Data / Rankings / Population aged 18 to 64 / Counties in Washington

Counties in Washington by population aged 18 to 64

Whitman County had the highest population aged 18 to 64 of 39 counties in 2015, at 74.1%. Wahkiakum County had the lowest, at 52.4%. The median was 58.3% and the figure for Washington was 63%. Source: the U.S. Census Bureau.

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Highest74.1Whitman County
Lowest52.4Wahkiakum County
Median58.339 counties
Washington63History

Map of counties, 2015

Adams County: 55.2 %Asotin County: 57.6 %Benton County: 59.4 %Chelan County: 58.3 %Clallam County: 54.7 %Clark County: 60.8 %Columbia County: 54.8 %Cowlitz County: 58.7 %Douglas County: 57.8 %Ferry County: 57.5 %Franklin County: 58.6 %Garfield County: 55 %Grant County: 57.1 %Grays Harbor County: 59.6 %Island County: 58.3 %Jefferson County: 53.1 %King County: 66.8 %Kitsap County: 62.7 %Kittitas County: 65.2 %Klickitat County: 58.3 %Lewis County: 57.7 %Lincoln County: 53.6 %Mason County: 59 %Okanogan County: 56.1 %Pacific County: 54.3 %Pend Oreille County: 55.9 %Pierce County: 63.3 %San Juan County: 55.3 %Skagit County: 58 %Skamania County: 61.9 %Snohomish County: 64.3 %Spokane County: 62.3 %Stevens County: 56.6 %Thurston County: 62.1 %Wahkiakum County: 52.4 %Walla Walla County: 61.4 %Whatcom County: 63.6 %Whitman County: 74.1 %Yakima County: 57.5 %
  • Under 55
  • 55 to 57
  • 57 to 58
  • 58 to 59
  • 59 to 63
  • 63 and over
%, 2015. Source: Invokely calculation with data from U.S. Census Bureau. Boundaries: U.S. Census Bureau cartographic boundary files.

All counties, 2015

Whitman County: 74.1 %Whitman County74.1King County: 66.8 %King County66.8Kittitas County: 65.2 %Kittitas County65.2Snohomish County: 64.3 %Snohomish County64.3Whatcom County: 63.6 %Whatcom County63.6Pierce County: 63.3 %Pierce County63.3Kitsap County: 62.7 %Kitsap County62.7Spokane County: 62.3 %Spokane County62.3Thurston County: 62.1 %Thurston County62.1Skamania County: 61.9 %Skamania County61.9Walla Walla County: 61.4 %Walla Walla County61.4Clark County: 60.8 %Clark County60.8Grays Harbor County: 59.6 %Grays Harbor County59.6Benton County: 59.4 %Benton County59.4Mason County: 59 %Mason County59Cowlitz County: 58.7 %Cowlitz County58.7Franklin County: 58.6 %Franklin County58.6Chelan County: 58.3 %Chelan County58.3Island County: 58.3 %Island County58.3Klickitat County: 58.3 %Klickitat County58.3Skagit County: 58 %Skagit County58Douglas County: 57.8 %Douglas County57.8Lewis County: 57.7 %Lewis County57.7Asotin County: 57.6 %Asotin County57.6Yakima County: 57.5 %Yakima County57.5Ferry County: 57.5 %Ferry County57.5Grant County: 57.1 %Grant County57.1Stevens County: 56.6 %Stevens County56.6Okanogan County: 56.1 %Okanogan County56.1Pend Oreille County: 55.9 %Pend Oreille County55.9San Juan County: 55.3 %San Juan County55.3Adams County: 55.2 %Adams County55.2Garfield County: 55 %Garfield County55Columbia County: 54.8 %Columbia County54.8Clallam County: 54.7 %Clallam County54.7Pacific County: 54.3 %Pacific County54.3Lincoln County: 53.6 %Lincoln County53.6Jefferson County: 53.1 %Jefferson County53.1Wahkiakum County: 52.4 %Wahkiakum County52.4Whitman County: 74.1 %Whitman County74.1King County: 66.8 %King County66.8Kittitas County: 65.2 %Kittitas County65.2Snohomish County: 64.3 %Snohomish County64.3Whatcom County: 63.6 %Whatcom County63.6Pierce County: 63.3 %Pierce County63.3Kitsap County: 62.7 %Kitsap County62.7Spokane County: 62.3 %Spokane County62.3Thurston County: 62.1 %Thurston County62.1Skamania County: 61.9 %Skamania County61.9Walla Walla County: 61.4 %Walla Walla County61.4Clark County: 60.8 %Clark County60.8Grays Harbor County: 59.6 %Grays Harbor County59.6Benton County: 59.4 %Benton County59.4Mason County: 59 %Mason County59Cowlitz County: 58.7 %Cowlitz County58.7Franklin County: 58.6 %Franklin County58.6Chelan County: 58.3 %Chelan County58.3Island County: 58.3 %Island County58.3Klickitat County: 58.3 %Klickitat County58.3Skagit County: 58 %Skagit County58Douglas County: 57.8 %Douglas County57.8Lewis County: 57.7 %Lewis County57.7Asotin County: 57.6 %Asotin County57.6Yakima County: 57.5 %Yakima County57.5Ferry County: 57.5 %Ferry County57.5Grant County: 57.1 %Grant County57.1Stevens County: 56.6 %Stevens County56.6Okanogan County: 56.1 %Okanogan County56.1Pend Oreille County: 55.9 %Pend Oreille County55.9San Juan County: 55.3 %San Juan County55.3Adams County: 55.2 %Adams County55.2Garfield County: 55 %Garfield County55Columbia County: 54.8 %Columbia County54.8Clallam County: 54.7 %Clallam County54.7Pacific County: 54.3 %Pacific County54.3Lincoln County: 53.6 %Lincoln County53.6Jefferson County: 53.1 %Jefferson County53.1Wahkiakum County: 52.4 %Wahkiakum County52.4
%. Source: Invokely calculation with data from U.S. Census Bureau. Retrieved 2026-10-12.

