ABSTRACT Results of pollen analyses of dual sediment cores from alluvium of Caddo Creek in northern Anderson County in East Texas replicate trends of vegetation change during the last 6,700 years. These floral changes include most importantly a long-term decline of hickory and a rise of pine due to physiographic factors of irreversible soil acidification. With a view to factors of climate change, a major xeric phase is defined between 4000 and 3000 BP, when grassland vegetation expands beyond its present range. Human impacts during the prehistoric period are comparatively limited despite a regional presence of many archaeological sites, although tentative evidence for a Native sylviculture of hickory is considered. Methods of alluvial palynology pioneered in East Texas are validated through an application of strict checks on palynological data sets.