Mudhen 5k Trail Run at Big Marsh

Chicago is the most populous city in the U.S. state of Illinois and in the Midwestern United States. Located on the western shore of Lake Michigan, it is the third-most populous city in the United States and the fifth-most populous city in North America, with a population of 2.74 million at the 2020 census. The Chicago metropolitan area has approximately 9.62 million residents according to the 2020 census and is the third-largest metropolitan statistical area in the country and part of the fourth-largest combined statistical area in the United States, spanning 19 counties in three states and with a population of nearly 10 million. Chicago is the county seat of Cook County, the second-most populous county in the U.S.