At about 4 p.m. Thursday a massive avalanche hit Highway 91 by milepost 21, near Copper Mountain. Four cars were trapped in the slide, and there were no reports of injuries.

The avalanche covered about 300 feet of the roadway, with snow about 15 feet deep, said Colin Remillard, a spokesman with the Colorado State Patrol. The people inside the cars were rescued, though the cars are still buried on the roadway.

Remillard said that in addition to the massive avalanche that trapped cars on Highway 91, there were “multiple” others in the same area. Where exactly they occurred or to what extent is currently unknown.

Charles Pitman, spokesperson with the Summit Rescue Group, said at least one vehicle was turned completely upside down and totally buried.

The Colorado Department of Transportation said the road would remain closed overnight.

“Natural avalanche on CO 91 was on Resolute Cliff, a path that has NEVER run before & is on the opposite side of the rd,” CDOT said in a Twitter update. “We have not done mitigation on this path in the past.”