 Lucas Township was organized in 1873.According to the United States Census Bureau, the township has a total area of 35.7 square miles (92.3 km²), of which 33.8 square miles (87.5 km²) of it is land and 1.9 square miles (4.8 km²) of it (5.19%) is water.As of the census of 2000, there were 260 people, 85 households, and 70 families residing in the township.