This report includes a state-of-the-art review of seismicity, attenuation characteristics, and seismic zonation in Washington and the Pacific Northwest. Based on this information, a map of velocity-related acceleration coefficients for Washington was developed. The map is in a format suitable for use in the AASHTO highway bridge design procedure. Also, it is based on more detailed seismic and geologic data than the present AASHTO map and was developed specifically for Washington rather than the entire United States. Therefore, the map is suggested as a potential replacement for the present AASHTO map for seismic bridge design in Washington.