| City: | Mount Wilson, California |
| County: | Los Angeles County |
| Timezone: | Pacific (GMT -08:00) |
| Local Time: | 9:35:17 AM |
| Population: | No Population Data |
| Area Code: | 626 |
| Classification: | PO Box |
| Coordinates: | 34.2267, -118.0655 |
| Quick Link: |
Mount Wilson occupies 4.46 square miles in the San Gabriel Mountains of Los Angeles County, California. This ZIP serves a small mountain community at approximately 5,700 feet elevation, home to the historic Mount Wilson Observatory. With zero recorded population in Census data, this ZIP functions primarily as a service designation for a specialized location rather than a residential community.
Mail delivery follows a rural carrier route serving Video Road, the only street in this ZIP. The 12 delivery records indicate units rather than traditional street addresses, suggesting institutional or facility-based delivery. The post office maintains no PO Boxes here. This isn't a PO Box Only Zone, and nearby communities like Arcadia (3.1 miles away) and Pasadena (3.4 miles) provide standard postal services for the broader region.
Mount Wilson's postal designation supports the observatory complex and related scientific facilities. The location has been a center for astronomical research since 1904, when the Mount Wilson Observatory was established. Video Road likely serves the broadcast transmission facilities that share the mountain peak with the observatory.
Single street with unit-based delivery suggests institutional or broadcast facility service.
ZIP Code 91023 is designated for PO Box delivery only; business establishment and employment data are not available. USPS data shows 10 residential mailboxes and 0 business mailboxes, reflecting local delivery coverage.
| # Residential Mailboxes: | 10Source: USPS |
| # Business Mailboxes: | 0Source: USPS |
| Total Delivery Receptacles: | 10Source: USPS |
| Single Family Delivery Units: | 0Source: USPS |
| Multi Family Delivery Units: | 10Source: USPS |
| # of Businesses: | 0Source: CBP |
| 1st Quarter Payroll: | $0Source: CBP |
| Annual Payroll: | $0Source: CBP |
| # of Employees: | 0Source: CBP |
ZIP Code 91023 is located in Los Angeles County, California, within the Los Angeles-Long Beach-Anaheim, CA Metropolitan Statistical Area (CBSA 31080) and California's 28th Congressional District. This Metro area has a population of 0 people, about 0.00% of whom live in ZIP Code 91023, and is subdivided into the Los Angeles-Long Beach-Glendale, CA division. It covers 0 sq mi of land and a water area of 0 sq mi.
| CBSA Name: | Los Angeles-Long Beach-Anaheim, CASource: Census |
| CBSA Number: | 31080Source: Census |
| CBSA Type: | MetroSource: Census |
| CBSA Division: | Los Angeles-Long Beach-Glendale, CA (CBSA Div 31084)Source: Census |
| CBSA Population: | 0Source: Census |
| MSA: | Los Angeles-Riverside-Orange County, CASource: Census |
| Land Area: | --Source: Census |
| Water Area: | --Source: Census |
| Congressional District: | 28Source: USPS |
| Congressional Land Area: | 218.45 sq miSource: Census |
| PMSA: | Los Angeles-Long Beach, CA PMSASource: Census |
| Intro Date: | < 2004-10Source: ZIP-Codes.com |
| Place FIPS Code: | --Source: Census |
| Place Name: | --Source: Census |
We could not locate which school district 91023 belongs to, but we will update this once new district data is released. There are no public schools nor private schools with a mailing address in this ZIP Code. Listing Nearby schools instead. It also has 6 colleges, universities or post secondary education institutions nearby which would be a short commute to.
Our sources include trusted federal and licensed data from the United States Postal Service, U.S. Census Bureau, U.S. Geological Survey, Centers for Medicare & Medicaid Services, and the National Center for Education Statistics, along with proprietary datasets created by ZIP-Codes.com. Data last updated on March 1, 2026.