Rock Grove Township is located in Stephenson County, Illinois. As of the 2010 census, its population was 1,388 and it contained 761 housing units.[3] The unincorporated community of Rock Grove is located in the township, and once Duncannon was located here also.
Geography
Rock Grove is Township 28 (part) and 29 North, Range 8 (part) and 9 East of the Fourth Principal Meridian.
According to the 2010 census, the township has a total area of 30.42 square miles (78.8 km2), of which 30.27 square miles (78.4 km2) (or 99.51%) is land and 0.15 square miles (0.39 km2) (or 0.49%) is water.[3]