| Rank |
County |
Land Area |
| 1 |
Okanogan County, Washington
|
5,268.0
|
| 2 |
Yakima County, Washington
|
4,295.4
|
| 3 |
Chelan County, Washington
|
2,920.5
|
| 4 |
Grant County, Washington
|
2,679.5
|
| 5 |
Stevens County, Washington
|
2,477.8
|
| 6 |
Lewis County, Washington
|
2,402.8
|
| 7 |
Lincoln County, Washington
|
2,310.5
|
| 8 |
Kittitas County, Washington
|
2,297.3
|
| 9 |
Ferry County, Washington
|
2,203.2
|
| 10 |
Whitman County, Washington
|
2,159.1
|
| 11 |
King County, Washington
|
2,115.6
|
| 12 |
Whatcom County, Washington
|
2,106.9
|
| 13 |
Snohomish County, Washington
|
2,087.3
|
| 14 |
Adams County, Washington
|
1,925.0
|
| 15 |
Grays Harbor County, Washington
|
1,902.0
|
| 16 |
Klickitat County, Washington
|
1,871.3
|
| 17 |
Douglas County, Washington
|
1,819.3
|
| 18 |
Jefferson County, Washington
|
1,803.7
|
| 19 |
Spokane County, Washington
|
1,763.8
|
| 20 |
Clallam County, Washington
|
1,738.3
|
| 21 |
Skagit County, Washington
|
1,731.2
|
| 22 |
Benton County, Washington
|
1,700.4
|
| 23 |
Pierce County, Washington
|
1,669.5
|
| 24 |
Skamania County, Washington
|
1,655.7
|
| 25 |
Pend Oreille County, Washington
|
1,400.0
|
| 26 |
Walla Walla County, Washington
|
1,270.1
|
| 27 |
Franklin County, Washington
|
1,242.2
|
| 28 |
Cowlitz County, Washington
|
1,140.1
|
| 29 |
Mason County, Washington
|
959.4
|
| 30 |
Pacific County, Washington
|
932.7
|
| 31 |
Columbia County, Washington
|
868.6
|
| 32 |
Thurston County, Washington
|
722.0
|
| 33 |
Garfield County, Washington
|
710.7
|
| 34 |
Asotin County, Washington
|
636.2
|
| 35 |
Clark County, Washington
|
629
|
| 36 |
Kitsap County, Washington
|
394.9
|
| 37 |
Wahkiakum County, Washington
|
263.4
|
| 38 |
Island County, Washington
|
208.4
|
| 39 |
San Juan County, Washington
|
173.9
|