SGR SNOW HISTORY Snowfall year-by-year (movie) Snow data are from the Snotel Summit Ranch recording station on Rock Creek. At this station, snow is weighed on a 'snow pillow' and data are converted to equivalent inches of water (SWE=Snow Water Equivalent). Snow accumulation each winter starting October 1. The rise is remarkably linear (about 0.07 inches of water per day starting early November). Maximum depth occurs about April 10.