Grant County area

Population and density of Grant County

The Census Bureau estimates that 105,727 people lived in Grant County on July 1, 2025. That ranks #600 of 3,222 county equivalents nationally and #13 of 39 in Washington. Since the April 1, 2020 estimates base of 99,135, the population has grown by 6,592 (+6.6%), compared with +3.8% for Washington as a whole.

With 2,679.6 square miles of land, that is 39 people per square mile (15 per km²), placing Grant County #1,765 nationally for density and #20 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.

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 Grant County

15 incorporated places lie at least partly in Grant County. Together they are home to 59,129 people (55.9%); the other 46,598 (44.1%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Moses Lake city, with 27,469 residents in the county. The county seat, Ephrata city, has 8,834 residents. Among places with at least 1,000 residents in 2020, Mattawa city grew fastest since then (+15.7%).

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

Metropolitan area

Grant County is a central county of the Moses Lake, WA Micropolitan Statistical Area. Grant County is the area’s only county equivalent, so the micro area has the same 2,679.6 square miles of land. By combined land it ranks #56 of 542 micropolitan areas, and #28 by population. It belongs to the Moses Lake-Othello, WA Combined Statistical Area.

ZIP codes

19 ZIP Code Tabulation Areas have land in Grant County; 14 of them have most of their land inside the county, and the others mainly cover neighboring areas.

98823988249883298837988489885198853988579886099103991159911699123991339913599321993449934999357

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 Grant County

Grant County shares a land border with 8 county equivalents. It has more land than 6 of them. The largest neighbor is Okanogan County (5,266.2 mi²) and the smallest is Franklin County (1,241.6 mi²). Together with its neighbors, Grant County forms a block of 23,534.1 mi² of land, of which it holds 11.4%.

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

Grant County has more land than 2 of the 50 states. It is about 1.4 times the land area of Delaware (1,948.6 mi²), while Connecticut, the next larger state, has 1.8 times as much land (4,842.5 mi²). Washington’s county land could hold about 25 areas the size of Grant County.

Another way to picture it: the same land area would fill a square about 51.8 miles (83.3 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 Grant County?

Grant County has more land than 3,028 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 Grant County at #202 nationally by total area, 8 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 4%, compared with a national county-equivalent median of 1.2% — 2.8 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 Grant County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

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.