| Boone County Illinois Cities/Towns - Belvidere (County Seat), Caledonia, Capron, Loves Park, Poplar Grove, Timberlane |
![]() |
Your Ad Here Boone County is a county located in the U.S. state of Illinois. As of the 2000 census, the population was 41,786. Its county seat is Belvidere, Illinois. History Boone County was formed in 1837. It was named for Kentucky frontiersman Daniel Boone. ![]() |