Poutwater Pond Bog is a National Natural Landmark located in Holden, MA. As present-day species inhabiting this bog have been described, this study presents an insight into earlier inhabitants of the area during the mid- to late Holocene. A 5-m coring of peat was collected 10 m from the pond edge. Radiocarbon analysis of 10 sections of the core shows a nearly linear accumulation rate of peatland from 8500 years ago to the present. The presence of mineral matter at the base of the core suggests paulidification as the mechanism for formation of the bog. Microfossils were isolated from sections of the peat core by density-buoyant centrifugation, and examined using a scanning electron microscope. High-resolution images of pollen, sponge remains, and algae are presented. Circumneutral and acidobiontic diatoms were found at different depths of the core, indicating a changing water environment over time. Arboreal pollen grains were documented spanning 8500 years of vegetative history, permitting insight into the biodiversity that once existed.