sentences:  U.S. Route 167 cuts across the southeast corner of the city limits, leading north to US 79 and Fordyce and south to Hampton, the Calhoun County seat.According to the United States Census Bureau, Thornton has a total area of , of which , or 0.84%, is water.As of the census of 2000, there were 517 people, 206 households, and 142 families residing in the city.