A Look at Population Trends in Eastern Oregon

September 16, 2021

Portland State University’s (PSU) annual population estimates show that Eastern Oregon’s population continued to increase in 2020. This is in line with the long-term trend of a growing population in both the state and the region overall. PSU’s Population Research Center does extensive work to create the annual population estimates for the state and counties, as well as incorporated and unincorporated areas. Detailed data focused on age demographics and the components of population change are also available.

County Change

The population increased in 2020 in five of Eastern Oregon’s eight counties. Grant and Harney counties saw the scale tip the opposite direction while Union County saw no change either way. Growth was 0.3% for the region overall, which represents a decrease from the previous over-the-year growth rate of 0.6%. Eastern Oregon’s over-the-year rate was less than half the state’s growth rate of 0.7%. The five-year-trend (2015 to 2020) for growth was 2.6% in Eastern Oregon, which represents a decrease from the previous five-year-trend (2014 to 2019) of 3.0%. The state’s five-year trend dropped to 6.3% from 6.9%.
Wallowa County saw the least growth for the year among the region’s gainers. The county added 10 residents for a gain of 0.1% with a five-year gain of 0.8%, up 60. Umatilla County welcomed the most new residents (+335) with a gain of 0.4% and a five-year gain of 2,340 or 3.0%.This should come as no surprise given the size of Umatilla’s population relative to other Eastern Oregon counties. In terms of population growth relative to a county’s own size, however, Morrow saw the most growth, gaining 1.1% for the year and a massive 10.3% for the five-year trend. Baker and Malheur have both seen sizable growth over the five-year period with gains of 3.0% and 2.0%, respectively.

Grant County’s five-year loss climbed to 1.5%, down 115 residents since 2015. Harney showed a small decrease for the five-year trend (-0.2%) with a larger decrease over the year, down 1.1% or 80 residents. Union County saw no gain for the year, but rose 0.8% since 2015, adding 215 new residents.

City Change

Incorporated cities in Eastern Oregon totaled 125,237 residents in 2020, two-thirds of the region’s total population. These cities ranged from two residents in Greenhorn to 18,775 residents in Hermiston. Thirty cities had a population under 1,000 with a combined population of 10,167. Over-the-year growth came in at 0.4% or 40 residents for these smaller cities, with few gaining any new residents. Five-year growth was 0.8% or 85 residents with Wallowa City as the stand out, gaining 3.7% or 30 residents.

Twenty-three cities had a population above 1,000 with a combined population of 115,070. Total over-the-year growth came in at 1.0% or 1,100 residents for these larger cities, with seven showing no growth. Five-year growth was 3.9% or 4,345 residents. The accompanying table shows a slightly larger total population because John Day and Canyon City (705 residents) were combined as a single population for this analysis. Immediate geographic proximity makes the two function more like a single economy even though they are two separate cities. This also occurs with La Grande/Island City and Burns/Hines, however, each of these four have populations above 1,000, so they did not affect the table’s total population.
Eastern Oregon’s largest city experienced the most growth in 2020. Hermiston added 360 residents; the city also set the fastest pace with a gain of 2.0%. Hermiston’s five-year gain was 7.2%, adding the most residents there as well, up 1,255. The La Grande/Island City area was second for growth over the year, up 170. The area’s five-year trend was 410 for a gain of 2.9%. The total population of the two-city area was 14,600 in 2020, which ranks third in Eastern Oregon. Pendleton ranks second for size, but added fewer residents at a more leisurely pace, growing 0.7% or 125 residents. Boardman, the eighth largest city in the region at one-third the size of La Grande/Island City, blew the field away in terms of five-year growth. The city grew by 30.7%, adding 1,075 residents and accounting for 90.0% of Morrow County’s five-year gain.

Unincorporated Area Change

Unincorporated areas in Eastern Oregon lost a combined 610 residents (-0.9%) in 2020, but gained 325 residents (+0.5%) since 2015. County land that does not fall within city boundaries had a total population of 63,648. Umatilla, Malheur, and Union counties ranked first through third, respectively, and accounted for nearly three-fourths of Eastern Oregon’s unincorporated population.
Baker and Malheur were the only two counties with population gains in unincorporated areas since 2015. Five counties saw a decrease while Morrow saw no change. Over-the-year growth was positive in three counties and negative in four. Wallowa County saw no change over the year.

City boundary growth played a relatively small role in changes over the year as the total population lost from unincorporated areas to cities through annexation was 106. The largest population change due to boundary growth was in Malheur County where Ontario added 50 residents through annexation. However, even with the drag from annexation unincorporated areas of the county still gained 20 residents in 2020. Other cities that added population through annexation in 2020 were Hermiston (+24), Pendleton (+11), and Stanfield (+2) in Umatilla County; La Grande (+13) in Union County; and John Day (+6) in Grant County.