A detailed airborne radiometric survey of Mountain Pass, California was flown by CGG Canada Services Ltd. (CGG). The high-resolution helicopter survey was flown at a flight-line spacing of 100 and 200 m, a flight-line azimuth of 70 degrees, a nominal flight-line elevation above ground of 70 m, and consists of about 1,814 line-kilometers. Tie lines were spaced at a 1-km interval with a flight-line azimuth of 160 degrees. Data were collected using a Radiation Solutions RS-500 spectrometer and processed by CGG using standard radiometric surveying techniques (e.g., International Atomic Energy Agency, 2003) that include corrections for aircraft and cosmic background radiation, radon background, Compton scattering effects, and variations in altitude. Radioelement data are presented as ASCII grids of potassium (K) in per cent, equivalent thorium (eTh) in parts per million (ppm), and equivalent uranium (eU) in ppm. Airborne radiometric maps of Mountain Pass were published by Ponce and Denton (2019).