Puget Sound Regional Council major cities are Seattle, Bellevue in King County, Tacoma in Pierce County, Everett in Snohomish County, and Bremerton in Kitsap County. The region's population was estimated to be over 3.8 million as of April 2014. In 1956 the four counties of the Puget Sound region established the Puget Sound Regional Planning Conference, which changed its name to the Puget Sound Governmental Conference (PSGC) in 1958. It launched the Puget Sound Regional Transportation Study (PSRTS) in 1962 with support from the Washington State Highway Commission, the U.S. Bureau of Public Roads (predecessor of the Federal Highway Administration), and the U.S. Department
Puget Sound faults Lowland. In particular, to the southeast of Mount St. Helens and Mount Rainier they reflect a regional pattern of NNW oriented faulting, including the Entiat Fault in the North Cascades and the Portland Hills and related faults around Portland (see QFFDB fault map). Yet the SHZ and WRZ may be integral to the regional geology of Puget Sound, possibly revealing some deep and significant facets, and may also present significant seismic hazard. The WRZ and SHZ are associated with the "southern Washington Cascades conductor" (SWCC), a formation of enhanced electrical conductivity lying roughly between Riffe Lake and Mounts St. Helens,