County ZIP codes · Oklahoma · FIPS 40057
Harmon County, OK ZIP Codes
Harmon County, Oklahoma has 6 ZIP codes (Census 2020 ZCTA-county file; GeoNames postal codes, October 2026), all residential. 3 of the residential ones lie mainly in Harmon County and 3 mainly in a neighboring county; 3 cross the county line.
- ACS2020-24
- Census2020
Where are the ZIP codes of Harmon County?
Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries; ACS 2020-2024 5-year estimates (B19013).
All 6 residential ZIP codes in Harmon County
3 ZIP codes lie mainly in Harmon County; 3 more reach into it from a neighboring county and follow the first table.
| In this county | ||||||
|---|---|---|---|---|---|---|
| 73550 | Hollis | 2,179 | 9 | $44k | $80k | 100% |
| 73544 | Gould | 178 | 2 | $36k | $64k | 100% |
| 73571 | Vinson | 33 | 0 | $37k | $161k | 100% |
Partly in Harmon County
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates; county shares by land area (Census 2020 ZCTA-county relationship file).
Which ZIP codes cross the county line?
3 ZIP codes of Harmon County extend into another county. A ZIP code follows mail routes, not county borders.
| ZIP | In Harmon | Elsewhere |
|---|---|---|
| 73554 | 13% | Greer County86%; Jackson County1% |
| 73537 | 20% | Jackson County80% |
| 73532 | 12% | Jackson County88% |
Source: U.S. Census Bureau, 2020 ZCTA-county relationship file (shares of land area).
Which first three digits do Harmon County's ZIP codes use?
The first three digits of a ZIP code name the sectional center, the mail processing plant that sorts it. Every ZIP code of Harmon County starts with 735.
| Prefix | Sectional center | Here | All codes |
|---|---|---|---|
| 735 | Oklahoma City, OK (SCF 730) | 6 | 55 |
Source: U.S. Postal Service, labeling list L005 (3-digit ZIP Code prefix groups, SCF sortation), effective October 1, 2026.