Jenifer Parsons, EcologyWatersheds where populations of the New Zealand mudsnail (Potamopyrgus antipodarum) have been found or are likely to be found due to proximity to known populations. Based on HUC12 WBD Watersheds from USGS.ArcGIS FeatureLayerhttps://hub.arcgis.com/datasets/0b4f24486568408fa2790b31216cc6ff_6engState of Washington Geospatial Open Data PortalPublicInvasive Species Areas of Extreme Concern: Watersheds [Washington (State)]Web servicesWashington (State)Last Modified: 2025-12-29