St. Charles (; Spanish: "San Carlos") is a city in St. Charles County, Missouri. In 2010 there were 65,794 people living in the city. St. Charles is the second largest city, and the county seat of St. Charles County. It is northwest of St. Louis, Missouri on the Missouri River. It is the third oldest city west of the Mississippi. It began in 1765 as "Les Petites Côtes", "The Little Hills", named by Louis Blanchette, a French Canadian fur trader. The town was the starting point for the Lewis and Clark Expedition in 1804. The city served as the first Missouri capital from 1821 to 1826. The Saint Rose Philippine Duchesne shrine is in Saint Charles. It is also the home of the St. Louis National Weather Service Forecast Office, serving central, east-central and northeastern Missouri, as well as west-central and southwest Illinois.