The Dewhurst Group is a global geophysical exploration company that specializes exclusively on site selection for geothermal exploration and geothermal power development. The Dewhurst Group consists of a team of geologists, engineers, and geophysicists that integrate geophysics, geologic mapping, and geochemistry to pinpoint geothermal sources for electric power generation. The group relies heavily on both broadband magnetotelluric (BMT) and low frequency magnetotelluric (LMT) instrumentation. MT instruments are designed and built in collaboration with the Russian Academy of Sciences and Vega Geophysics. Typically, the instruments are capable of acquiring resistivity values from a few meters in depth to many kilometers. With the LMT equipment it is often possible to gather data at depths as far down as the Mohorovicic discontinuity, the boundary between the Earth’s crust and mantle. Information at such depths can be helpful in understanding the tectonics that might drive a shallower geothermal source and related “plumbing” system.