 Population growth was slow until after World War II, when roads improved and people could commute to nearby Tacoma, Fort Lewis, and Seattle.South Hill is located at (47.121080, -122.290506).According to the United States Census Bureau, the CDP has a total area of 18.1 square miles (46.8 km²), of which, 18.0 square miles (46.6 km²) of it is land and 0.1 square miles (0.2 km²) of it (0.39%) is water.