ZIP code 61101 is officially located in the state of Illinois, primarily serving the city of Rockford. It falls under the administrative jurisdiction of Winnebago County. When planning mail delivery, logistics routing, or demographic research, 61101 operates within the Central Time (CT) timezone and supports the 640 area codes.
According to the latest US Census Bureau and American Community Survey (ACS) datasets, the total population residing within the 61101 ZIP Code Tabulation Area is approximately 20,240. Understanding local economics is critical for market analysis; the median household income in this postal area sits at $57,101.