 According to the United States Census Bureau, the township has a total area of 20.6 square miles (53.3 km²), of which, 20.5 square miles (53.2 km²) of it is land and 0.04 square miles (0.1 km²) of it (0.19%) is water.Limestone Township is bordered by West Buffalo Township, Mifflinburg and Buffalo Township to the north, Union Township to the east, Snyder County to the south and Lewis Township to the west.As of the census of 2000, there were 1,572 people, 526 households, and 444 families residing in the township.