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Oregon -- Population -- Statistics, Demographic surveys -- Oregon, Population forecasting -- Oregon -- Gilliam County


Different parts of the County experience different growth patterns. Local trends within UGBs and the area outside them collectively influence population growth rates for the County as a whole. UGBs in Gilliam County include Arlington, Condon, and Lonerock.

Gilliam County’s total population declined slightly in the 2000s; however, its largest sub-area, Arlington, experienced population growth during this period.

The population growth that did occur in Gilliam County in the 2000s was largely the result of net in-migration. An aging population not only led to an increase in deaths but also resulted in a smaller proportion of women in their childbearing years. This, along with more women having fewer children and having them at older ages has led to births stagnating in recent years. A larger number of deaths relative to births caused a natural decrease (more deaths than births) in almost every year from 2001 to 2017, resulting in steady population decline.

Total population in Gilliam County as a whole, as well as within its sub-areas, will likely decrease at a quicker pace in the near-term (2019 to 2044) compared to the long-term. Population decline is largely driven by natural decrease outpacing net in-migration. Gilliam County’s total population is forecast to decline by roughly 48 people over the next 25 years (2019-2044) and by 58 in total over the entire 50-year period (2019-2069).


This report is published by the Population Research Center at Portland State University, and is a product of the Oregon Population Forecast Program.

The introductory presentation, preliminary forecast presentation, and Gilliam County final forecast tables are attached to this document as supplemental files.

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Gilliam_County_Sept2018_0.pdf (2725 kB)
Gilliam County Introductory Presentation Sept. 2018

R2_Gilliam_032019.pdf (559 kB)
Gilliam County Preliminary Presentation 3/13/19

Gilliam_Final_Forecast.xlsx (64 kB)
Gilliam County Final Forecast Tables