Rock fall below the face of a sandstone cliff that collapsed recently at Pictograph Cave State Park east of Billings, damaging the access road and closing the park indefinitely. (Picture courtesy of Fish, Wildlife and Parks)
A rockslide last week has resulted in the closing of the Pictograph Cave State Park indefinitely, according to Montana Fish, Wildlife and Parks. The face of a sandstone cliff overlooking the park collapsed, sending boulders over the roadway and a hiking trail. While no injuries were reported, and no buildings were damaged by the rock fall, the park will remain closed until the roadway can be repaired.
Boulders, ranging in size from a basketball to twice as big as a car, were strewn at the base of the cliff and across the access road and a hiking trail. The rocks have been cleared off the roadway, but the surface of the road remains damaged. According to Robert Gibson of Montana FWP, the actual caves were not damaged. Some rocks landed on the switchback trail to Ghost Cave, the northernmost cave of the three, but there was no damage to the caves themselves.
“We do not doubt that this was caused by natural phenomenon. The water gets behind these rocks and then goes through a series of freezing and thawing until they break off,” stated Gibson. “It is fairly common with the sandstone cliffs and rims we have in the area.” Geological engineers will assess the likelihood for additional rock slides which could cause damage or injury. The park will remain closed to the public until those assessments are completed.
