Major ecoregions of Washington state

 Washington State Department of Ecology

Source: Draft: Level III and IV Ecoregions of the Northwestern United States (U.S. Environmental Protection Agency,Acrobat pdf, 2944 kilobytes, metadata). Also see Level III ecoregions of the continental United States. 

 
    1  Coast Range
    1a  Coastal Lowlands
    1b  Coastal Uplands
    1c  Low Olympics
    1d  Volcanics
    1e  Outwash
    1f  Willapa Hills
    1g  Mid-Coastal Sedimentary
    1h  Southern Oregon Coastal Mountains
    1i  Redwood Zone
     
    2  Puget Lowland
    2a  Fraser Lowland
    2b  Eastern Puget Riverine Lowlands
    2c  San Juan Islands
    2d  Olympic Rainshadow
    2e  Eastern Puget Uplands
    2f  Central Puget Lowland
    2g  Southern Puget Prairies
    2h  Cowlitz/Chehalis Foothills
    2i  Cowlitz/Newaukum Prairie Floodplains
     
    3 Willamette Valley
    3a  Portland/Vancouver Basin
    3b  Willamette River and Tributaries Gallery Forest
    3c  Prairie Terraces
    3d  Valley Foothills
     
    4 Cascades
    4a  Western Cascades Lowlands and Valleys
    4b  Western Cascades Montane Highlands
    4c  Cascade Crest Montane Forest
    4d  Cascade Subalpine/Alpine
    4e  High Southern Cascades Montane Forest
    4f  Southern Cascades
     
    9 Eastern Cascade Slope and Foothills
    9a  Yakima Plateau & Slopes
    9b  Grand Fir Mixed Forest
    9c  Oak/Conifer Eastern Cascades-Columbia Foothills
    9d  Ponderosa Pine/Bitterbrush Woodland
    9e  Pumice Plateau Forest
    9f  Cold Wet Pumice Plateau Basins
    9g  Klamath/Goose Lake Warm Wet Basins
    9h  Fremont Pine/Fir Forest
    9i  Southern Cascade Slope
    9j  Klamath Juniper/Ponderosa Pine Woodland
     
    10  Columbia Plateau
    10a  Channeled Scablands
    10b  Loess Islands
    10c  Umatilla Plateau
    10d  Okanogan Drift Hills
    10e  Pleistocene Lake Basins
    10f  Dissected Loess Uplands
    10g  Yakima Folds
    10h  Palouse Hills
    10i  Deep Loess Foothills
    10j  Nez Perce Prairie
    10k  Deschutes/John Day Canyons
    10l  Lower Snake and Clearwater Canyons
    10m  Okanogan Valley
     
    11 Blue Mountains
    11a  John Day/Clarno Uplands
    11b  John Day/ Clarno Highlands
    11c  Maritime-Influenced Zone
    11d  Melange
    11e  Wallowas/Seven Devils Mountains
    11f  Canyons and Dissected Highlands
    11g  Canyons and Dissected Uplands
    11h  Continental Zone Highlands
    11i  Continental Zone Foothills
    11k  Blue Mountain Basins
    11l  Mesic Forest Zone
    11m  Subalpine-Alpine Zone
    11n  Deschutes River Valley
    11o  Cold Basins
     
    15 Northern Rockies
    15a  Grave Creek Range-Nine Mile Divide
    15b  Camas Valley
    15c  Flathead Valley
    15d  Tobacco Plains
    15e  Flathead Hills and Mountains
    15f  Grassy Potlatch Ridges
    15g  Western Okanogan Semiarid Foothills
    15h  High Northern Rockies
    15i  Clearwater Mountains and Breaks
    15j  Lower Clearwater Canyons
    15k  Clark Fork Valley and Mountains
    15l  Salish Mountains
    15m  Kootenai Valley
    15n  Weippe Prairie
    15o  Coeur d'Alene Metasedimentary Zone
    15p  St. Joe Schist-Gneiss Zone
    15q  Purcell-Cabinet-North Bitterroot Mountains
    15r  Okanogan-Colville Xeric Valleys and Foothills
    15s  Spokane Valley Outwash Plains
    15t  Stillwater-Swan Wooded Valley
    15u  Inland Maritime Foothills and Valleys
    15v  Northern Idaho Hills and Low Relief Mountains
    15w  Western Selkirk Maritime Forest
    15x  Okanogan Highland Dry Forest
    15y  Granitic Selkirk Mountains

    77 North Cascades
    77a  North Cascades Lowland Forests
    77b  North Cascades Highland Forests
    77c  North Cascades Subalpine/Alpine
    77d  Pasayten/Sawtooth Highlands
    77e  Okanogan Pine/Fir Hills
    77f  Chelan Tephra Hills
    77g  Wenatchee/Chelan Highlands
    77h  Chiwaukum Hills and Lowlands
    77i  High Olympics