This is accompanying data produced for the study "Implications of Model Selection: Inter-Comparison of Publicly-Available, CONUS-Extent Hydrologic Component Estimates". These datasets were converted from their primary structures (rasters and shapefiles) to EPA Ecoregions Level I. Conversion was performed by averaging timestep layers via mean area weight to produce a single vector of monthly values for each ecoregion, for each of the following hydrologic cycle components: precipitation (P), actual evapotranspiration (AET), runoff (R), snow water equivalent (SWE), rootzone soil moisture in equivalent water depth (RZSME), and rootzone soil moisture in volumetric water content (RZSMV).