The staff at Mesa Verde National Park recently found themselves between a boulder and a hard place.
Shortly after 6:30 a.m. on Feb. 22, a large slab of rock broke loose from the cliff face above the parks road, about three miles from the park entrance. According to a news release from the park, as the slab fell, it broke into large boulders that scattered over a 150-foot wide path.
One massive boulder, estimated to weigh 20 tons landed on the road. Another even larger, 240-ton boulder was left teetering 80 feet above the highway on a bed of soft soils and packed snow.
Park staff determined to reduce the size of the boulder by blasting.
Franklin Drilling and Blasting from Durango came in on Feb. 27 and used a single load blast that shattered the rock into small, manageable pieces.
The blast removed the top six to eight feet of the rock, approximately 100 tons of mass. It took more than two hours to drill the holes, insert explosives and detonate the charge.
Park staff was on site to remove debris from the roadway.
We are glad that no one was in the area when the slide occurred, said 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.
The video of the blast may be viewed at www.nps.gov/meve/parknews/12_06_rocking_meve.htm.