CO 119 in Boulder Canyon closed indefinitely due to major rockfall from blast

BOULDER — Colorado Highway 119 in Boulder Canyon will be closed indefinitely – at least for 24 hours -  following a massive rockfall during regular blasting for the project. 

Usually a blast brings down about 400 cubic yards each time. Today’s blast sent approximately 8,000 cubic yards of rock down the side of the mountain and on to the roadway. A cubic yard is about the size of a normal washing machine.

Some of the rock is too large to be moved and additional blasts will be needed to break it up before it can be taken away. (See photo attached below). There were no injuries as the area was clear due to regular safety protocols during blasting.

In addition to this rockfall, CDOT geotech officials have found another area of rock that was loosened in this blast that will need to be blasted out to ensure the roadway is safe for regular traffic. Crews will be working overnight through this process to clear the road as soon as possible. 

Boulder Valley School District has plans in place to get school buses to the affected residences. There are local detours available and Colorado Highway 72 is the main way for people to bypass this area. RTD has also been contacted and will determine bus routes accordingly.

The blasting that was happening was NOT to mitigate rockfall. This was part of the CO 119 flood construction project. We are blasting into the mountain to move more of the road on to bedrock so it will survive during the next major flood.