The application of charcoal to soils to increase carbon stocks has been of great interest recently. To gain a better understanding of the long-term effects of charcoal presence in soils, historic charcoal production sites at Catoctin Mountain Park, Maryland were studied for organic carbon content and compared to nearby unaffected soils. Soil organic carbon concentrations were measured through loss on ignition, and organic carbon stocks were calculated for fixed depths of 80 cm. Both the organic carbon concentrations and organic carbon stocks indicate that historically affected charcoal hearth soils contain more carbon compared to unaffected controlled soil samples. However, there is some variation in organic carbon content between charcoal hearths located in different landscape positions. Overall, charcoal application to soils may increase organic carbon stocks for extended periods of time, which can be of great importance for climate change mitigation and the enhancement of soil fertility.