This data release includes SnowModel output for three headwater study areas in Colorado at seven spatial resolutions and from two forcing datasets over a 40-year period from water year 1980 to 2019. The resolutions include 30 m, 50 m, 100 m, 150 m, 250 m, 500 m, and 1,000 m. The model was run with a 3-hour temporal resolution from September 1, 1980 to August 31, 2019. Two meteorology forcing datasets were used, including National Land Data Assimilation System-2 at 1/8th degree (about 12 km) resolution data and the Weather Research and Forecasting model data at 4 km resolution. Output variables include snow-water equivalent depth (swed), runoff (roff), air temperature (tair), snow-covered area (sca), snow depth (snod), precipitation (prec), and liquid precipitation (rpre). Additionally, topography and vegetation datasets are included for each combination of unique domain and resolution, as well as the model parameterization file for a representative year. The data are organized by water year (WY) for each forcing type. For example, 'XXXX_wyYYYY.zip', where XXXX is either NLDAS2 or WRFCTL, and YYYY is the water year, with each water year including subdirectories for each of the three headwater study areas ('ER', 'FR', and 'SB' for East River, Fraser River, and Senator Beck, respectively). Each headwater study area subdirectory contains a subdirectory for each spatial resolution ('30', '50', '100', '150', '250', '500', '1000'), and each of those subdirectories contains NetCDF files for the seven variables modeled at that resolution. For example,'SA_RES_VAR_wyYYYY.nc', where SA is one of the three headwater study areas, RES is one of the seven spatial resolutions, VAR is one of the seven output variables, and YYYY is the water year.