Washington State Department of EcologyThe Washington State Department of Ecology has four regions covering the state: Eastern, Central, Northwest, and Southwest. Boundaries between the regions follow county boundaries. Regional offices are located in Spokane (Eastern), Yakima (Central), Bellevue (Northwest), and Olympia (Southwest).ArcGIS FeatureLayerhttps://hub.arcgis.com/datasets/61f7f6751185407383160cb00ca6937f_6engState of Washington Geospatial Open Data PortalPublicDepartment of Ecology Regions [Washington (State)]Web servicesWashington (State)Last Modified: 2025-12-29