The Ohio Department of Natural Resources (ODNR), Division of Geological Survey (Ohio Geological Survey) performed an estimation of the remaining and available coal resources of the Lower Freeport (No. 6a) coal bed in Ohio. This study represents the first statewide estimation of Lower Freeport coal resources in 55 years. Data points were collected to create base-elevation structure and isopach maps using Geographic Information Systems (GIS) technology. The base-elevation structure map was constructed from 7,190 data points using the Natural Neighbor interpolation technique. Sequential Gaussian simulation was used to create isopach maps from 3,277 data points, which were then summarized by county to obtain coal tonnages. Project results reveal that the Lower Freeport coal bed had an estimated 6.2 billion short tons of coal in Ohio before mining. Of that amount, 400 million short tons have been mined and approximately 5.8 billion tons remain. Of the remaining resources, 41 million short tons are available for surface mining, and 2.2 billion short tons are available for underground mining. The majority of the available resources exist in Harrison County (638 million short tons) and Jefferson County (625 million short tons). Given that the current rate of mining for the Lower Freeport is approximately 700,000 short tons per year, these resources will last for more than a century.