 According to the United States Census Bureau, the town has a total area of 11.3 square miles (29.2 km²), of which, 11.3 square miles (29.2 km²) of it is land and 0.09% is water.Nelson Township is bordered by the Town of Tuscarora in Steuben County, New York to the north, Lawrence Township to the east, Farmington Township to the south and Osceola Township and Elkland to the west.As of the census of 2000, there were 587 people, 231 households, and 176 families residing in the township.