U.S. Fish and Wildlife Service Natural Resource Program CenterThis dataset represents the region of hydrological influence (RHI) for National Wildlife Refuge System lands. RHI is defined as the area that is most likely influencing the hydrology and water quality encompassing the refuge. Many of these boundaries are merged USGS unique hydrologic units (e.g., HUC-6, 8, 10, 12) or generated using hydrologic modeling techniques. Please see the ‘Comment' field for more information. Data Set Contact: U.S. Fish and Wildlife Service Natural Resource Program Center, GIS Team Lead, richard_easterbrook@fws.govArcGIS FeatureLayerhttps://hub.arcgis.com/datasets/4acbb1423e8a472c905989a77c6d6d9c_0engU.S. Fish and Wildlife Service Open DataPublicFWS HQ NWRS Region Hydrological Influence [United States]Web servicesUnited StatesLast Modified: 2021-07-20