The Seattle metropolitan area is located in the U.S. state of Washington and includes the city of Seattle, King County, Snohomish County, and Pierce County within the Puget Sound region. The United States Census Bureau officially defines the metropolitan area as the Seattle–Tacoma–Bellevue, WA Metropolitan Statistical Area, with an estimated population of 3,500,026, which is more than half of Washington's population as of 2012[update], making it the 15th largest Metropolitan Statistical Area in the United States.
Puget Sound // is a sound in the U.S. state of Washington, an inlet of the Pacific Ocean, and part of the Salish Sea. It is a complex estuarine system of interconnected marine waterways and basins, with one major and one minor connection to the Strait of Juan de Fuca and the open Pacific Ocean — Admiralty Inlet being the major connection and Deception Pass being the minor. Flow through Deception Pass accounts for about 2% of the total tidal exchange between Puget Sound and the Strait of Juan de Fuca. Puget Sound extends approximately 100 miles (160 km) from Deception Pass in the north to Olympia, Washington in the south. Its average depth is 205 feet (62 m) and its maximum depth, off Point Jefferson between Indianola and Kingston, is 930 feet (280 m). The depth of the main basin, between the southern tip of Whidbey Island and Tacoma, Washington, is approximately 600 feet (180 m).