County outline
Where Greer County is located
Area breakdown
Land accounts for 99.3% of Greer County’s measured area and water for 0.7%. Its combined area converts to 1,666.9 square kilometers or approximately 411,897 acres.
Green: land · blue: water
| Measurement | Square miles | Square kilometers | Acres |
|---|---|---|---|
| Land | 639.285 | 1,655.741 | 409,142.4 |
| Water | 4.304 | 11.147 | 2,754.6 |
| Total | 643.589 | 1,666.888 | 411,897 |
How Greer County compares
By original Census land area, Greer County ranks #58 of 77 in Oklahoma and #1486 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.
Its land area is 0.796 times the Oklahoma county-equivalent median of 802.7 square miles. It accounts for 0.9% of the combined county land area in the state.
See the complete Oklahoma ranking · What counts as a county equivalent?
Population and density of Greer County
The Census Bureau estimates that 5,373 people lived in Greer County on July 1, 2025. That ranks #2,865 of 3,222 county equivalents nationally and #69 of 77 in Oklahoma. Since the April 1, 2020 estimates base of 5,492, the population has declined by 119 (−2.2%), compared with +4.1% for Oklahoma as a whole.
With 639.3 square miles of land, that is 8.4 people per square mile (3.2 per km²), placing Greer County #2,706 nationally for density and #62 in Oklahoma. The median county equivalent has 47 people per square mile; the Oklahoma median is 28. Put another way, there are about 76 acres of land per resident.
| July 1 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|
| Estimate | 5,493 | 5,487 | 5,548 | 5,499 | 5,440 | 5,373 |
| Change | — | −6 | +61 | −49 | −59 | −67 |
U.S. Census Bureau, Vintage 2025 population estimates. Estimates are revised each year and are not decennial census counts. Density divides the whole population by the whole county’s land area, so it describes an average, not how settlement is distributed within the county. Population sources and methods.
Cities and towns in Greer County
3 incorporated places lie at least partly in Greer County. Together they are home to 4,407 people (82%); the other 966 (18%) live outside any incorporated place, in unincorporated communities and rural areas.
The largest is Mangum city, with 2,683 residents in the county. By land, Granite town is the largest at 3.371 mi².
| Incorporated place | Population 2025 | Since 2020 | Land mi² |
|---|---|---|---|
| Mangum cityCounty seat | 2,683 | −3.1% | 1.686 |
| Granite town | 1,609 | −1% | 3.371 |
| Willow town | 115 | −2.5% | 0.262 |
Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Greer County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.
Metropolitan area
Greer County is not part of any metropolitan or micropolitan statistical area in the Office of Management and Budget’s July 2023 delineation; 1,306 other county equivalents are also outside one. These areas are built around an urban core of at least 10,000 people plus the counties tied to it by commuting, so counties outside them are generally rural.
ZIP codes
4 ZIP Code Tabulation Areas have land in Greer County; 3 of them have most of their land inside the county, and the others mainly cover neighboring areas.
73526735477355473673
ZIP Code Tabulation Areas are the Census Bureau’s approximations of USPS ZIP Code service areas, from the 2020 Census relationship files. Lighter codes have less than half of their land in this county. Post-office-box and single-address ZIP Codes have no tabulation area.
Counties bordering Greer County
Greer County shares a land border with 4 county equivalents. It has more land than 1 of them. The largest neighbor is Kiowa County (1,015.1 mi²) and the smallest is Harmon County (537.3 mi²). Together with its neighbors, Greer County forms a block of 3,895.9 mi² of land, of which it holds 16.4%.
| Bordering county equivalent | Land mi² | Size vs. Greer | Compare |
|---|---|---|---|
| Kiowa County | 1,015.1 | 1.6× larger | Compare |
| Beckham County | 901.7 | 1.4× larger | Compare |
| Jackson County | 802.7 | 1.3× larger | Compare |
| Harmon County | 537.3 | 1.2× smaller | Compare |
How big is Greer County compared with U.S. states?
