Mason County, county in Illinois, United States. As of 2020 county had an estimated population of 13,173 inhabitants. The county was created 183 years ago in 1841. Its county seat is Havana.
There are 1 city/town in Mason County, IL. The largest city of Mason County is Allen with a population of 536.
Allen, Township in LaSalle County, Illinois
List of cities, towns, neighborhoods & other populated places in Mason County.
City Name | Title | Population |
---|---|---|
Allen | Township in LaSalle County, Illinois | 536 |