ZIP Codes of Delaware County, OK

Population & People
Population & People
Total Population
33,376
Household Income
Household Income
Median Income
$58,257
Housing
Housing
Total Housing Units
17,919
Business & Economy
Business & Economy
Total Businesses
703
Employment
Employment
Employment Rate
46.91%
Education
Education
Bachelor's Degree+
19.54%
Source: U.S. Census ACS 2024 5-Year Estimates · rolled up across the 8 ZIPs in this county.
Data Last Updated: June 1, 2026
ZIP Codes:8 ZIP Codes (7 Standard, 1 PO Box, 0 Unique) [See All]
Area Codes:539 / 918
Timezone:Central (GMT -06:00)
Local Time:2:13:24 PM
Population:33,376 [See All]
FIPS:40041
Land Area:614 sq mi
Water Area:32 sq mi
Coordinates:36.3550, -94.7801
Quick Link:
https://www.zip-codes.com/county/ok-delaware.asp
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Wide geographic spread
ZIPs range from 228.3 sq mi down to 2.02 — a 113× sprawl ratio.
Among Oklahoma's 5 oldest counties
Median age 46.0.

Standout ZIPs in this County


Most Populous
Grove · 14,876 people
44.6% of county total
Highest Income
Grove · $58,125 median
1.0× county average
Largest Land Area
Jay · 228.3 sq mi
Spans the most ground
Fastest Growth
Jay · 6.6% (10-yr)
7,756 → 8,266 residents
Most Educated
Grove · 25.1% bachelor's+
2,872 of 11,422 adults 25+

Things worth knowing about Delaware County


33,376 residents live across 8 ZIPs covering 614 sq mi, served by 7 distinct USPS-recognized cities.

Population moved from 34,303 to 33,376 from 2014 to 2024 — a -2.7% change. 2 ZIPs gained residents, 5 lost.

The county's wealthiest ZIP 74344 (Grove, $58,125 median) and poorest ZIP 74359 (Oaks, $45,625) are 29.5 miles apart — a 1.3× income gap across local geography.

Median home values vary 3.8× across this county — from $59,000 in 74359 (Oaks) to $221,400 in 74344 (Grove).

Density varies across the county — from 27 people/sq mi in 74342 (Eucha) to 140 in 74344 (Grove).

Educational attainment ranges from 13.1% bachelor's+ in 74338 (Colcord) to 25.1% in 74344 (Grove) — the breadth of educational profiles across the area.

Within Oklahoma, this is the #29 most populous of 78 counties and ranks #44 for median household income .

Weighted by population, the typical household earns about $54,969 across the county — reflecting what a typical resident sees, not a simple ZIP average.

19.5% of adults age 25+ hold a bachelor's degree or higher (4,689 of 24,003 reporting).

7 Standard delivery, 1 PO Box only, 0 single-entity Unique ZIPs serve this county.

Stories about Delaware County


Big & sparse

A frontier county — vast land area with only a few residents per square mile. Daily life looks very different here than in the country's denser counties.

Total area
614
square miles
Avg density
54.4
people per sq mi
Population
33,376
across 8 ZIPs
Jay
228.3 sq mi
8,266 residents
Colcord
155.6 sq mi
5,069 residents
Grove
106.1 sq mi
14,876 residents

All ZIP Codes in Delaware County


ZIPCityTypePopulationMedian IncomeArea (sq mi)10-yr Growth
74344GroveStandard14,876$58,125106.12.7%
74346JayStandard8,266$49,556228.36.6%
74338ColcordStandard5,069$57,768155.6-4.4%
74347KansasStandard2,757$47,52644.1-8.1%
74342EuchaStandard2,039$57,32174.7-31.8%
74359OaksStandard309$45,6253.1-56.2%
74368Twin OaksStandard60$91,8752.0-15.5%
74345GrovePO Box0.0

Adjacent & Nearby Counties