ZIP Codes of Harmon County, OK

Population & People
Population & People
Total Population
2,390
Household Income
Household Income
Median Income
$39,018
Housing
Housing
Total Housing Units
1,334
Business & Economy
Business & Economy
Total Businesses
50
Employment
Employment
Employment Rate
48.88%
Education
Education
Bachelor's Degree+
12.65%
Source: U.S. Census ACS 2024 5-Year Estimates · rolled up across the 3 ZIPs in this county.
Data Last Updated: June 1, 2026
ZIP Codes:3 ZIP Codes (3 Standard, 0 PO Box, 0 Unique) [See All]
Area Code:580
Timezone:Central (GMT -06:00)
Local Time:2:13:24 PM
Population:2,390 [See All]
FIPS:40057
Land Area:432 sq mi
Water Area:1 sq mi
Coordinates:34.7598, -99.8499
Quick Link:
https://www.zip-codes.com/county/ok-harmon.asp
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Notable population decline
Lost 16.0% of residents since 2014.

Standout ZIPs in this County


Most Populous
Hollis · 2,179 people
91.2% of county total
Highest Income
Hollis · $43,804 median
1.1× county average
Largest Land Area
Hollis · 232.9 sq mi
Spans the most ground
Fastest Growth
Hollis · -9.4% (10-yr)
2,405 → 2,179 residents
Most Educated
Hollis · 12.2% bachelor's+
177 of 1,451 adults 25+

Things worth knowing about Harmon County


2,390 residents live across 3 ZIPs covering 432 sq mi, served by 3 distinct USPS-recognized cities.

Population moved from 2,845 to 2,390 from 2014 to 2024 — a -16.0% change. 0 ZIPs gained residents, 3 lost.

The county's wealthiest ZIP 73550 (Hollis, $43,804 median) and poorest ZIP 73544 (Gould, $36,250) are 8.1 miles apart — a 1.2× income gap across local geography.

Median home values vary 1.2× across this county — from $64,300 in 73544 (Gould) to $80,200 in 73550 (Hollis).

Density varies across the county — from 2 people/sq mi in 73544 (Gould) to 9 in 73550 (Hollis).

Educational attainment ranges from 12.2% bachelor's+ in 73550 (Hollis) to 19.7% in 73544 (Gould) — the breadth of educational profiles across the area.

Within Oklahoma, this is the #77 most populous of 78 counties and ranks #78 for median household income .

Weighted by population, the typical household earns about $43,147 across the county — reflecting what a typical resident sees, not a simple ZIP average.

12.7% of adults age 25+ hold a bachelor's degree or higher (207 of 1,636 reporting).

3 Standard delivery, 0 PO Box only, 0 single-entity Unique ZIPs serve this county.

Stories about Harmon County


Single-ZIP anchor

One ZIP holds the majority of this county's population — a sign of a county built around a single city or town.

Hollis

Population decline

Harmon County lost 16.0% of residents between 2014 and 2024.

All ZIP Codes in Harmon County


ZIPCityTypePopulationMedian IncomeArea (sq mi)10-yr Growth
73550HollisStandard2,179$43,804232.9-9.4%
73544GouldStandard178$36,25096.5-32.1%
73571VinsonStandard33$37,000103.1-81.5%

Adjacent & Nearby Counties