CLEAR CREEK COUNTY, Colo. — Three major highways in the mountains were closed on Tuesday morning for avalanche and rockfall mitigation work, the Colorado Department of Transportation said.

The biggest closure was both directions of a 27-mile stretch of Interstate 70 between Empire and Silverthorne.

The interstate was closed when CDOT crews triggered an avalanche, resulting in a larger-than-expected amount of snow crossing all lanes of traffic about 8:45 a.m. near Herman Gulch, about three miles east of the Eisenhower Tunnel.

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CDOT said 15 feet of snow covered westbound lanes and 8 feet in the eastbound lanes. CDOT said the closure will last into the early evening because of the significant debris field that included several trees and rocks.

Significant damage was done to cable rail in the area and it needed to be repaired. There were no reported injuries.

U.S. 6 was also closed in both directions between Arapahoe Basin Ski Area and the summit of Loveland Pass for rockfall mitigation. The closure was expected to last until 5 p.m.

CDOT closed U.S. 40 over Berthoud Pass at 8 a.m. Tuesday for a few hours avalanche mitigation. CDOT said the last time mitigation hit U.S. 40 was in 1957.

Interstate 70 was also closed for a helicopter mitigation effort in Ten Mile Canyon between Frisco and Copper Mountain, where there have been several slides since a major winter storm dropped several inches of snow in the mountains over the weekend.

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