Okanogan County area

Okanogan County, Washington covers 5,312.7 square miles: 5,266.2 square miles of land and 46.5 square miles of water. Its county seat is Okanogan. An estimated 45,230 people lived there in 2025.

Official Census measurements · GEOID 530472026 Gazetteer · retrieved September 27, 2026
Land area5,266.2 mi²
Water area46.5 mi²
Population (2025)45,230
People per mi²8.6

County outline

Generalized outline of Okanogan County, Washington
2025 Census cartographic boundary, fitted to this frame. County maps are not at a common scale. The 2026 area measurements below come from the separate Gazetteer release. Map source and limitations.

Where Okanogan County is located

Okanogan County highlighted on a map of all U.S. county equivalents. About the maps

Area breakdown

Land accounts for 99.1% of Okanogan County’s measured area and water for 0.9%. Its combined area converts to 13,759.8 square kilometers or approximately 3,400,124 acres.

Green: land · blue: water

MeasurementSquare milesSquare kilometersAcres
Land5,266.19313,639.3773,370,363.5
Water46.5120.43429,760
Total5,312.69313,759.8123,400,123.5

How Okanogan County compares

By original Census land area, Okanogan County ranks #1 of 39 in Washington and #73 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.

Its land area is 3.029 times the Washington county-equivalent median of 1,738.8 square miles. It accounts for 7.9% of the combined county land area in the state.

See the complete Washington ranking · What counts as a county equivalent?

Population and density of Okanogan County

The Census Bureau estimates that 45,230 people lived in Okanogan County on July 1, 2025. That ranks #1,107 of 3,222 county equivalents nationally and #26 of 39 in Washington. Since the April 1, 2020 estimates base of 42,097, the population has grown by 3,133 (+7.4%), compared with +3.8% for Washington as a whole.

With 5,266.2 square miles of land, that is 8.6 people per square mile (3.3 per km²), placing Okanogan County #2,695 nationally for density and #34 in Washington. The median county equivalent has 47 people per square mile; the Washington median is 39. Put another way, there are about 75 acres of land per resident.

Estimated population, 2020–2025 · line scaled to this county’s own range
July 1202020212022202320242025
Estimate42,14342,76143,13843,72244,64845,230
Change—+618+377+584+926+582

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 Okanogan County

13 incorporated places lie at least partly in Okanogan County. Together they are home to 17,281 people (38.2%); the other 27,949 (61.8%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Omak city, with 5,185 residents in the county. The county seat, Okanogan city, has 2,494 residents. Among places with at least 1,000 residents in 2020, Omak city grew fastest since then (+6.7%).

Incorporated placePopulation 2025Since 2020Land mi²
Omak city5,185+6.7%3.801
Okanogan cityCounty seat2,494+5%2.015
Brewster city2,093+5.5%1.152
Oroville city1,935+6.6%1.69
Tonasket city1,133+2.9%0.944
Twisp town1,126+13.1%1.169
Coulee Dam townAlso in 2 other counties1,040+2.7%0.716
Pateros city654+9%0.505
Winthrop town624+24.3%0.974
Riverside town343+4.9%0.887
Elmer City town258+5.7%0.238
Conconully town198+3.7%0.211
Nespelem town198+11.2%0.194

Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Okanogan County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.

Metropolitan area

Okanogan 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

22 ZIP Code Tabulation Areas have land in Okanogan County; 19 of them have most of their land inside the county, and the others mainly cover neighboring areas.

98812988139881498816988199882798829988339883498840988419884498846988499885598856988599886299116991249915599166

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 Okanogan County

Okanogan County shares a land border with 7 county equivalents. It has more land than every one of them. The largest neighbor is Chelan County (2,921.2 mi²) and the smallest is Skagit County (1,730.2 mi²). Together with its neighbors, Okanogan County forms a block of 21,038.2 mi² of land, of which it holds 25%.

