Snohomish County AssessorThis data set is a compilation of municipal annexation boundaries for cities in Snohomish County, Washington. The boundaries were compiled from legal descriptions for each annexation from the original incorporation onward. Legal descriptions were interpreted without assumption of intent or bias from any pre-existing maps. Spatial registration conforms to features in the Snohomish County parcel data set. Information captured include the boundary of each individual annexation, the effective date of the annexation and the reference to the insturment authorizing the annexation.ArcGIS FeatureLayerhttps://hub.arcgis.com/datasets/d5fdf58b714c4e4e8494bdaf677d0260_0engSnohomish County Open Data PortalPublicMunicipal Annexations [Washington (State)--Snohomish County]Web servicesWashington (State)--Snohomish CountyWashington (State)Last Modified: 2025-12-04