They warned it would happen again — and on Saturday it did.
Mudslides buried Interstate 70 through Glenwood Canyon on Saturday afternoon, prompting the Colorado Department of Transportation to shut down the heavily traveled route during the busy Fourth of July holiday weekend.
Both westbound lanes of the highway opened Sunday morning. The eastbound lanes are not expected to reopen until 7 p.m.
“If we can beat that, obviously, we will,” said Kane Schneider, CDOT deputy superintendent of maintenance for the region that includes Glenwood Canyon.
The bike path that runs parallel to the highway is covered in 10 to 12 feet of debris and will be closed for an extended period, Schneider said.
Five areas east of the Hanging Lake tunnel slid on Saturday. These drainages are different than the areas the slid last weekend.
The slides happened at about 3:30 p.m. Saturday, just after a flash flood warning from the National Weather Service. They were spread along a 2 mile stretch of the canyon, CDOT spokeswoman Lisa Schwantes said during a briefing Sunday morning. Some areas were covered with mud, rocks and vegetation 9-feet deep.
It took about 19 hours of nonstop work to open the westbound lanes, Schwantes said. “Our crews are dealing the a challenge of very sloppy, wet, messy material.” One operator described the muck as “difficult to corral,” she said.
A few dozen motorists who entered the canyon just before it was closed were trapped between the slides for a couple of hours, though Schneider said no one was injured and all the cars were able to drive out of the canyon. He said a few cars also were trapped last weekend.
Glenwood Canyon has been susceptible to mudslides since the Grizzly Creek fire burned more than 30,000 acres in and above the canyon last summer. Mapping last summer identified 20 drainages where heavy rains might lead to debris flowing down to the highway.
Bob Group, a CDOT geohazards program manager, said the highway department is using aerial imagery from the mudslides to determine if there are ways to mitigate the hazard, but the work is complicated. “We are in a tight, narrow canyon,” he said. “There isn’t a footprint to install a lot of mitigation.”
This is the second I-70 closure through the canyon recently because of mudslides. CDOT has begun shutting down the route when there is a flash flood warning in effect as a precaution.
Motorists are encouraged to detour around the canyon through Steamboat Springs, which adds about 2.5 hours in travel time. CDOT workers are stationed on I-70 in Rifle to make sure commercial vehicles take the detour rather than trying to navigate the narrow Independence Pass outside of Aspen.
Motorists can check cotrip.org for the latest information on closures and detours.