ZIP code 91901 is officially located in the state of California, primarily serving the city of Alpine. It falls under the administrative jurisdiction of San Diego County. When planning mail delivery, logistics routing, or demographic research, 91901 operates within the Pacific Time (PT) timezone and supports the 740 area codes.
According to the latest US Census Bureau and American Community Survey (ACS) datasets, the total population residing within the 91901 ZIP Code Tabulation Area is approximately 33,640. Understanding local economics is critical for market analysis; the median household income in this postal area sits at $57,901.