is a mid-sized city located on both banks of the Rock River in far northern Illinois. Rockford is often referred to as "The Forest City" and is the county seat of Winnebago County, Illinois, USA. As reported in the 2000 U.S. census, the city was home to 155,115 people, while in the 2006 estimate, it is said to have a population of 156,596, making it the third largest city in Illinois after Chicago and Aurora. The metropolitan area has 339,178 residents as of the 2000 census. During the latter part of the 20th century Rockford was the second largest city in Illinois. The current mayor is Lawrence J. Morrissey, an independent elected to a second four year term in April .
Rockford is located at (42.269770, -89.069754). According to the United States Census Bureau, the city has a total area of 56.7 square miles (146.9 km²), of which, 56.0 square miles (145.1 km²) of it is land and 0.7 square miles (1.8 km²) of it is water. Neighboring communities that border Rockford, and are considered an integral part of the Rockford metro area, are Loves Park, Machesney Park, Belvidere, and the villages of Winnebago, Roscoe, Rockton, and Cherry Valley. The Rock River is the traditional center of the Rockford area and is its most recognizable natural feature.