WA · GEOID 53045

Mason County area

Mason County, Washington covers 1,051 square miles: 959.6 square miles of land and 91.5 square miles of water.

Official Census measurements2026 Gazetteer · retrieved September 27, 2026
Land area959.6 mi²
Water area91.5 mi²
Total area1,051 mi²
National land rank#731

County outline

Generalized outline of Mason 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 Mason County is located

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

Area breakdown

Land accounts for 91.3% of Mason County’s measured area and water for 8.7%. Its combined area converts to 2,722.2 square kilometers or approximately 672,668 acres.

Green: land · blue: water

MeasurementSquare milesSquare kilometersAcres
Land959.5652,485.262614,121.6
Water91.478236.92758,545.9
Total1,051.0432,722.189672,667.5

How Mason County compares

By original Census land area, Mason County ranks #29 of 39 in Washington and #731 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.

Its land area is 0.552 times the Washington county-equivalent median of 1,738.8 square miles. It accounts for 1.4% of the combined county land area in the state.

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

What stands out about Mason County?

Mason County has more land than 2,491 of the other 3,221 county equivalents in the dataset.

Land area compared with the typical county equivalent
Mason County959.6 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 Mason County at #720 nationally by total area, 11 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 8.7%, compared with a national county-equivalent median of 1.2% — 7.5 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 Mason County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

Land rankCounty equivalentLand mi²Comparison
#730Colorado County, Texas960.3Compare
#731Mason County, Washington959.6This county
#732Hill County, Texas958.9Compare

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 47.350832, -123.173103. 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: 2,485,261,386 m²; AWATER: 236,927,322 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 many acres of land are in Mason County?

The land measurement converts to approximately 614,122 acres. Including water, total area is approximately 672,668 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

Download the complete CSV or JSON dataset