Data from more than 75,000 community public supply wells were acquired from national and state agencies. Using the information provided by the agencies, along with surficial and bedrock geologic maps, the wells were assigned to a national Principal Aquifer (PA) as defined in USGS (2003) or a Secondary Hydrogeologic Region (SHR) as defined in Belitz et al. (2018). Collectively, both PAs and SHRs are referred to as Hydrogeologic Regions (HRs). The HR identifies the primary source of water for the well. The locations of the wells were generalized so that they plot in the center of a 2 kilometer square grid. The county information provided identifies the county the well is located within based on it’s actual location, not the generalized location. A total of 76,354 wells were assigned to an HR, 41 wells were assigned to "basement" or "bedrock" because there was not enough information to assign to a specific HR.