240 Ton Boulder Blasted at Mesa Verde

240 Ton Boulder
240 Ton Boulder Before Blast

On February 22, 2012, between 6:30 and 7:30 a.m., a large slab of rock broke loose from the cliff face above the park’s road, about three miles from the park entrance. As the slab fell, it broke into large boulders that scattered over a 150-foot wide path. One 20-ton boulder landed on the road and left a 240-ton boulder teetering 80 feet above the highway on a bed of soft soils and packed snow.

Due to the precarious nature of the boulder, park staff determined it would be necessary to reduce its size by blasting. On Monday, February 27, 2012, Franklin Drilling and Blasting from Durango reduced the size of the boulder with a controlled, single load blast that shattered the rock into small, manageable pieces from the inside out. The blast removed the top six to eight feet of the rock, approximately 100 tons of mass. It took 2.5 hours to drill the holes, insert explosives and detonate the charge. Park staff was on site to remove debris from the roadway. The video of the blast may be viewed here. (Video Credit / Author: NPS/Frank Cope, Date Created: 2012-02-27)

“We are glad that no one was in the area when the slide occurred.” stated Superintendent Cliff Spencer. “It serves as a reminder for park staff and the public alike that warning signs in the park are for staff and visitor safety.” There are multiple signs cautioning drivers not to stop or park anywhere along that stretch of road. Visitors are also warned of winter driving conditions this time of year and to watch for wildlife at all times.

Source: NPS

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