We use velocity and metallicity information from SDSS and SEGUE stellar spectroscopy to fit an orbit to the narrow 63 ^ { \circ } stellar stream of Grillmair and Dionatos .
The stars in the stream have a retrograde orbit with eccentricity e = 0.33 ( perigalacticon of 14.4 kpc and apogalacticon of 28.7 kpc ) and inclination approximately i \sim 35 ^ { \circ } .
In the region of the orbit which is detected , it has a distance of about 7 to 11 kpc from the Sun .
Assuming a standard disk plus bulge and logarithmic halo potential for the Milky Way stars plus dark matter , the stream stars are moving with a large space velocity of approximately 276 ~ { } km~ { } s ^ { -1 } at perigalacticon .
Using this stream alone , we are unable to determine if the dark matter halo is oblate or prolate .
The metallicity of the stream is [ Fe/H ] = -2.1 \pm 0.1 .
Observed proper motions for individual stream members above the main sequence turnoff are consistent with the derived orbit .
None of the known globular clusters in the Milky Way have positions , radial velocities , and metallicities that are consistent with being the progenitor of the GD-1 stream .