Geophysical prospection methods have been used for decades as an aid to archaeology. Much of this work has focused on defining boundaries of known sites, helping to guide ongoing excavations, and especially imaging large architectural targets. In contrast, this talk focuses on detecting very small geophysical targets, many of which would never likely be found without geophysical methods. We will first focus on magnetic detection of small, discrete campfires in Alaska, with examples spanning 12,000 years. Implications of hearth detection will be considered in the context of broader debates about the peopling of N. America. We will then turn our attention to White Sands, New Mexico, where recent geophysical work with magnetometry and ground-penetrating radar has successfully detected thousands of Pleistocene “ghost tracks”. These footprints, many of which are invisible to the eye, record the interactions of humans and megafauna at the close of the last Ice Age. Recently collected examples of human, mammoth, and ground sloth prints will be presented. Together, these examples show instances where geophysical imaging takes on a more indispensable role in archaeological research by allowing access to untapped archaeological and iconological archives that have eluded conventional detection methods.