Road crews hope to re-open a single lane of traffic in each direction today on Interstate 70 between Glenwood Springs and Gypsum. But the highway could remain obstructed for weeks after an extensive rock slide Thursday.

Workers, under the glare of portable spotlights, toiled through the night to clear part of a highway in western Colorado after a Thanksgiving Day rock slide sent boulders as big as vans crashing on to the pavement. More than three dozen boulders landed on Interstate 70 early Thursday, some embedded 6 feet deep. State officials ended up closing a 24-mile section of the main east-west artery through Colorado and rerouting traffic between Glenwood Springs and Gypsum almost 220 miles to the north and through the Rockies. Geologists and engineers were working alongside the crews, trying to figure out what caused the slide.

No one was hurt in the slide, estimated to be 100 feet long and 10 feet deep, thanks perhaps to a truck accident earlier in the morning.

An overturned truck had forced authorities to temporarily close the interstate earlier Thursday. They were preparing to reopen the road when rocks began rumbling down the canyon walls a mile away.

For the state's latest road conditions, visit the Colorado Department of Transportation.