List of lakes of Washington (state)
Name County ( s ) Total storage ( acre feet ) Surface area ( acres ) Outflow
Franklin D. Roosevelt Lake Douglas , Ferry , Stevens , Lincoln , Grant , Okanogan 9,386,000 79,400 Columbia River
Lake Umatilla Klickitat , Sherman ( OR ) , Gilliam ( OR ) , Morrow ( OR ) , Benton , Umatilla ( OR ) 48,738 Columbia River
Riffe Lake Lewis 1,686,300 11,830 Cowlitz River
Alder Lake Pierce , Thurston 3065 Nisqually River
Ross Lake Whatcom , British Columbia 1,435,000 11,700 Skagit River
Lake Wallula Benton , Walla Walla , Umatilla ( OR ) 1,350,000 42,500 Columbia River
Banks Lake Grant , Douglas 1,275,000 26,877
Swift Reservoir Skamania 755,600 4,585 Lewis River
Wanapum Lake Kittitas , Grant 669,700 14,590 Columbia River
Rufus Woods Lake Douglas , Chelan 590,199 7,800 Columbia River
Lake Herbert G. West Walla Walla , Columbia , Whitman , Franklin 432,000 6,590 Snake River
Merwin Lake Clark , Cowlitz 416,000 3,836 Lewis River
Yale Lake Clark , Cowlitz 401,760 3,612 Lewis River
Potholes Reservoir Grant 332,200 27,800
Reservoirs
This is a list of natural lakes and reservoirs located fully or partially in the U.S. state of Washington . Natural lakes that have been altered with a dam, such as Lake Chelan, are included as lakes, not reservoirs.