Snowpack is an important source for water supplies in the western U.S. Because wildfires are increasing in frequency and magnitude, potential reductions in snowpack after wildfires are important for water managers. The objective of this study is to estimate the impact of wildfires and the combined impact of climate change and wildfires on snow water equivalent (SWE) across western U.S. ecoregions. Four metrics of snowpack are evaluated including annual peak SWE, annual peak SWE normalized by winter precipitation, date of peak SWE, and date of melt-out. Random forest (RF) models are developed for the change in each metric using SWE data from burned and unburned SNOTEL sites and topographic, weather, and land cover predictor variables. The RF models are then applied across the ecoregions. In all ecoregions, the median prediction from the model is a decrease in peak SWE due to wildfire, but the distribution of changes within each ecoregion includes both decreases and increases. The median prediction also indicates earlier peak SWE and melt-out dates for all ecoregions except for the Arizona-New Mexico Mountains, and nearly all locations within a given ecoregion are expected to have similar changes to the dates. Terrain slope is an important predictor of changes in peak SWE, and mean temperature is important for changes in the dates of peak SWE and melt-out. The estimated total changes in SWE due to wildfires that occurred from 2015 to 2020 range from a 1% increase in the North Cascades to a 6% reduction in the Arizona-New Mexico Mountains.