Audrain county was formed from a non-county area with portions under the administration of Montgomery, Callaway, Boone, Ralls, or Monroe counties at various times prior to its official establishment in 1836. Thus, records for locations now in Audrain prior to 1836 may indicate location in those counties instead. Some details have been summarized on the website of the Northeast Missouri Genealogy Village, and a dynamic map showing some of the changes is on the 'mapgeeks' website showing historical maps of the states of the USA. (See 'External Links' below.)