  We report on the detection in Sloan Digital Sky Survey data of at least
three, roughly parallel components in a 65 degree-long stellar stream complex
previously identified with the Anticenter or Monoceros Ring. The three-stream
complex varies in width from 4 to 6 degrees along its length and appears to be
made up of two or more narrow substreams as well as a broader, diffuse
component. The width and complexity of the stream indicate that the progenitor
was likely a dwarf galaxy of significant size and mass. The stream is 8.9 kpc
distant and is oriented almost perpendicularly to our line of sight. The
visible portion of the stream does not pass near any known dwarf galaxies and a
preliminary orbit does not point to any viable progenitor candidates. Orbits
for the narrower substreams can be modeled with velocity offsets from the broad
component of about 8 km/s. We suggest that the broad component is likely to be
the remains of a dwarf galaxy, while the narrower streams constitute the
remnants of dynamically distinct components which may have included a native
population of globular clusters. While the color of the main sequence turn-off
is not unlike that for the Monoceros Ring, neither the visible stream nor any
reasonable projection of its orbit passes through Monoceros or Canis Major, and
we conclude that this stream is probably unrelated to the overdensities found
in these regions.
