CDOT is using 30-pound bombs to dislodge rocks that have kept U.S. Highway 550 closed since Jan. 12. The closure has severed the only direct route from Ouray to Silverton, normally a 70-mile drive over Red Mountain Pass. A detour over Dallas Divide and Lizard Head Pass adds 98 miles to the trip. Officials say a giant slab about the size of a football field came loose and crumbled into smaller pieces, that covered the highway. It’s unusual for slides to occur in the middle of the winter, but the unseasonably warm temps caused a freeze-thaw cycle that contributed to the slide. Crews will work through this weekend. The reopen could come next week.