The mapping and interpretation of magnetic anomalies provide a useful and efficient method of studying crystalline basement rocks, igneous intrusions, and extrusive rocks of the continental crust. Accordingly, government, academic, and industrial efforts have been expended during the past four years in acquiring and interpreting new data, re‐interpreting old data, and developing new techniques for the analysis of magnetic anomaly data. Magnetic anomaly interpretation continues to be a major element in mineral exploration geophysics and a small but significant part of petroleum exploration. During the past several years these techniques have assumed increasing significance in basic geologic studies, geothermal investigations, and engineering studies related to seismic regionalization and site stability problems.