EVERGREEN – Highway crews detonated 4,400 pounds of explosives packed into 150 holes drilled into Clear Creek Canyon west of Denver on Tuesday, blowing up clouds of dirt and loosening 5,000 cubic yards of rock above Interstate 70 as they ramped up work on Colorado’s $800 million project to straighten some of I-70’s tightest and most treacherous curves. Colorado Department of Transportation coordinators working with local police stopped traffic.