County outline
Where Grays Harbor County is located
Area breakdown
Land accounts for 85.5% of Grays Harbor County’s measured area and water for 14.5%. Its combined area converts to 5,759.1 square kilometers or approximately 1,423,106 acres.
Green: land · blue: water
| Measurement | Square miles | Square kilometers | Acres |
|---|---|---|---|
| Land | 1,902.268 | 4,926.852 | 1,217,451.5 |
| Water | 321.335 | 832.254 | 205,654.4 |
| Total | 2,223.603 | 5,759.105 | 1,423,105.9 |
How Grays Harbor County compares
By original Census land area, Grays Harbor County ranks #15 of 39 in Washington and #301 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.
Its land area is 1.094 times the Washington county-equivalent median of 1,738.8 square miles. It accounts for 2.9% of the combined county land area in the state.
See the complete Washington ranking · What counts as a county equivalent?
Population and density of Grays Harbor County
The Census Bureau estimates that 78,144 people lived in Grays Harbor County on July 1, 2025. That ranks #747 of 3,222 county equivalents nationally and #19 of 39 in Washington. Since the April 1, 2020 estimates base of 75,635, the population has grown by 2,509 (+3.3%), compared with +3.8% for Washington as a whole.
With 1,902.3 square miles of land, that is 41 people per square mile (16 per km²), placing Grays Harbor County #1,728 nationally for density and #19 in Washington. The median county equivalent has 47 people per square mile; the Washington median is 39. Put another way, there are about 16 acres of land per resident.
| July 1 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|
| Estimate | 75,866 | 76,889 | 77,108 | 77,582 | 78,020 | 78,144 |
| Change | — | +1,023 | +219 | +474 | +438 | +124 |
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 Grays Harbor County
9 incorporated places lie at least partly in Grays Harbor County. Together they are home to 48,220 people (61.7%); the other 29,924 (38.3%) live outside any incorporated place, in unincorporated communities and rural areas.
The largest is Aberdeen city, with 17,088 residents in the county. The county seat, Montesano city, has 4,181 residents. By land, Montesano city is the largest at 10.9 mi². Among places with at least 1,000 residents in 2020, Ocean Shores city grew fastest since then (+17.6%).
| Incorporated place | Population 2025 | Since 2020 | Land mi² |
|---|---|---|---|
| Aberdeen city | 17,088 | +0.4% | 10.9 |
| Hoquiam city | 8,710 | −0.7% | 9.544 |
| Ocean Shores city | 7,892 | +17.6% | 8.517 |
| Montesano cityCounty seat | 4,181 | +0.7% | 10.9 |
| Elma city | 3,534 | +2.8% | 2.764 |
| Westport city | 2,372 | +7.1% | 3.675 |
| McCleary city | 2,053 | +2.8% | 2.05 |
| Cosmopolis city | 1,656 | +1.7% | 1.392 |
| Oakville city | 734 | +2.5% | 0.552 |
Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Grays Harbor County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.
Metropolitan area
Grays Harbor County is a central county of the Aberdeen, WA Micropolitan Statistical Area. Grays Harbor County is the area’s only county equivalent, so the micro area has the same 1,902.3 square miles of land. By combined land it ranks #85 of 542 micropolitan areas, and #79 by population.
ZIP codes
22 ZIP Code Tabulation Areas have land in Grays Harbor County; 20 of them have most of their land inside the county, and the others mainly cover neighboring areas.
98520985269853598536985379854198547985509855298557985599856298563985669856898569985719857598579985839858798595
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 Grays Harbor County
Grays Harbor County shares a land border with 5 county equivalents. It has more land than 4 of them. The largest neighbor is Lewis County (2,402.8 mi²) and the smallest is Thurston County (722.5 mi²). Together with its neighbors, Grays Harbor County forms a block of 8,724.2 mi² of land, of which it holds 21.8%.
| Bordering county equivalent | Land mi² | Size vs. Grays Harbor | Compare |
|---|---|---|---|
| Lewis County | 2,402.8 | 1.3× larger | Compare |
| Jefferson County | 1,803.7 | 1.1× smaller | Compare |
| Mason County | 959.6 | 2× smaller | Compare |
| Pacific County | 933.4 | 2× smaller | Compare |
| Thurston County | 722.5 | 2.6× smaller | Compare |
How big is Grays Harbor County compared with U.S. states?
Grays Harbor County has more land than 1 of the 50 states. It is about 1.8 times the land area of Rhode Island (1,033.9 mi²), while Delaware, the next larger state, has 1 times as much land (1,948.6 mi²). Washington’s county land could hold about 35 areas the size of Grays Harbor County.
Another way to picture it: the same land area would fill a square about 43.6 miles (70.2 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 Grays Harbor County?
Grays Harbor County has more land than 2,921 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 Grays Harbor County at #281 nationally by total area, 20 places closer to the top than its land rank. The water assigned to this geography moves it ahead of some county equivalents with more land.
Its water share is 14.5%, compared with a national county-equivalent median of 1.2% — 13.3 percentage points higher. 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 Grays Harbor County in the national ranking. They can be in different states and are not necessarily geographic neighbors.
| Land rank | County equivalent | Land mi² | Comparison |
|---|---|---|---|
| #300 | Santa Fe County, New Mexico | 1,910.4 | Compare |
| #301 | Grays Harbor County, Washington | 1,902.3 | This county |
| #302 | Miami-Dade County, Florida | 1,900 | 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 47.111723, -123.826904. 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: 4,926,850,675 m²; AWATER: 832,254,159 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 Grays Harbor County?
Grays Harbor County, Washington has 1,902.3 square miles (4,926.9 km²) of land and 321.3 square miles of water, for a total area of 2,223.6 square miles. It ranks #301 of 3,222 U.S. county equivalents by land area.
Is Grays Harbor County the largest county in Washington?
No. Grays Harbor County ranks #15 of 39 in Washington by land area. The largest is Okanogan County, with 5,266.2 square miles of land.
What counties border Grays Harbor County?
Grays Harbor County shares a land border with Mason County, Jefferson County, Pacific County, Thurston County, and Lewis County.
What is the population of Grays Harbor County?
The Census Bureau estimates Grays Harbor County had 78,144 residents on July 1, 2025, ranking #747 of 3,222 county equivalents. That is 41 people per square mile of land.
What is the county seat of Grays Harbor County?
The county seat of Grays Harbor County is Montesano.
What cities and towns are in Grays Harbor County?
Grays Harbor County has 9 incorporated places. The most populous five are Aberdeen city, Hoquiam city, Ocean Shores city, Montesano city, and Elma city; 29,924 residents live outside any incorporated place.
Is Grays Harbor County part of a metropolitan area?
Yes. It is a central county of the Aberdeen, WA Micropolitan Statistical Area.
How many ZIP codes are in Grays Harbor County?
22 ZIP Code Tabulation Areas have land in Grays Harbor County, and 20 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.
How does Grays Harbor County compare with U.S. states?
It has more land than 1 of the 50 states, including Rhode Island (1,033.9 square miles of land).
How many acres of land are in Grays Harbor County?
The land measurement converts to approximately 1,217,452 acres. Including water, total area is approximately 1,423,106 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.