 Edwards County is subdivided into "Road Districts", rather than "Townships" as in most Illinois counties.Pursuant to the Land Ordinance of 1785, the Northwest Territory (including Illinois) was surveyed and mostly organized into townships that are six miles square; but Edwards County was settled prior to that survey, and its pre-existing Road Districts do not generally correspond with the survey's townships.According to the U.S. Census Bureau, the county has a total area of , of which is land and (0.1%) is water.