Quick Facts
| County seat | Pendleton |
|---|---|
| Region | Eastern Oregon |
| Population (2020 Census) | 81,119 |
| Land & water area | 3,215 sq mi |
| Population density | 25.2 people per sq mi |
| Established | 1862 |
| Formed from | Central portion of Wasco County |
| Name origin | Named for the adjacent Umatilla River, derived from a Sahaptin, word possibly meaning laughing waters. |
| Incorporated cities | 12 |
| Main electric utility | Pacific Power / Umatilla Electric Cooperative |
| FIPS code | 41059 |
| Official county website | co.umatilla.or.us |
About Umatilla County
Umatilla County () is one of the 36 counties in the U.S. state of Oregon. Its 2020 population of 80,075 ranks it as the 14th largest in Oregon, and largest in Eastern Oregon. Hermiston is the largest and fastest growing city in Umatilla County, but Pendleton remains the county seat. Umatilla County is part of the Hermiston-Pendleton, OR Micropolitan Statistical Area, which has a combined population of 94,833. It is included in the eight-county definition of Eastern Oregon.
The county is named for the Umatilla River.
Source: adapted from Wikipedia, available under CC BY-SA 4.0.
Cities in Umatilla County
| City | Population (2020) | Incorporated |
|---|---|---|
| Hermiston | 19,354 | 1907 |
| Pendleton ★ | 17,107 | 1880 |
| Umatilla | 7,363 | 1864 |
| Milton-Freewater | 7,151 | 1950 |
| Stanfield | 2,144 | 1910 |
| Pilot Rock | 1,328 | 1911 |
| Athena | 1,209 | 1904 |
| Weston | 706 | 1878 |
| Echo | 632 | 1904 |
| Adams | 389 | 1893 |
| Helix | 194 | 1903 |
| Ukiah | 159 | 1969 |
★ county seat. Cities that span more than one county are listed in each.