The Marlboro Clay formation is a late Paleocene/early Eocene geologic formation that outcrops in significant portions of Prince Georges County, MD. Due to rapid urbanization, the Marlboro Clay formation is of great importance because it is unstable for most building structures due to slow permeability and possibly high shrink-swell characteristics. Water well logs are collected prior to residential and commercial development to determine ground water quantity. When drilling is taking place, the types of sediments observed are recorded as depth increases. The Marlboro Clay is easily recognized in the logs lithology description due its pink color. The large number of water well logs available with Marlboro Clay present made it possible to utilize them for performing geospatial analysis. The objectives of this project were to provide data on the morphology and problematic characteristics of soils formed from Marlboro Clay residuum and evaluate the effects of location measurement error using water well log data to map Marlboro Clay using various mapping methods. According to the samples analyzed for x-ray diffraction, we found that the Marlboro Clay was smectite and kaolinite dominated. Surficial pedogenically affected Marlboro Clay samples had moderate potential volume change ratings. The particle size of the Marlboro Clay formation varied due to varying amounts of sand from overlying and underlying Nanjemoy and Aquia formations. Some of the water well logs had very large location measurement error. Additionally, at random locations the Marlboro Clay exhibited a greater thickness in some areas than once reported, making it difficult to develop a county-wide thickness map with a high degree of certainty. The bottom elevation was smoother than the thickness and therefore we were able to develop a bottom elevation map with greater confidence.