Abstract. More than 2,300 U.S. snowstorms occurring east of the Rockies were mapped and analyzed during a 51-year period (1950-2000). A snowstorm was defined as an area where three or more adjacent weather stations experienced 6 inches or more snowfall in a 1- or 2-day period. The annual number of snowstorms fluctuated greatly from one year to another, however when examining the longer-term trend a bell-shaped distribution with a peak in the 1970s was found. Snowstorms had three general shapes: circular, elliptical, and irregular, and on average covered 41,300 square miles with an average length of 355 miles. Three regions, the Northeast, the upper Midwest, and the central Great Plains had the highest incidence of snowstorms. Nearly 43% of all storms were influenced by mountains (Rockies or Appalachians), while 33% of all storms were influenced by the Great Lakes. Approximately 15% of all snowstorms had a maximum point snowfall amount of 20 inches or more.