Mankato is a city in Blue Earth, Nicollet, and Le Sueur counties in the state of Minnesota. It is Minnesota's 22nd biggest city. The population was 41,044 according to 2015 US census estimates, making it the fifth largest city in Minnesota outside the Minneapolis–Saint Paul metropolitan area. The county seat of Blue Earth County, it is located along a large bend of the Minnesota River at its confluence with the Blue Earth River. Mankato is across the Minnesota River from North Mankato. Mankato and North Mankato have a combined population of over 53,000, according to the 2010 census. It completely encompasses the town of Skyline. North of Mankato Regional Airport, a tiny non-contiguous part of the city lies within Le Sueur County. Most of the city is in Blue Earth County.Mankato is the larger of the two principal cities of the Mankato-North Mankato metropolitan area, which covers Blue Earth and Nicollet counties and had a combined population of 94,149 at the 2010 census.