 The Gross Covered Bridge was added to the National Register of Historic Places in 1977.According to the United States Census Bureau, the township has a total area of 37.0 square miles (95.8 km²), of which, 37.0 square miles (95.7 km²) of it is land and 0.1 square miles (0.2 km²) of it (0.16%) is water.Spring Township is bordered by Union County to the north, Adams and Beaver Townships to the east, West Perry Township to the south and West Beaver Township to the west.