This USGS site contains information on the geology units, topography, and precipitation rates of the Black Hills as it relates to the hydrology. Included is a map defining the study area, precipitation graphs, a stratigraphic column, a map denoting the distribution of hydrogeologic units, a geologic cross section, and a photo of the hydrogeologic setting. Links to an introduction to this study, objectives, products, references, and digital map services are also available through this site.
