The U.S. Geological Survey (USGS) in cooperation with the California State Water Resources Control Board (State Water Board) compiled and analyzed data for mapping groundwater salinity, characterizing aquifer systems, and documenting the effects of oil field water injection in the Elk Hills Elk Hills, Buena Vista, and Coles Levee Oil Fields, San Joaquin Valley, California. Data provided in this data release include borehole geophysical data, geochemical analyses of water samples, hydrologic data, geological formation depths, and information on observed well log resistivity anomalies—interpreted to be from injection for disposal of produced water from oil wells or from natural causes. The data reported here were used in an accompanying interpretive manuscript describing aquifer salinity and the effects of produced water disposal in the study area. The geochemical data were compiled for water samples from 14 water source wells to supply groundwater for oil and gas operations and one groundwater monitoring well. The constituents compiled from geochemical data sources included water-quality indicators and detected concentrations of major ions, minor ions, and trace elements. The data represent several decades and most originated from oil and gas producers which are archived in scanned pages in raster format on the California Geologic Energy Management Division (CalGEM) website. The data were compiled into computer readable numerical data sets for the related study. Other data, such as interpolated surfaces of geologic layers, were created for the study based on information in drilling records and are provided here. All the data and the associated manuscript are part of the State Water Board Oil and Gas Regional Monitoring Program and the associated USGS California Oil, Gas, and Groundwater (COGG) Program.