We describe first results of a spectroscopic probe of selected fields from the Grid Giant Star Survey .
Multifiber spectroscopy of several hundred stars in a strip of eleven fields along \delta \approx - 17 ^ { \circ } , in the range 12 \lesssim \alpha \lesssim 17 hours , reveals a group of 8 giants that have kinematical characteristics differing from the main field population , but that as a group maintain coherent , smoothly varying distances and radial velocities with position across the fields .
Moreover , these stars have roughly the same abundance , according to their MgH+Mgb absorption line strengths .
Photometric parallaxes place these stars in a semi-loop structure , arcing in a contiguous distribution between 5.7 and 7.9 kpc from the Galactic center .
The spatial , kinematical , and abundance coherence of these stars suggests that they are part of a diffuse stream of tidal debris , and one roughly consistent with a wrapped , leading tidal arm of the Sagittarius dwarf spheroidal galaxy .