  We present an analysis of a new, large sample of field blue-straggler stars
(BSSs) in the thick disk and halo system of the Galaxy, based on stellar
spectra obtained during the Sloan Digital Sky Survey (SDSS) and the Sloan
Extension for Galactic Understanding and Exploration (SEGUE). Using estimates
of stellar atmospheric parameters obtained from application of the SEGUE
Stellar Parameter Pipeline, we obtain a sample of some 8000 BSSs, which are
considered along with a previously selected sample of some 4800 blue
horizontal-branch (BHB) stars. We derive the ratio of BSSs to BHB stars,
F$_{\rm BSS/BHB}$, as a function of Galactocentric distance and distance from
the Galactic plane. The maximum value found for F$_{\rm BSS/BHB}$ is $\sim~$4.0
in the thick disk (at 3 kpc $<$ $|$Z$|$ $<$ 4 kpc), declining to on the order
of $\sim~1.5-2.0$ in the inner-halo region; this ratio continues to decline to
$\sim~$1.0 in the outer-halo region. We associate a minority of field BSSs with
a likely extragalactic origin; at least 5$\%$ of the BSS sample exhibit radial
velocities, positions, and distances commensurate with membership in the
Sagittarius Stream.
