Magnetic and electromagnetic (EM) methods are perhaps the most convenient and popular geophysical survey methods for detecting buried manmade objects, which is due to their non‐intrusiveness, light field logistics, high survey speed, and the quality of information. One should always consider the two methods as the precursor to any geophysical survey. Often, the data resulting from the two methods are sufficient for characterizing buried objects.In this paper, we present magnetic and EM data collected at four sites: (1) Cloud Chamber at the Nevada Test Site, (2) Anacostia Metro Tunnels in Washington, D.C., (3) Cold Test Pit at Idaho National Engineering Laboratory, and (4) Unexploded ordnance site at Jefferson Proving Ground, Indiana. The first two sites may be considered typical underground facilities. The last two sites, however, contain small buried objects (storage tanks, ordnance, etc.) specifically prepared to test various geophysical methods for detection and, possibly, discrimination.We find throug...