The goal of this project is to evaluate the ability of modern seismic methods to detect, map and analyze naturally fractured gas reservoirs, and assess future research needs in this area. During the last ten years there has been considerable research in developing and evaluating various seismic techniques for fracture characterization for petroleum and gas applications as well as for mining, geothermal and nuclear waste disposal. Current methods rely on gross definition of fracture properties using attributes such as P-wave anisotropy, AVO (Amplitude versus Offset) or AVA (Amplitude versus Angle). While useful for gross fracture detection, these approaches have not been able to define the specific fracture sets that control permeability. This effort investigated high-resolution seismic methods (including vertical seismic profiling [VSP] and single well seismic) for their ability to provide useful information on fracture properties. A key focus of this effort was to combine the surface seismic information with current borehole seismic methods. Field studies in the San Juan Basin in New Mexico were conducted to validate the most promising seismic characterization methods, and a validation well was drilled. The final stages of the work were to synthesize project data and information to produce a handbook of the best methods for fracture characterization using seismic and well data in the San Juan Basin.