This dataset updates the Wigington et al. (2013) hydrologic landscape (HL) approach for Oregon to make it more broadly applicable and applies the revised approach to the Pacific Northwest (PNW; i.e., Oregon, Washington, and Idaho). Specific changes incorporated are the use of assessment units based on National Hydrography Dataset Plus V2 catchments, a modified snowmelt model validated over a broader area, an aquifer permeability index that does not require preexisting aquifer permeability maps, and aquifer and soil permeability classes based on uniform criteria. Polygon features in this dataset were created by aggregating (dissolving boundaries between) adjacent, similarly-coded hydrologic assessment units.