| 2952 | Adams | 147 | formed out of Whitman County | 28 | Nov | 1883 | |
| 2953 | Asotin | 147 | created out of Garfield County | 27 | Oct | 1883 | |
| 2954 | Benton | 147 | created out of Klickitat County | 8 | Mar | 1915 | |
| 2955 | Chelan | 147 | created out of Okanogan and Kittias Counties | 13 | Mar | 1899 | |
| 2956 | Clallam | 147 | formed | 16 | Apr | 1854 | |
| 2957 | Clark | 147 | first county for Washington named after exploer William Clark. | 20 | Aug | 1845 | |
| 2958 | Columbia | 147 | created out of Walla Walla County | 11 | Nov | 1875 | |
| 2959 | Cowlitz | 147 | | 21 | Apr | 1854 | |
| 2960 | Douglas | 147 | created out of Lincoln County | 28 | Nov | 1883 | |
| 2961 | Ferry | 147 | created out of Stevens County | 21 | Feb | 1899 | |
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