Mind boggling, the truths archeologists can tease out of an ancient glob.
First inhabitants of Seminole Canyon in Texas used bulbs from a yucca-like plant called sotol to cook up portable, storable cakes. Raw sotol bulbs are soapy and painfully gut cleansing. Those problems were overcome by covering them with prickly pear leaves and hot coals to bake, letting them sit for a time before grinding them into meal, adding water and forming them into cakes to be seared on a hot rock. This painstaking process produced a cake with a dirt/yam fusion flavor.
Obviously food options were scarce in the west Texas desert. The cakes were life and death valuable to those nomadic hunter gatherers with no crops, herds, flocks, or cellars to see them through hard times. So using sotol to make paint for rock art was a major sacrifice.
Paint colors came from finely ground rock. That powder, lasted better when mixed with ground deer hoof to become oil based, and only the addition of soapy sotol made that possible.
So these starving artists put in endless trial and error effort and sacrifice before they even got to the hard part: creating a work of art, an enduring message. What made the message so motivating? Maybe an appeasement to the gods? An ad for sotol cakes? Or was the message itself another painstaking construction, a means to fame or immortality through “writing”?
If so, I hope those artists know how wildly successful the effort has been. Thousands of years later so many people hunger to see the paintings that the state park built around them offers daily tours, a visitors’ center, videos. Learned people study the figures and submit papers for others to study. When the paint fades completely we’ll still be able to ponder copies and reproductions. Maybe it’s best if the meaning is never uncovered. Imagine how those learned ones will feel if the message turns out to be something like “Kilroy was here.”