I grew up with a geologist for a father, so many childhood road trips were out in the desert, looking at rocks. An extension of this was hunting for rock art. In general, rock art comes in two forms: petroglyphs and pictographs. Petroglyphs are pictures that are chipped into the rock using another rock. They have texture, though you shouldn’t actually touch them since the oils in your hand can damage the glyph. Pictographs are painted on to the rock, using pigments and usually an animal fat binder. The famous cave paintings from France are a prime example of pictographs.
Since I have yet to pull my camera out this summer, I thought I’d treat you to some of the rock art I’ve recorded over my life. First up is an example of Paiute workmanship, located at Petroglyph Lake on the Hart Mountain National Antelope Refuge in Eastern Oregon.
I took these photos this spring, on the mammology field trip with Hillary and Stewart. I had a wonderful time! The high steppe sagebrush desert of Eastern Oregon feels nearly like home to me, and my dad loves the place, so he came out and saved us all a campsite (very important on Memorial day weekend).
Next up are petroglyphs from Celebration Park, near Melba, Idaho. They are carved on basalt Mellon Gravel, which are essentially giant, smooth river rocks deposited from the Bonneville Flood. This rock below is about as tall as I am! Imagine the sort of water power it would taken to tumble a boulder this big.
The reason the petroglyphs stand out so clearly is due to something called desert varnish, or patina. Essentially, there are little microorganisms that poop all over the rock and, over time, this forms a sort of protective outer coating on the rock. When a petroglyph is chipped into the rock, it breaks through to the natural color of the rock below. As the petroglyph ages, it too takes on the darker patina.
This translates roughly as light = young, dark = old.
Quality petroglyphs tend to be in the desert for the same reason it takes the Basin and Range region 500 plus years to accumulate an inch of soil — there is very little water to break down stone, so things on rocks tend to stick around.
You can see below the Snake River flowing through the desert. This area was highly prized as wintering grounds for the Paiute, especially before the dams on the Snake and Columbia were put in. Local accounts record the salmon being so thick that one could walk across the river on the backs of them all.
This next picture is from Mesa Verde, Colo. The spiraling line is thought to indicate a journey. The artists for Mesa Verde, Sand Island Bluff and Newspaper Rock were all Hopi, or their cousins and ancestors.
The last group of pictures are of pictographs in Barrier Canyon, Utah. These were done by western archaic people, and show definite influences of datura trips. These pictographs were absolutely stunning in person, with figures being eight or nine feet high.
There is still no consensus on whether petroglyphs actually communicated information, or whether they were just done out of artistic endeavor. If you’re interested in finding out more information about how to interpret rock art, follow this link: http://www.rocklanguage.com/index.html. This Web site has information about a very interesting book done by an adult adoptee of a Paiute man who said his adopted father told him how to interpret the rocks. For now, the mystery behind these beautiful works of art still lives on.