Pictographs tumble from cave wall at state park
Three images at Pictograph Cave State Park near Billings broke off and fell to the ground.
"Last week there were 36 pictographs," said Jennifer Lawson of Montana State Parks. "This week there are 33 pictographs."
Officials said the rock fall happened sometime between closing time at 5 p.m. Jan. 18 and 9 a.m. Jan. 19 when a ranger arrived. One of the images found on the ground is the black outline of a turtle.
"It represents the earliest known painted image on the Northern Plains," said Lawson. Turtles are one of the more common images found in regional rock art, she noted, with 31 found in Montana.
Other images that broke off include an abstract image in charcoal, and two pieces of a light red ochre image that experts surmise is likely the headdress and legs of a once larger image.
"We were devastated," Jarret Kostrba, the park's manager, told the Billings Gazette (http://bit.ly/VCs3Tk).
However, the turtle survived almost intact and will become part of a display in the visitor venter.
"Fortunately it did not shatter," Kostrba said.
Workers have been checking on the cave art because of freezing and thawing cycles that expand and contract fissures holding water in the rock. The water, experts say, likely is left over from big snows in the winter of 2010-2011 that saturated the land above the cave and worked its way into the porous sandstone.
"This has been going on for eons," said Kostrba. "I can't imagine what we could have done to prevent it."
Experts say generations of prehistoric hunters, going back 6,000 years, used Pictograph, Middle and Ghost caves because the complex is ideally situated near a fertile river valley. Park staff and volunteers have been recording conditions in the cave that last few years.
"We're going to work with experts to see what can be done," said Chas Van Genderen, administrator of the state parks department. "We'll do anything we can within our budget and our capacity. But it's a very complicated problem. It's hard to beat Mother Nature."
Time has already removed many of the images.
"This really used to be like the Sistine Chapel," Kostrba said. "There were pictographs on the ceiling, on the wall panels and on the boulders in front."
The images were first catalogued in 1937. But even then archaeologists who turned over rocks that had fallen from the ceiling found traces of artwork.