The soils of Catoctin have been characterized in the Soil Survey of Frederick County as primarily rough, stony land. In general, they are well drained, poorly developed soils containing numerous stones and boulders throughout their profile. The soils in the eastern portion of the park are thin, sandy loams formed from the erosion of the Weverton quartzite. They are highly permeable and well-drained. The soils of the western side of the park were derived from metavolcanic rock and are deeper, moister, and contain more nutrients.
In 1998 a comprehensive soil survey was done by USDA Natural Resource Conservation Service. This survey was accomplished by digging small holes to study the soil profile, which is the sequence of natural layers, or horizons, in a soil. Soil textures, color, particle size, and other features also helped classify the soil types. Each kind of soil is associated with a particular kind of landform or with a segment of the landform. By observing soils and their relationships with the landforms the scientists were able to develop a model that would predict, with a considerable degree of accuracy, the kind of soil at a location. This method allowed nearly 5,810 acres of soils to be surveyed, classified, and mapped in a relatively short time.