| City: | Guasti, California |
| County: | San Bernardino County |
| Timezone: | Pacific (GMT -08:00) |
| Local Time: | 9:37:42 AM |
| Population: | No Population Data |
| Area Codes: | 840 / 909 / 951 |
| Classification: | PO Box |
| Coordinates: | 34.0663, -117.5893 |
| Quick Link: |
Guasti is a ghost of California wine history. The 91743 ZIP code covers just 0.007 square miles in San Bernardino County, essentially the footprint of a single post office. Zero residents live within its boundaries today, but the name dates back to Secondo Guasti's Italian Vineyard Company, which once operated the world's largest winery here.
The post office maintains 189 PO Boxes and serves 67 businesses despite having no residential population. This is a PO Box Only Zone, meaning there's no alternative delivery method within 91743 itself. Surrounding cities provide street delivery: Downtown Ontario sits 3.2 miles west, Fontana Gateway 3.5 miles east, and Rancho Cucamonga a few miles north.
N Turner Avenue accounts for most address records (36 of 38 total), with units suggesting commercial or industrial mail recipients. E Guasti Road preserves the founder's name. The area has transformed from vineyards to warehouses and logistics centers, but this tiny ZIP code persists as a postal artifact of California's wine country past.
N Turner Ave dominates with unit-based addressing typical of commercial properties. E Guasti Rd preserves the wine colony founder's name.
ZIP Code 91743 supports both business and residential activity. According to the Business Census (2024), there are 5 business establishments, employing about 7 people with an annual payroll of $276,000.
| # Residential Mailboxes: | 0Source: USPS |
| # Business Mailboxes: | 0Source: USPS |
| Total Delivery Receptacles: | 1,672Source: USPS |
| Single Family Delivery Units: | 0Source: USPS |
| Multi Family Delivery Units: | 0Source: USPS |
| # of Businesses: | 5Source: CBP |
| 1st Quarter Payroll: | $66,000Source: CBP |
| Annual Payroll: | $276,000Source: CBP |
| # of Employees: | 7Source: CBP |
ZIP Code 91743 is located in San Bernardino County, California, within the Riverside-San Bernardino-Ontario, CA Metropolitan Statistical Area (CBSA 40140) and California's 35th Congressional District. This Metro area has a population of 4,224,851 people, about 0.00% of whom live in ZIP Code 91743. It covers 0 sq mi of land and a water area of 0 sq mi.
| CBSA Name: | Riverside-San Bernardino-Ontario, CASource: Census |
| CBSA Number: | 40140Source: Census |
| CBSA Type: | MetroSource: Census |
| CBSA Division: | --Source: Census |
| CBSA Population: | 4,224,851Source: Census |
| MSA: | Los Angeles-Riverside-Orange County, CASource: Census |
| Land Area: | --Source: Census |
| Water Area: | --Source: Census |
| Congressional District: | 35Source: USPS |
| Congressional Land Area: | 168.88 sq miSource: Census |
| PMSA: | Riverside-San Bernardino, 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 91743 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 February 1, 2026.