With cleanup complete and the threat of further rock slides mitigated, the Colorado Department of Transportation (CDOT) reopened Interstate 70 through Glenwood Canyon this afternoon. The highway had been closed since Monday when a slide sent 250 tons of rocks crashing onto the interstate.

Boulders the size of semi-trucks did significant damage to the interstate. A hole on the westbound sound measured 20 feet by 10 feet and one on the eastbound side was 6 feet by 6 feet.

While in the process of starting the cleanup, CDOT geologists discovered additional rocks further up the mountain that presented a threat to the highway.

• Slideshow: I-70 rock slide cleanup completed; Interstate re-opens

Crews worked in recent days to remove one rock that was 20 feet in diameter and smaller threats on the mountain while others worked to repair the roadway below.

The extensive damage caused to the highway will result in limits on traffic through the affected area for the near future. Only one lane in each direction is open now and the speed limit has been reduced to 40 mph. Trucks over 14 feet wide are not permitted in the area.

CDOT said they would provide more information tomorrow as to how long complete repairs will take. In a statement they said the new restrictions “will remain like this until long-term repairs can be completed in the coming weeks/months.”

Slides in Glenwood Canyon are not entirely unusual due to the rugged terrain and the varying weather conditions experienced in the area. Storms, snow melt and runoff, and even minor seismic activity can set loose the sides of mountains.

The stretch of I-70 through Glenwood Canyon was the final piece of the interstate highway system to be completed in the United States. When it was finished in 1992 the 15-mile stretch was considered a major engineering accomplishment.

A rockslide that dropped boulders the size of semi-trucks has forced the Colorado Department of Transportation (CDOT) to close I-70 in both directions. Officials are unable to provide an estimate on when the road will reopen as damage is extensive on both east and west bound sides.

CDOT spokesperson Stacey Stegman said the boulders were big enough to punch holes into the surface of the highway. Some are large enough that moving them as they are may not be an option – they instead will have to be blown apart into smaller pieces.

CDOT reported on Twitter that the boulders ranged in size from 3 to 10 feet with the largest weighing 66 tons. The largest hole on the westbound side of the highway measures 20 feet by 10 feet and the largest on the eastbound side measures 6 feet by 6 feet.

• Slideshow: Monstrous rockslide forces closure of I-70 in Colorado

The slide occurred near mile marker 125, west of Hanging Lake Tunnel. Officials said they were lucky the slide occurred at 12:09am when traffic on the highway was at a minimum.

Interstate 70 is closed in both directions between mile markers 116 and 133. CDOT says it could be a couple of days before traffic is able to utilize the route.

The shortest detour around the slide area is not a quick one requiring nearly a 200 mile route. Drivers are being encouraged to use U.S. 40 through Steamboat Springs or U.S. 50 through Montrose and Gunnison.

For more on this story including the history of putting I-70 through the canyon, please visit the Denver Weather Examiner.