The disk of the Milky Way beyond the solar circle is not open to simple
interpretations. In short, it is a mess. From observations of interstellar
gas it is clear that the disk has both a warp and a flare.
The stellar component is riddled with stellar over-densities and/or streams,
the largest of which is the Monoceros stream. It is unclear whether gas
is in-falling and still building the outer disk, whether the distribution
of dark matter inflates the outer disk, if interactions with satellite
galaxies are perturbing the disk or if disrupted satellites are adding
to the disk. It is possible that all of these effects are contributing.
What is clear is that the outer disk of the Galaxy holds many clues as to
how galaxies form and evolve.

   Studying stellar populations in the outer disk is useful but currently has
limitations because spatial and kinematic distributions are not uniquely
described by the various Galactic models. I will discuss our current
attempts at helping to constrain properties of the outer disk using
spectroscopic analysis of A-star samples. Most of the talk will be dedicated
to our analysis of chemically peculiar A-stars in the SDSS DR8 sample and
whether the distribution of these stars indicate that the Monoceros stream
contains ancient blue stragglers or younger A-stars. The latter conclusion
might suggest that the stream is a component of disk of the Galaxy, while the
former might indicate dwarf disruption. I will conclude the talk by showing
our current work on the Canis Major Over-density and our future goal to explore
dust distribution in the disk using A-stars