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Umatilla County, Oregon facts for kids

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Umatilla County
Stafford Hansell Government Center in Hermiston
Stafford Hansell Government Center in Hermiston
Map of Oregon highlighting Umatilla County
Location within the U.S. state of Oregon
Map of the United States highlighting Oregon
Oregon's location within the U.S.
Country  United States
State  Oregon
Founded September 27, 1862
Seat Pendleton
Largest city Hermiston
 • Total 3,231 sq mi (8,370 km2)
 • Land 3,216 sq mi (8,330 km2)
 • Water 16 sq mi (40 km2)  0.5%%
 • Total 80,075
 • Estimate 
79,988 Decrease
 • Density 20/sq mi (9/km2)
Time zone UTC−8 (Pacific)
 • Summer (DST) UTC−7 (PDT)
Congressional district 2nd

Umatilla County is one of the 36 counties in the U.S. state of Oregon. As of the 2020 census, the population was 80,075. Hermiston is the largest 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 92,261. It is included in the eight-county definition of Eastern Oregon.

The county is named for the Umatilla River.


Umatilla County was created on September 27, 1862, out of a portion of Wasco County. Adjustments were made to the county's boundaries following the creation of Grant, Morrow, Union, and Wallowa Counties. This legislative act also designated Marshall Station as the temporary county seat. An 1865 election selected Umatilla City, now known as Umatilla, as the county seat. With the development of wheat farming, population shifted to the north and east parts of the county, and a subsequent election in 1868 moved the county seat again to Pendleton.

The Umatilla Indian Reservation was established by the Treaty of Walla Walla in 1855. The Umatillas, Walla Wallas, and Cayuse tribes were resettled there, and is located immediately southeast of Pendleton.

EZ Wireless of Hermiston officially opened on February 4, 2004, one of the largest known Wi-Fi wide area networks in the United States, covering parts of Umatilla County, Morrow County and Benton County, Washington. Although created to facilitate communications among local police, firemen and EMT workers who immediately respond to possible accidents or terrorist attacks on the Umatilla Chemical Depot, where the U.S. Army maintained a national arsenal of nerve gas, the network can be accessed in some places by the public for free.


According to the U.S. Census Bureau, the county has a total area of 3,231 square miles (8,370 km2), of which 3,216 square miles (8,330 km2) is land and 16 square miles (41 km2) (0.5%) is water. It borders the Columbia River across from Washington.

Adjacent counties

I-84 eastbound and McKay Reservoir in Umatilla County

National protected areas


Historical population
Census Pop.
1870 2,916
1880 9,607 229.5%
1890 13,381 39.3%
1900 18,049 34.9%
1910 20,309 12.5%
1920 25,946 27.8%
1930 24,399 −6.0%
1940 26,030 6.7%
1950 41,703 60.2%
1960 44,352 6.4%
1970 44,923 1.3%
1980 58,861 31.0%
1990 59,249 0.7%
2000 70,548 19.1%
2010 75,889 7.6%
2020 80,075 5.5%
2021 (est.) 79,988 5.4%
U.S. Decennial Census
1790-1960 1900-1990
1990-2000 2010-2020

2010 census

As of the 2010 census, 75,889 people, 26,904 households, and 18,647 families resided in the county. The population density was 23.6 inhabitants per square mile (9.1/km2). The 29,693 housing units had an average density of 9.2 per square mile (3.6/km2). The racial makeup of the county was 79.1% White, 3.5% American Indian, 0.9% Asian, 0.8% Black or African American, 0.1% Pacific islander, 12.5% from other races, and 3.1% from two or more races. Those of Hispanic or Latino origin made up 23.9% of the population. In terms of ancestry, 21.4% were German, 12.8% were Irish, 11.6% were English, and 5.6% were American.

Of the 26,904 households, 36.4% had children under the age of 18 living with them, 50.9% were married couples living together, 12.0% had a female householder with no husband present, 30.7% were non-families, and 24.7% of all households were made up of individuals. The average household size was 2.67 and the average family size was 3.17. The median age was 35.7 years.

The median income for a household in the county was $45,861 and for a family was $53,585. Males had a median income of $39,288 versus $30,489 for females. The per capita income for the county was $20,035. About 11.0% of families and 15.8% of the population were below the poverty line, including 21.4% of those under age 18 and 9.5% of those age 65 or over.

2016 Census household incomes

Strong economic growth in the west end of the county has propelled Hermiston well past Pendleton with the highest median household incomes in Umatilla County.

2016 Median household incomes
Rank City Median Income % Change from 2010
1 Hermiston $49,008 +15.1%
2 Pendleton $46,190 +1.6%
3 Umatilla $41,818 -0.1%
4 Milton-Freewater $37,077 +9.2%


Ontario trestle
Trestle seen off Sparks Station Rd at Pendleton Country Club, opposite of the McKay Reservoir, Pendleton, Oregon. Transportation linkages in Umatilla are one of the county's major advantages.
Steen Road Grain Elevator (Umatilla County, Oregon scenic images) (umaDA0088)
An old grain elevator along Steen Road south of Milton-Freewater, Umatilla County.

Umatilla County is generally divided into three distinct economic and cultural areas, which are the "West-End," the Pendleton-area, and the Milton-Freewater-area. Although each of these communities shares some economic ties, the distance between each creates three very distinct communities. The West-End includes the communities of Hermiston, Umatilla, Stanfield, and Echo. The Pendleton-area includes Pendleton, as well as Pilot Rock, Adams, and Athena. The Milton-Freewater-area is largely tied to the Walla Walla, Washington area, and is considered a part of the Walla Walla Metropolitan Planning Organization. The similarities between the areas has created a long-standing rivalry, particularly between the West-End and the Pendleton-area, with regard to economic opportunity and public resources. The West-End, led by Hermiston as its largest city, is now nearly twice the size of the Pendleton area, and is projected to be nearly three times the size of the Pendleton area by the year 2035.


Census-designated places

Unincorporated communities


The gold rush of 1862 brought miners and stock raisers to the mountains and grasslands of Umatilla County. Another stimulus was the arrival of the railroad in 1881, opening the region to the development of dry-land wheat farming. Water for irrigation has been key to economic diversification and growth, most recently in the Hermiston area, where potatoes, onions, corn, and more than 200 other crops are grown commercially. Low-cost power through Umatilla Electric Cooperative and good freeway access are also driving growth in the Hermiston area, with developing large data-center operations there, and major distribution facilities for Walmart, FedEx, and UPS are all located in Hermiston.

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