The magnetic method measures disturbances or magnetic anomalies in the earth’s naturally occurring magnetic field, which are caused by the presence of buried or surface ferrous materials, such as steel or iron objects. These anomalies are measurable with a variety of instruments, including proton-precession and cesium vapor magnetometers. Data are recorded in the field using a digital data logger, and are downloaded to a portable computer for immediate mapping of the recorded data. The recorded anomaly locations can be compared to data recorded by other methods, such as electromagnetics, to check the possible locations of metal objects. The locations can then be marked in the field for further direct evaluations.