Interstate 70 near Glenwood Springs remains closed after a rockslide smashed through a bridge and dumped boulders the size of tractor trailers on the highway early Monday just west of the Hanging Lake Tunnel.

Detours of up to 200 miles could last for days, if not weeks, before the 17-mile stretch of interstate re-opens, the Colorado Department of Transportation said this afternoon.

No injuries or damage to vehicles were reported.

CDOT geologists made the two-hour hike each way to inspect the slide area this afternoon, finding that it remained unstable. Officials will meet Tuesday to decide a course of mitigation and estimate when the interstate might reopen.

Gov. Bill Ritter this afternoon declared a disaster emergency in order to ask for money from the Federal Highway Administration to help pay for repairs. A similar slide in the same area in 2004 cost $700,000 to repair.

“This is very similar in size, but we think it has caused even more damage than that one did,” said CDOT spokeswoman Stacy Stegman.

In 2004, I-70 reopened the next day, but there was not unstable rock that had to be addressed above the slide, however, according to CDOT.

Ritter’s order called on all state departments and agencies to take whatever actions necessary to speed the work.

“The immediate repair and reconstruction of the damaged highway is vital to the security, well-being, and health of the citizens of the state of Colorado,” Ritter stated in his emergency declaration.

The long detours for truckers will mean extra costs and delays, an industry official said.

“You couldn’t have picked a worse location, because there is no work-around. That is one of the real choke points in the system,” said Greg Fulton, president of the Colorado Motor Carriers Association. “It is not five or 10 miles. This is a fairly significant impact on our end.”

CDOT will implement emergency contracting procedures and meet with contractors over the next couple of days as crews develop repair plans.

As many as 20 boulders, ranging from 3 feet to 10 feet in diameter, hit the interstate. CDOT estimates the largest rock weighs 66 tons and some are as big as semi trucks. The largest stone weighed 66 tons. About 120 feet of steel guard rail and 100 feet of median were damaged.

One hole in the bridge is estimated at about 10-by-20 feet.

All lanes are closed from Glenwood Springs east to the town of Dotsero between mile markers 116 and 125. Up to 25,000 vehicles a day travel that section.

Alternate routes are in effect:

From westbound I-70 exit at U.S. Highway 40/Empire to Colorado Highway 13 and back to I-70; exit in Silverthorne and take Colorado Highway 9 to U.S. Highway 40 and Colorado Highway 13; exit at Wolcott/Colorado Highway 131 to U.S. Highway 40 and Colorado Highway 13.