Potential wetlands in training areas on Ravenna Army Ammunition Plant, Ohio, were mapped by use of geographic information system (GIS) data layers and field inspection. The GIS data layers were compiled from existing sources and interpretation of aerial photography. Data layers used in the GIS analysis were wetland-plant communities, hydric soils, National Wetlands Inventory designated areas, and wet areas based on photogrammetry. According to review of these data layers, potential wetlands constitute almost one-third of the land in the training areas. A composite map of these four data layers was compiled for use during inspection of the training areas. Field inspection focused on the presence of hydrophytic vegetation and macroscopic evidences of wetland hydrology. Results of the field inspection were in general agreement with those predicted by the GIS analysis, except that some wet areas were more extensive than predicted because of high amounts of precipitation during critical periods of 1995 and 1996. Guidelines for managing wetlands in the training areas are presented.