Updated 5:19 p.m.
I-70 will be open again by 6 p.m., after rockfall closed lanes in both directions for much of Friday, according to CDOT.
This morning, a rock slide closed the westbound lanes of Interstate 70, creating delays for people heading from the Denver area to Colorado ski areas.
Parts of eastbound I-70 starting in Frisco closed around noon so crews could conduct blasting to prevent further rockfall, according to CDOT. Eastbound lanes reopened just before 4 p.m.
Colorado Department of Transportation officials said Friday that westbound vehicles between Beaver Brook and Dumont are being turned back, and that the closure and delays may be extensive. CDOT spokesman Matt Inzeo said they anticipated it'd be another few hours before westbound lanes reopened.
"This closure is a tough one," he said. "We certainly understand people's frustration, but we're looking to keep the public safe. Seek alternate routes if you absolutely have to get eastbound or westbound through the mountains."
The alternative route from Summit County is U.S. Highway 285, but that is also likely to experience delays.
This same section of rock face closed the road earlier this week, causing significant delays for holiday travelers. Matt Inzeo said freeze-thaw cycles have loosed the rock. CDOT has protections in place on that stretch of road already, and fencing and netting is catching most of the rock. But Inzeo said the danger of falling rock during such a busy travel period is still too high to risk letting people through.
More snow is expected to arrive Friday afternoon, along with strong winds that could make driving conditions more dangerous. People heading to the mountains should expect significant delays.