Airborne electromagnetic (AEM) and magnetic survey data were collected during November 2017 over a total distance of 1,980 line kilometers in the southwestern San Joaquin Valley of California adjacent to the Elk Hills, North and South Coles Levee, and Buena Vista oil fields. These data were collected in support of groundwater salinity mapping and hydrogeologic framework development as part of the U.S. Geological Survey California Oil, Gas, and Groundwater program and the California State Water Resources Control Board’s Oil and Gas Regional Monitoring Program. Data were acquired by SkyTEM ApS with the SkyTEM 312 time-domain helicopter-borne electromagnetic system together with a Geometrics G822A cesium vapor magnetometer. The survey was flown at a nominal flight height of 35 m above terrain along block-style lines with a nominal spacing of 300 m. The AEM typical maximum depth of investigation is between 150 and 300 m. This data release includes minimally processed (raw) AEM and raw/processed magnetic data, fully processed AEM data used for resistivity model development, and laterally constrained inverted resistivity models. The complete data package received from the contractor is included in separate zip-file directory and described in the contractor's report.