Greer County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 1.6 times as much. Oklahoma’s county land could hold about 107 areas the size of Greer County.
Another way to picture it: the same land area would fill a square about 25.3 miles (40.7 km) on each side. Real county shapes are rarely square, so this is a scale reference rather than a width or driving distance.
State figures are the sums of each state’s county-equivalent land measurements in the same Census release, so states and counties are compared on the same basis. Published state totals can differ slightly because of rounding. Compare all states · Counties bigger than entire states.
What stands out about Greer County?
Greer County has more land than 1,736 of the other 3,221 county equivalents in the dataset.
A median is the middle county-equivalent measurement, not the average of the largest and smallest. All three bars use the same linear scale. Very small areas may appear as a thin sliver; the labels retain their values.
Does including water change its rank?
Using land plus water places Greer County at #1,597 nationally by total area, 111 places farther from the top than its land rank. Other county equivalents gain more area when their water measurements are included.
Its water share is 0.7%, compared with a national county-equivalent median of 1.2% — 0.5 percentage points lower. This describes the statistical geography’s land/water mix, not flood exposure or developable land.
Closest positions in the national land ranking
These entries sit immediately beside Greer County in the national ranking. They can be in different states and are not necessarily geographic neighbors.
| Land rank | County equivalent | Land mi² | Comparison |
|---|---|---|---|
| #1485 | Seward County, Kansas | 639.7 | Compare |
| #1486 | Greer County, Oklahoma | 639.3 | This county |
| #1487 | Clay County, Arkansas | 639.2 | Compare |
Calculated from the same Census release as the area table. Total-area order uses original ALAND + AWATER; water shares and chart labels use published square miles. Calculation details.
Representative coordinates
The Census internal point is 34.933853, -99.552968. It represents a location inside the geography; it is not necessarily the centroid or the address of a courthouse.
Source and precision
U.S. Census Bureau, 2026 Gazetteer Files, Counties. Original ALAND: 1,655,740,219 m²; AWATER: 11,148,547 m². Rankings use ALAND; exact ties use ascending GEOID. Tables preserve Census-published square miles to three decimals, with conversions based on those values.
Common questions
How big is Greer County?
Greer County, Oklahoma has 639.3 square miles (1,655.7 km²) of land and 4.304 square miles of water, for a total area of 643.6 square miles. It ranks #1486 of 3,222 U.S. county equivalents by land area.
Is Greer County the largest county in Oklahoma?
No. Greer County ranks #58 of 77 in Oklahoma by land area. The largest is Osage County, with 2,246.7 square miles of land.
What counties border Greer County?
Greer County shares a land border with Beckham County, Harmon County, Jackson County, and Kiowa County.
What is the population of Greer County?
The Census Bureau estimates Greer County had 5,373 residents on July 1, 2025, ranking #2,865 of 3,222 county equivalents. That is 8.4 people per square mile of land.
What is the county seat of Greer County?
The county seat of Greer County is Mangum.
What cities and towns are in Greer County?
Greer County has 3 incorporated places. The most populous are Mangum city, Granite town, and Willow town; 966 residents live outside any incorporated place.
Is Greer County part of a metropolitan area?
No. Greer County is outside every metropolitan and micropolitan statistical area in the July 2023 OMB delineation.
How many ZIP codes are in Greer County?
4 ZIP Code Tabulation Areas have land in Greer County, and 3 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.
How does Greer County compare with U.S. states?
It has less land than every state. Rhode Island, the smallest, has 1.6 times as much land.
How many acres of land are in Greer County?
The land measurement converts to approximately 409,142 acres. Including water, total area is approximately 411,897 acres. One square mile equals 640 acres.
Why might another source show a different area?
Check whether it reports land or total area, its Census vintage, and its rounding. Our guide explains how to reconcile county area figures.
Can this establish a property boundary?
No. Statistical measurements and generalized maps do not establish property lines. Consult the relevant local surveying or land-records authority.