.” The slide zone was estimated to be up to 100 feet long and eight to 10 feet deep. Between 30 and 40 boulders came down the canyon’s steep north wall.Many CDOT employees were unexpectedly called into work on the holiday, trading family, turkey and football for backbreaking labor while trying and get the main thoroughfare through Colorado’s mountains back open for traffic.No doubt, a lot of holiday travelers also were caught off guard as they tried to make their way through the canyon to celebrate Thanksgiving with loved ones. According to a CDOT news release, two bridges have holes in their decks on eastbound I-70. On the westbound lanes there is also significant damage. CDOT estimates that about six boulders were embedded up to eight feet into the roadway. Also, two retaining wall panels along the westbound lanes were completely knocked out.The slide happened about 7:30 a.m. Thursday, just yards east of the Hanging Lake exit offramp at mile marker 125 and about a half mile east of the Hanging lake Tunnels. French guessed that the rocks fell from about three-quarters up the canyon wall, hundreds of feet above the highway. “We’re trying to evaluate when we can open the road up. As you can see, we’re a long way away from it,” French said. CDOT bridge engineer Mark Leonard was on the scene checking the structural stability of the bridge that supports the eastbound lanes and the “T-wall” that supports the westbound lanes. “He’s checking to see if we will be able to open the bridge and if there is lateral stress,” French said. “Rocks are laying against the girders.”At 4:30 p.m. Thursday, CDOT spokeswoman Stacey Stegman said Leonard found no significant structural damage to the highway’s substructure. The two rocks that caused the most damage, each the size of a van, ended up at the bottom of the Colorado River. The rocks punched holes through the road, damaging large sections of guardrail. The westbound lanes had a gaping hole about 25 feet wide and 10 feet long.Cracks in the highway were also visible, stretching up to 20 feet from the edge of the mammoth hole. “Whenever you have a crack like this,” French said as he pointed to the largest one, “we have to excavate out to do a preliminary repair, then we’ll evaluate it.”The most damage to the highway was caused by two van-sized boulders when they pounded the I-70 deck, broke the median barrier, then crashed through the guardrail before rumbling into the bed of the Colorado River. Trails of damage could be seen across the river where the rocks apparently flew over the river and hit the other bank before rolling down to the water. Other rocks on the highway were piled 10-12 feet high in some areas. Boulders too large to be scooped up by front-end loaders were blasted apart by CDOT workers. “They drill one hole into the rock, put primer down in it, then they have these things like shotgun shells and they stack them,” French said. In the background, a worker yelled, “Fire in the hole,” pulled a string, and in a cloud of dust, the rocks were blasted into several pieces. “We’ve got to get them to a size where we can use them,” he said. The smaller pieces were then picked up by front-end loaders and temporarily stored on the Hanging Lake exit offramp. “We’re just cramming them down here. The hanging Lake rest area will be closed for a while. We just don’t have time to haul them out,” he said.When talking about his missing traditional Thanksgiving television staples such as the Macy’s parade in New York City, French commented. “There ain’t no parade comin’ through here.”Contact Greg Mass: 945-8515, ext. 511gmasse@postindependent.com