Full ranking

RankCounties2015 (%)Change on 2014
1Whitman County74.1-0 pts
2King County66.8-0.1 pts
3Kittitas County65.2-0.7 pts
4Snohomish County64.3-0.3 pts
5Whatcom County63.6-0.3 pts
6Pierce County63.3-0.2 pts
7Kitsap County62.7-0.2 pts
8Spokane County62.3-0.4 pts
9Thurston County62.1-0.4 pts
10Skamania County61.9-0 pts
11Walla Walla County61.4-0.1 pts
12Clark County60.8-0.2 pts
13Grays Harbor County59.6-0.5 pts
14Benton County59.4-0.4 pts
15Mason County59-0.7 pts
16Cowlitz County58.7-0.3 pts
17Franklin County58.6-0 pts
18Chelan County58.3-0.3 pts
19Island County58.3-0.3 pts
20Klickitat County58.3-0.4 pts
21Skagit County58-0.5 pts
22Douglas County57.8-0.4 pts
23Lewis County57.7-0.5 pts
24Asotin County57.6-0.2 pts
25Yakima County57.5-0.1 pts
26Ferry County57.5-0.6 pts
27Grant County57.1-0.3 pts
28Stevens County56.6-0.5 pts
29Okanogan County56.1-0.6 pts
30Pend Oreille County55.9-0.9 pts
31San Juan County55.3-0.7 pts
32Adams County55.2+0.2 pts
33Garfield County55-0.7 pts
34Columbia County54.8-0.2 pts
35Clallam County54.7-0.5 pts
36Pacific County54.3-0.3 pts
37Lincoln County53.6-1 pts
38Jefferson County53.1-1.3 pts
39Wahkiakum County52.4-0.6 pts

Other periods

About this ranking

Residents aged 18 to 64 as a percentage of total population on 1 July. United States: Census Bureau county population estimates by age; states and the nation are sums of their counties.

Not comparable with working-age shares for ages 15 to 64 used in EU and World Bank statistics.

