Sandia Laboratories, as part of a DOE funded investigation of underground coal gasification potential for the state of Washington, has been conducting a geophysical mapping and corehole drilling program near Centralia, Washington. The objectives of the program are to establish the continuity and quality of the coal seam and the hydrology and structure (faults) of the area as these are critical to the potential success of a gasification program. Geophysical measurements, including seismic (refraction) and electrical-electromagnetic (DC resistivity, VLF and Turam), have successfully located anomalous features indicating the presence of several faults in the site area. Follow-up corehole drilling, geophysical logging, and seismic seam wave tests verified displacements of the objective coal seam. Plans call for additional surveys, particularly seismic reflection, to precisely describe the magnitude and orientation of these displacements to enable efficient design of a gasification program.