Secrets of the "Greatest Snow on Earth"

State license plates and tourism brochures boast that Utah ski areas receive the “Greatest Snow on Earth”, but is there really anything special about Utah's snow? Often it is argued in ski industry brochures that Utah's snow is the "greatest" because it is the “driest” (i.e., has a low density or water content), yet the mean water content of snow at Alta ski area, which is world-renowned for powder skiing and provides the cornerstone for Utah's famous slogan, is not lower than observed, for example, at many Colorado and Wyoming ski resorts. Based on a 25+ year climatology of daily snowfall and snow density, we propose that Alta's reputation is not based solely on mean water content, but also abundant natural snowfall. Although it cannot be shown that Utah's snow is the “Greatest on Earth”, the climatology at Alta and other nearby ski areas is consistent with an especially high frequency of deep-powder days compared with other ski resorts in North America.