Marathon County is a county located in the U.S. state of Wisconsin. As of the 2010 census, the population was 134,063. Its county seat is Wausau. It was founded in 1850, created from a portion of Portage County. At that time the county stretched to the northern border with the upper Michigan peninsula. It is named after the battlefield at Marathon, Greece.Marathon County comprises the Wausau, WI Metropolitan Statistical Area and is included in the Wausau-Stevens Point-Wisconsin Rapids, WI Combined Statistical Area.GeographyAccording to the U.S. Census Bureau, the county has a total area of, of which is land and (2.0%) is water. It is the largest county in Wisconsin by land area and fourth-largest by total area. It is also notable for containing the 45°N, 90°W point.Major highwaysAirports KAUW - Wausau Downtown Airport KCWA - Central Wisconsin AirportAdjacent countiesLincoln County - northLanglade County - northeastShawano County - eastWaupaca County - southeastPortage County - southWood County - southClark County - westTaylor County - northwest