Every value in the ranking comes from the same publisher and the same period, so the counties are compared on one definition. Equal values share a rank.

How to cite

U.S. Census Bureau. Population Estimates Program, county population by age and sex: residents aged 18 to 64 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties. https://www.census.gov/programs-surveys/popest/data/data-sets.html. Retrieved 2026-10-12.

Citation styles

The publisher is the author. Invokely is named only as the place the figures were read, where a style asks for it.

APA 7

U.S. Census Bureau. (2026). Population Estimates Program, county population by age and sex: residents aged 18 to 64 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties (Counties in Washington by population aged 18 to 64, 2015) [Data set]. Retrieved October 12, 2026, from https://www.census.gov/programs-surveys/popest/data/data-sets.html

MLA 9

Population Estimates Program, county population by age and sex: residents aged 18 to 64 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties, Counties in Washington by population aged 18 to 64, 2015. U.S. Census Bureau, 25 June 2026, https://www.census.gov/programs-surveys/popest/data/data-sets.html. Invokely, https://invokely.ai/rankings/population-18-64/washington-counties?period=2015. Accessed 12 Oct. 2026.

Chicago (author-date)

U.S. Census Bureau. 2026. Population Estimates Program, county population by age and sex: residents aged 18 to 64 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties. Counties in Washington by population aged 18 to 64, 2015. Dataset. Accessed October 12, 2026. https://www.census.gov/programs-surveys/popest/data/data-sets.html. Also distributed by Invokely, https://invokely.ai/rankings/population-18-64/washington-counties?period=2015.

Harvard

U.S. Census Bureau (2026) Population Estimates Program, county population by age and sex: residents aged 18 to 64 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties, Counties in Washington by population aged 18 to 64, 2015 [Dataset]. Available at: https://www.census.gov/programs-surveys/popest/data/data-sets.html, via Invokely: https://invokely.ai/rankings/population-18-64/washington-counties?period=2015 (Accessed: 12 October 2026).

BibTeX
@misc{census_counties_in_washington_by_2015,
  author = {{U.S. Census Bureau}},
  title = {{Population Estimates Program, county population by age and sex: residents aged 18 to 64 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties: Counties in Washington by population aged 18 to 64, 2015}},
  year = {2026},
  howpublished = {Data set},
  url = {https://www.census.gov/programs-surveys/popest/data/data-sets.html},
  urldate = {2026-10-12},
  note = {Accessed via Invokely, https://invokely.ai/rankings/population-18-64/washington-counties?period=2015. Publisher attribution: U.S. Census Bureau. Population Estimates Program, county population by age and sex: residents aged 18 to 64 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties. https://www.census.gov/programs-surveys/popest/data/data-sets.html. Retrieved 2026-10-12.},
}
RIS
TY  - DATA
AU  - U.S. Census Bureau
TI  - Population Estimates Program, county population by age and sex: residents aged 18 to 64 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties: Counties in Washington by population aged 18 to 64, 2015
PY  - 2026
DA  - 2026/06/25
PB  - U.S. Census Bureau
DB  - Invokely
UR  - https://www.census.gov/programs-surveys/popest/data/data-sets.html
L2  - https://invokely.ai/rankings/population-18-64/washington-counties?period=2015
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/population-18-64/washington-counties?period=2015.
N1  - Publisher attribution: U.S. Census Bureau. Population Estimates Program, county population by age and sex: residents aged 18 to 64 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties. https://www.census.gov/programs-surveys/popest/data/data-sets.html. Retrieved 2026-10-12.
ER  -
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Questions

Which county has the highest population aged 18 to 64?

Whitman County, with 74.1% in 2015, according to the U.S. Census Bureau.

Which county has the lowest population aged 18 to 64?

Wahkiakum County, with 52.4% in 2015.

Where does this ranking come from?

Every value comes from one source and one period, so the places are comparable: U.S. Census Bureau, Population Estimates Program, county population by age and sex: residents aged 18 to 64 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties. Retrieved 2026-10-12.

Population aged 18 to 64: other rankings

Counties in Washington: more rankings