These data were compiled by the StreamNet partnership and were last updated on January 30, 2019. Generalized fish distribution represents current presence and habitat use by species and run timing (for anadromous fish) and is based on a combination of field data and the best professional judgement of local fish biologists, in the Pacific Northwest Region (Oregon, Washington, Idaho and Montana). These data were collected by biologists at the state fish & wildlife agencies of Washington (WDFW), Oregon (ODFW), Idaho (IDFG) and Montana (MFWP). These data were submitted to the StreamNet regional staff at Pacific States Marine Fisheries Commision (PSMFC) where the regionally consistent distribution feature class is maintained and published online. These and related spatial data are for download from http://www.streamnet.org/data/interactive-maps-and-gis-data/