Figure 17
34RM507, West Profile #2, Section 29-13N-23W, Roger Mills County, Oklahoma. Radiocarbon dates on charcoal in this laminated canyon fill indicate rapid refilling of the canyons on the Dempsey Divide at the end of the Altithermal, from about BC 1300 to AD 100. Distinct bands of high charcoal density in the profile, presumably reflecting periods of frequent range fires, suggest periods of greater rainfall at BC 500-300 and BC 900-700. This may seem counter-intuitive, but coming out of the Altithermal, it probably took considerable increases in rainfall just to generate sufficient biomass for a fire to carry. We infer that a first relatively robust post-Altithermal pluvial around BC 1300-1100 initiated the accretion of sediment in Higgins Canyon at 34RM507. The earliest occupation at this site dates AD 30-45.