ZIP code 99170 is officially located in the state of Washington, primarily serving the city of Rosalia. It falls under the administrative jurisdiction of Whitman County. When planning mail delivery, logistics routing, or demographic research, 99170 operates within the Pacific Time (PT) timezone and supports the 759 area codes.
According to the latest US Census Bureau and American Community Survey (ACS) datasets, the total population residing within the 99170 ZIP Code Tabulation Area is approximately 36,459. Understanding local economics is critical for market analysis; the median household income in this postal area sits at $130,170.