A milling stone and a pestle were recovered at site LKP-2023-1, which is situated along the upper Klamath River in Siskiyou County, California. The pestle was associated with a radiocarbon date of 780 ± 30 BP. After completing analysis of these two tools, two more groundstone (a handstone and the battered end of a pestle) were submitted for pollen analysis.
Linda Scott Cummings (Mon,) studied this question.