ZIP code 99138 is officially located in the state of Washington, primarily serving the city of Inchelium. It falls under the administrative jurisdiction of Ferry County. When planning mail delivery, logistics routing, or demographic research, 99138 operates within the Pacific Time (PT) timezone and supports the 207 area codes.
According to the latest US Census Bureau and American Community Survey (ACS) datasets, the total population residing within the 99138 ZIP Code Tabulation Area is approximately 16,307. Understanding local economics is critical for market analysis; the median household income in this postal area sits at $86,138.