Although geophysical techniques have been used for investigating the geologic and hydrologic characteristics of the Earth's crust for many years, until recently they have seen limited application in the exploration of Mars. However, with the recent flights of the Gamma-Ray Spectrometer on Mars Odyssey, the MARSIS and SHARAD radar sounding instruments on Mars Express and the Mars Reconnaissance Orbiter, and the selection of the WISDOM GPR for the 2011 ExoMars rover, geophysical techniques have now been identified as the most effective approach for understanding the subsurface stratigraphy, structure, composition, physical properties, and potential distribution and state of H2O on Mars. The latter has become an especially high priority objective of the Mars Exploration Program, providing potentially important insights into the geologic and hydrologic evolution of the planet, the occurrence of past and present habitable environments, and the availability of a critical in-situ resource for supporting future human exploration. This session explores the application of electromagnetic, seismic and other types of geophysical techniques to investigations of the subsurface properties of well-characterized terrestrial desert, volcanic and cold-climate analogs of Mars. The topics addressed will include: (1) studies of the stratigraphic, structural, compositional, and hydrologic characteristics of these analog sites over the range of radar frequencies likely to be employed by present and future spacecraft investigations of Mars (~1 MHz - 3 GHz) especially in the lower range (~1 - 25 MHz), where the first-order characteristics of the Earth's crust are largely unexplored; (2) the potential diagnostic and interpretive synergies that can be realized from the application of multiple geophysical techniques (including both and electromagnetic); (3) related laboratory and geophysical modeling investigations; and (4) assessments of the real-world capabilities and limitations of spacecraft instrument prototypes in the field. Specific examples of recent investigations conducted in arid and hyper-arid volcanic environments in the western US and West Egyptian Desert will be discussed.