This report presents four radiocarbon dates of charcoal pigments from Picture Cave, a site located in a remote wooded area in east-central Missouri. Carbon from charcoal pigments was extracted from three rock drawings on the wall of this cave. The four pigment samples contained sufficient carbon for accelerator mass spectrometric radiocarbon analysis. These black pigment samples (red and white paints are also present in the cave) yielded dates that place their affiliated motifs in a time frame associated with Cahokia ca. 950 years ago. The dates are somewhat earlier than expected. We discuss the dates in connection with the iconography of the three motif panels tested.
The age reported for this pictograph is the first “direct” radiocarbon age determination for a pictograph in Wisconsin. The near est pictographs to Arnold/Tainter Cave that have been radiocarbon dated are those in Missouri studied by Diaz-Granados et al. (2001).
Both are from Cahokia and date to around AD 1050. Lepper et al. (2018) proposed that the iconic imagery of Serpent Mound, as depicted in the James P. MacLean map (Figure 2), invoked the same “mystery and hidden knowledge”, which it shared with contemporary pictographs on the walls of Picture Cave in Missouri (Diaz-Granados et al., 2001;Duncan et al., 2015: 125-132). Ephraim Squier and Edwin Davis’ 1848 map of Serpent Mound has been the accepted representation of the serpent for more than a century, but there are reasons for doubting its accuracy.