Flagstaff is a city located in northern Arizona, in the southwestern United States. In 2013, the city's estimated population was 68,667. The combined metropolitan area of Flagstaff has an estimated population of 136,539. It is the county seat of Coconino County. The city is named after a ponderosa pine flagpole made by a scouting party from Boston (known as the "Second Boston Party") to celebrate the United States Centennial on July 4, 1876.