Overview: This project represented a partnership between US Geological Survey (USGS) National Geospatial Program, the US Fish and Wildlife Service (on behalf of the Desert Landscape Conservation Cooperative (DLCC)), and the Center for Geographical Studies (CGS) at California State University, Northridge (CSUN). The project focused on updates and improvements to the high resolution National Hydrography Dataset (NHD) through the addition and/or improvement of NHD polygon, line, and point features in effort to fully realize a more robust and accurate NHD for priority areas within the DLCC geography. The work performed was designed to support the science objectives for the DLCC and its partners through the use of an updated NHD. The work will provide an important framework basis for the development of hydrologic models required to address effects of climate change. Additionally, several other DLCC objectives and needs will be supported by this work, which include: biological modeling, storm impacts on flow, and conservation planning. This effort also directly supported and advanced the USGS’ efforts related to the improvement of the NHD and its delivery to the public via The National Map. Finally, it also facilitated an additional agreement with the US Forest Service (USFS) for continued NHD improvement work in Arizona and beyond.