Puget Sound only Puget Sound proper but also for waters to the north, such as Bellingham Bay and the San Juan Islands region. The term "Puget Sound" is used not just for the body of water but also the Puget Sound region centered on the sound. Major cities on the sound include Seattle, Tacoma, Olympia, and Everett, Washington. Puget Sound is also the third largest estuary in the United States, after Chesapeake Bay in Maryland and Virginia, and San Francisco Bay in northern California. In 1792 George Vancouver gave the name "Puget's Sound" to the waters south of the Tacoma Narrows, in
Puget Sound Bay, the Dungeness and Elwha into the Strait of Juan de Fuca. The Chilliwack River flows north to the Fraser River in Canada. Tides in Puget Sound are of the mixed type with two high and two low tides each tidal day. These are called Higher High Water (HHW), Lower Low Water (LLW), Lower High Water (LHW), and Higher Low Water (HLW). The configuration of basins, sills, and interconnections cause the tidal range to increase within Puget Sound. The difference in height between the Higher High Water and the Lower Low Water averages about at Port Townsend on Admiralty Inlet,