Seattle is the northernmost major city in the contiguous United States, and the largest city in the Pacific Northwest and in the state of Washington. A seaport situated on a narrow isthmus between Puget Sound (an arm of the Pacific Ocean) and Lake Washington, about 100 miles (160 km) south of the Canada – United States border, it is named after Chief Sealth "Seattle", of the Duwamish and Suquamish native tribes. Seattle is the center of the Seattle–Tacoma–Bellevue metropolitan statistical area, the 15th largest in the United States, and the largest in the northwestern United States. Seattle is the county seat of King County and is the major economic, cultural and educational center in the region. The 2010 census found that Seattle is home to 630,320 residents within a metropolitan area of some 3.4 million inhabitants. The Port of Seattle and Seattle–Tacoma International Airport are major gateways to Asia, Alaska, and the rest of the world.