  The absorption of cosmic rays by the sun produces a shadow at the earth. The
angular offset and broadening of the shadow are determined by the magnitude and
structure of the interplanetary magnetic field (IPMF) in the inner solar
system. We report the first measurement of the solar cosmic ray shadow by
detection of deep underground muon flux in observations made during the entire
ten-year interval 1989 to 1998. The sun shadow varies significantly during this
time, with a $3.3\sigma$ shadow observed during the years 1995 to 1998.
