A rock slide on Interstate 70 near Glenwood Springs, Colo., punched holes in a bridge and dumped boulders the size of semitrucks on the highway, closing a 17-mile stretch of the road on the morning of March 8. There were no injuries. The slide occurred at midnight, just west of the Hanging Lake Tunnel in Glenwood Canyon, scattering approximately 20 boulders ranging in size from 3 ft to 10 ft in diameter. The largest is estimated to weigh about 66 tons. Colorado Dept. of Transportation geologists attributed the slide to a freeze-thaw effect caused by warm spring weather. CDOT implemented emergency contracting procedures, while it continued to develop repair plans and seek bids, which it expects to receive in the next few days.