  We point out that if heavy metastable particles composing the dark matter of
our galaxy are responsible for the ultra-high energy cosmic rays (UHECR) then
the leading tidal stream of the Sagittarius dwarf galaxy could be detected
through UHECR. The signal would be an anisotropy in the UHECR flux smaller than
the telltale anisotropy towards the galactic center that would first establish
unstable dark matter as the origin of the UHECR.
