Snow density in the western United States mountains was studied using data collected by the NRCS. The analysis showed that snowpack density changes less than snow depth and water equivalent from year to year. Snow density and densification rates vary by location, with densification increasing by 2.0 kg m−3 day−1 in March. Cluster analysis revealed four distinct density and densification rate patterns, with proximity to large water bodies being a key factor. In mountain ranges, snowpack density is mainly influenced by elevation.