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 melting retreat of the Vashon Glaciation eroded the land, creating a drumlin field of hundreds of aligned drumlin hills. Lake Washington and Lake Sammamish (which are ribbon lakes), Hood Canal, and the main Puget Sound basin were altered by glacial forces. These glacial forces are not specifically "carving", as in cutting into the landscape via the mechanics of ice/glaciers, but rather eroding the landscape from melt water of the Vashon Glacier creating the drumlin field. As the ice retreated, vast amounts of glacial till were deposited throughout the Puget Sound region. The soils of the region, less than ten thousand