Blue River Township, Johnson County, IndianaBlue River Township is one of nine townships in Johnson County, Indiana, United States. As of the 2010 census, its population was 4,936 and it contained 2,096 housing units.HistoryThe Furnas Mill Bridge was listed on the National Register of Historic Places in 2001.GeographyAccording to the 2010 census, the township has a total area of, of which is land and is water.