This publication provides digital flight line data for a high-resolution horizontal magnetic gradient and radiometric survey over the Ironton, Missouri area of southeast Missouri. Data were collected using a fixed wing aircraft with magnetometers mounted in the tail stinger and each wing tip pod and a fully calibrated gamma ray spectrometer. The survey operated out of the Farmington, Missouri airport during January to mid-February of 2016. The survey covers an irregularly shaped region within a 54 x 53 square-kilometer area centered on the town of Ironton, Missouri. Data were collected along north-south flight lines spaced 300 meters (m) apart with east-west tie lines flown every 3000 m. A mean terrain clearance of 140 m was maintained except where safety dictated a higher elevation. A total of 10,253 line kilometers (km) of data were collected. Three files are available in this publication and include flight line data for the magnetic gradient survey, flight line data for the radiometric survey and a report describing the survey parameters, field operations, quality control and data reduction procedures. In addition, there are two data directories that describe the attributes in the flight line data files.