Umatilla County area

Population and density of Umatilla County

The Census Bureau estimates that 81,119 people lived in Umatilla County on July 1, 2025. That ranks #730 of 3,222 county equivalents nationally and #14 of 36 in Oregon. Since the April 1, 2020 estimates base of 80,071, the population has grown by 1,048 (+1.3%), compared with +0.9% for Oregon as a whole.

With 3,215.5 square miles of land, that is 25 people per square mile (9.7 per km²), placing Umatilla County #2,140 nationally for density and #18 in Oregon. The median county equivalent has 47 people per square mile; the Oregon median is 25. Put another way, there are about 25 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 Umatilla County

12 incorporated places lie at least partly in Umatilla County. Together they are home to 58,910 people (72.6%); the other 22,209 (27.4%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Hermiston city, with 19,906 residents in the county. The county seat, Pendleton city, has 16,989 residents. By land, Pendleton city is the largest at 11.6 mi². Among places with at least 1,000 residents in 2020, Umatilla city grew fastest since then (+11.4%).

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

Metropolitan area

Umatilla County is a central county of the Hermiston-Pendleton, OR Micropolitan Statistical Area. Its 2 county equivalents have 93,721 residents on 5,246 square miles of land; Umatilla County accounts for 61.3% of the land and 86.6% of the residents. By combined land it ranks #18 of 542 micropolitan areas, and #44 by population.

ZIP codes

14 ZIP Code Tabulation Areas have land in Umatilla County; 13 of them have most of their land inside the county, and the others mainly cover neighboring areas.

9780197810978139782697835978389785997862978689787597880978829788699362

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 Umatilla County

Umatilla County shares a land border with 7 county equivalents, including 3 in Washington. It has more land than 6 of them. The largest neighbor is Grant County (4,527.8 mi²) and the smallest is Columbia County (868.6 mi²). Together with its neighbors, Umatilla County forms a block of 18,795.4 mi² of land, of which it holds 17.1%.

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

Umatilla County has more land than 2 of the 50 states. It is about 1.7 times the land area of Delaware (1,948.6 mi²), while Connecticut, the next larger state, has 1.5 times as much land (4,842.5 mi²). Oregon’s county land could hold about 30 areas the size of Umatilla County.

Another way to picture it: the same land area would fill a square about 56.7 miles (91.3 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 Umatilla County?

Umatilla County has more land than 3,062 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 Umatilla County at #172 nationally by total area, 12 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 0.5%, compared with a national county-equivalent median of 1.2% — 0.7 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 Umatilla 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.