Abstract
For this research I examine 123 Native American baskets from northern and central California to identify their origin by using microscopy to identify taxonomic types of certain weaving attributes. The results were categorized in tables and then displayed geographically on maps. The purpose was to see whether the visual assessment of the data agreed with past statistical studies that had concluded that cultural transmission of craft traditions were most alike between neighboring groups regardless of ethnic affilliation, and whether the data mapped geographically could add to the discussion regarding the expansion of Penutian Wintun tribes from southern Oregon into northern California. The findings agreed with the two previous statistical studies but showed that there are other factors that influence the cultural transmission of basketry traditions. The mapping of basketry attributes did not result in conclusive results, however was consistent with one generally accepted theory of the Penutian expansion.