ZIP code 37031 is officially located in the state of Tennessee, primarily serving the city of Castalian spring. It falls under the administrative jurisdiction of Sumner County. When planning mail delivery, logistics routing, or demographic research, 37031 operates within the Central Time (CT) timezone and supports the 729 area codes.
According to the latest US Census Bureau and American Community Survey (ACS) datasets, the total population residing within the 37031 ZIP Code Tabulation Area is approximately 23,129. Understanding local economics is critical for market analysis; the median household income in this postal area sits at $67,031.