County outline
Where Dewey County is located
Area breakdown
Land accounts for 99.1% of Dewey County’s measured area and water for 0.9%. Its combined area converts to 2,611.7 square kilometers or approximately 645,364 acres.
Green: land · blue: water
| Measurement | Square miles | Square kilometers | Acres |
|---|---|---|---|
| Land | 999.628 | 2,589.025 | 639,761.9 |
| Water | 8.753 | 22.67 | 5,601.9 |
| Total | 1,008.381 | 2,611.695 | 645,363.8 |
How Dewey County compares
By original Census land area, Dewey County ranks #21 of 77 in Oklahoma and #681 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.
Its land area is 1.245 times the Oklahoma county-equivalent median of 802.7 square miles. It accounts for 1.5% of the combined county land area in the state.
See the complete Oklahoma ranking · What counts as a county equivalent?
Population and density of Dewey County
The Census Bureau estimates that 4,207 people lived in Dewey County on July 1, 2025. That ranks #2,946 of 3,222 county equivalents nationally and #71 of 77 in Oklahoma. Since the April 1, 2020 estimates base of 4,483, the population has declined by 276 (−6.2%), compared with +4.1% for Oklahoma as a whole.
With 999.6 square miles of land, that is 4.2 people per square mile (1.6 per km²), placing Dewey County #2,887 nationally for density and #71 in Oklahoma. The median county equivalent has 47 people per square mile; the Oklahoma median is 28. Put another way, there are about 152 acres of land per resident.
| July 1 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|
| Estimate | 4,476 | 4,425 | 4,394 | 4,258 | 4,271 | 4,207 |
| Change | — | −51 | −31 | −136 | +13 | −64 |
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 Dewey County
7 incorporated places lie at least partly in Dewey County. Together they are home to 2,307 people (54.8%); the other 1,900 (45.2%) live outside any incorporated place, in unincorporated communities and rural areas.
The largest is Seiling city, with 800 residents in the county (the city extends into 1 other county). The county seat, Taloga town, has 270 residents.
| Incorporated place | Population 2025 | Since 2020 | Land mi² |
|---|---|---|---|
| Seiling cityAlso in 1 other county | 800 | −5.9% | 1.207 |
| Vici town | 576 | −6% | 0.434 |
| Leedey town | 384 | −7% | 0.45 |
| Taloga townCounty seat | 270 | −6.6% | 0.516 |
| Camargo town | 182 | −5.7% | 0.249 |
| Oakwood town | 69 | −8% | 0.237 |
| Putnam town | 26 | −3.7% | 0.085 |
Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Dewey County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.
Metropolitan area
Dewey 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
12 ZIP Code Tabulation Areas have land in Dewey County; 7 of them have most of their land inside the county, and the others mainly cover neighboring areas.
736467365473658736597366373667736697372473755738357385373859
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 Dewey County
Dewey County shares a land border with 6 county equivalents. It has more land than 3 of them. The largest neighbor is Woodward County (1,242.8 mi²) and the smallest is Blaine County (928.5 mi²). Together with its neighbors, Dewey County forms a block of 7,487.3 mi² of land, of which it holds 13.4%.
| Bordering county equivalent | Land mi² | Size vs. Dewey | Compare |
|---|---|---|---|
| Woodward County | 1,242.8 | 1.2× larger | Compare |
| Ellis County | 1,231.5 | 1.2× larger | Compare |
| Roger Mills County | 1,141.1 | 1.1× larger | Compare |
| Custer County | 988.8 | about the same | Compare |
| Major County | 955 | about the same | Compare |
| Blaine County | 928.5 | 1.1× smaller | Compare |
How big is Dewey County compared with U.S. states?
Dewey 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 times as much. Oklahoma’s county land could hold about 69 areas the size of Dewey County.
Another way to picture it: the same land area would fill a square about 31.6 miles (50.9 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 Dewey County?
Dewey County has more land than 2,541 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 Dewey County at #765 nationally by total area, 84 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 0.9%, compared with a national county-equivalent median of 1.2% — 0.3 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 Dewey County in the national ranking. They can be in different states and are not necessarily geographic neighbors.
| Land rank | County equivalent | Land mi² | Comparison |
|---|---|---|---|
| #680 | Grant County, Oklahoma | 1,000.7 | Compare |
| #681 | Dewey County, Oklahoma | 999.6 | This county |
| #682 | Clearwater County, Minnesota | 999 | 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 35.977355, -99.014740. 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: 2,589,024,011 m²; AWATER: 22,668,873 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 Dewey County?
Dewey County, Oklahoma has 999.6 square miles (2,589 km²) of land and 8.753 square miles of water, for a total area of 1,008.4 square miles. It ranks #681 of 3,222 U.S. county equivalents by land area.
Is Dewey County the largest county in Oklahoma?
No. Dewey County ranks #21 of 77 in Oklahoma by land area. The largest is Osage County, with 2,246.7 square miles of land.
What counties border Dewey County?
Dewey County shares a land border with Custer County, Blaine County, Woodward County, Major County, Roger Mills County, and Ellis County.
What is the population of Dewey County?
The Census Bureau estimates Dewey County had 4,207 residents on July 1, 2025, ranking #2,946 of 3,222 county equivalents. That is 4.2 people per square mile of land.
What is the county seat of Dewey County?
The county seat of Dewey County is Taloga.
What cities and towns are in Dewey County?
Dewey County has 7 incorporated places. The most populous five are Seiling city, Vici town, Leedey town, Taloga town, and Camargo town; 1,900 residents live outside any incorporated place.
Is Dewey County part of a metropolitan area?
No. Dewey County is outside every metropolitan and micropolitan statistical area in the July 2023 OMB delineation.
How many ZIP codes are in Dewey County?
12 ZIP Code Tabulation Areas have land in Dewey County, and 7 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.
How does Dewey County compare with U.S. states?
It has less land than every state. Rhode Island, the smallest, has 1 times as much land.
How many acres of land are in Dewey County?
The land measurement converts to approximately 639,762 acres. Including water, total area is approximately 645,364 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.