Portland Township is located in Whiteside County, Illinois. As of the 2010 census, its population was 422 and it contained 186 housing units. Geography According to the 2010 census, the township has a total area of , of which (or 97.42%) is land and (or 2.58%) is water. Demographics References External links City-data.com Whiteside County Official Site Townships in Whiteside County, Illinois Townships in Illinois