Map of Okanogan County and the 7 county equivalents that border it Ferry County, Washington: 2,203.2 mi² landDouglas County, Washington: 1,819.2 mi² landChelan County, Washington: 2,921.2 mi² landWhatcom County, Washington: 2,107.9 mi² landSkagit County, Washington: 1,730.2 mi² landLincoln County, Washington: 2,310.6 mi² landGrant County, Washington: 2,679.6 mi² land
Okanogan County (dark) and its bordering county equivalents. Select a neighbor to open its profile. Drawn from the 2025 Census cartographic boundaries in an equal-area projection. How borders are determined.
Bordering county equivalentLand mi²Size vs. OkanoganCompare
Chelan County2,921.21.8× smallerCompare
Grant County2,679.62× smallerCompare
Lincoln County2,310.62.3× smallerCompare
Ferry County2,203.22.4× smallerCompare
Whatcom County2,107.92.5× smallerCompare
Douglas County1,819.22.9× smallerCompare
Skagit County1,730.23× smallerCompare

How big is Okanogan County compared with U.S. states?

Okanogan County has more land than 3 of the 50 states. It is about 1.1 times the land area of Connecticut (4,842.5 mi²), while Hawaii, the next larger state, has 1.2 times as much land (6,422.6 mi²). Washington’s county land could hold about 13 areas the size of Okanogan County.

Land area: Okanogan County and the closest-sized states
Connecticut4,842.5 mi²
Okanogan County5,266.2 mi²
Hawaii6,422.6 mi²

Another way to picture it: the same land area would fill a square about 72.6 miles (116.8 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 Okanogan County?

Okanogan County has more land than 3,149 of the other 3,221 county equivalents in the dataset.

Land area compared with the typical county equivalent
Okanogan County5,266.2 mi²
Washington median1,738.8 mi²
National median604.5 mi²

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 Okanogan County at #76 nationally by total area, 3 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 Okanogan County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

Land rankCounty equivalentLand mi²Comparison
#72Prince of Wales-Hyder Census Area, Alaska5,268.2Compare
#73Okanogan County, Washington5,266.2This county
#74Garfield County, Utah5,179.6Compare

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 48.548453, -119.742235. 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: 13,639,376,673 m²; AWATER: 120,435,129 m². Rankings use ALAND; exact ties use ascending GEOID. Tables preserve Census-published square miles to three decimals, with conversions based on those values.

Download the official county source ZIP ↗ · Methodology

Common questions

How big is Okanogan County?

Okanogan County, Washington has 5,266.2 square miles (13,639.4 km²) of land and 46.5 square miles of water, for a total area of 5,312.7 square miles. It ranks #73 of 3,222 U.S. county equivalents by land area.

Is Okanogan County the largest county in Washington?

Yes. Okanogan County has the most land of the 39 county equivalents in Washington.

What counties border Okanogan County?

Okanogan County shares a land border with Ferry County, Douglas County, Chelan County, Whatcom County, Skagit County, Lincoln County, and Grant County.

What is the population of Okanogan County?

The Census Bureau estimates Okanogan County had 45,230 residents on July 1, 2025, ranking #1,107 of 3,222 county equivalents. That is 8.6 people per square mile of land.

What is the county seat of Okanogan County?

The county seat of Okanogan County is Okanogan.

What cities and towns are in Okanogan County?

Okanogan County has 13 incorporated places. The most populous five are Omak city, Okanogan city, Brewster city, Oroville city, and Tonasket city; 27,949 residents live outside any incorporated place.

Is Okanogan County part of a metropolitan area?

No. Okanogan County is outside every metropolitan and micropolitan statistical area in the July 2023 OMB delineation.

How many ZIP codes are in Okanogan County?

22 ZIP Code Tabulation Areas have land in Okanogan County, and 19 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.

How does Okanogan County compare with U.S. states?

It has more land than 3 of the 50 states, including Connecticut (4,842.5 square miles of land).

How many acres of land are in Okanogan County?

The land measurement converts to approximately 3,370,364 acres. Including water, total area is approximately 3,400,124 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.

Cite this county

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