There were numerous conferences within the IHSAA that were made up of schools based entirely in one county. Many of these "County Conferences" also contained schools from neighboring counties that were either geographically closer or smaller than the other schools in their home county. These conferences would fold when schools would consolidate and seek out other, more expansive conferences that included similar-sized schools. The starting date of many of these conferences is hard to confirm, so the listing for many of these leagues uses the earliest date that can be confirmed.