| County | FIPS |
|---|---|
| Adams County | 53001 |
| Asotin County | 53003 |
| Benton County | 53005 |
| Chelan County | 53007 |
| Clallam County | 53009 |
| Clark County | 53011 |
| Columbia County | 53013 |
| Cowlitz County | 53015 |
| Douglas County | 53017 |
| Ferry County | 53019 |
| Franklin County | 53021 |
| Garfield County | 53023 |
| Grant County | 53025 |
| Grays Harbor County | 53027 |
| Island County | 53029 |
| Jefferson County | 53031 |
| King County | 53033 |
| Kitsap County | 53035 |
| Kittitas County | 53037 |
| Klickitat County | 53039 |
| Lewis County | 53041 |
| Lincoln County | 53043 |
| Mason County | 53045 |
| Okanogan County | 53047 |
| Pacific County | 53049 |
| Pend Oreille County | 53051 |
| Pierce County | 53053 |
| San Juan County | 53055 |
| Skagit County | 53057 |
| Skamania County | 53059 |
| Snohomish County | 53061 |
| Spokane County | 53063 |
| Stevens County | 53065 |
| Thurston County | 53067 |
| Wahkiakum County | 53069 |
| Walla Walla County | 53071 |
| Whatcom County | 53073 |
| Whitman County | 53075 |
| Yakima County | 53077 |