Duluth is a seaport city in the U.S. state of Minnesota and the county seat of Saint Louis County. Duluth has a population of 86,238 and is the second-largest city on Lake Superior's shores, after Thunder Bay, Ontario, on the lake's Canadian border; it does, however, have the largest metropolitan area on the lake. The Duluth MSA had a population of 279,771 in 2010, the second-largest in Minnesota. The combined urban population of Duluth and its adjacent communitiesincluding Proctor, Hermantown, and Superior, Wisconsintotals over 131,000, based on 2010 census figures.