North Fork Township, Delaware County, Iowa  North Fork Township is a township in Delaware County, Iowa, USA. As of the 2000 census, its population was 512. North Fork Township covers an area of 36.3 square miles (94.02 square kilometers); of this, 0.05 square miles (0.13 square kilometers) or 0.14 percent is water. The streams of Cooksley Creek, Durion Creek, Penn Creek and Silver Creek run through this township. (This list is based on USGS data and may include former settlements.) The township contains one cemetery, Rockville.