Prior Lake is a city 20 miles (32 km) southwest of downtown Minneapolis in the U.S. state of Minnesota in Scott County. Surrounding the shores of Lower and Upper Prior Lake, the city lies south of the Minnesota River in an area known as South of the River and establishes the urban fringe of the south-southwest portion of Minneapolis-St. Paul, the sixteenth largest metropolitan area in the United States. The U.S. Census Bureau recorded the population of the city of Prior Lake at 15,917 people at the 2000 census. Seen as the sister city of Shakopee, Prior Lake was incorporated as a village in 1851, Prior Lake is one of the oldest southern metro cities to have been absorbed by suburban growth. Along with Shakopee, the city is also experiencing reclamation to native habitat via land purchases by the Shakopee-Mdewakanton Indian Reservation, where Mystic Lake Casino and Little Six Casino are located. The city's modern growth is attributed to the completion and upgrade of State Highway 13.