  We present photometric metallicity measurements for a sample of 2.6 million
bulge red clump stars extracted from the Blanco DECam Bulge Survey (BDBS).
Similar to previous studies, we find that the bulge exhibits a strong vertical
metallicity gradient, and that at least two peaks in the metallicity
distribution functions appear at b < -5. We can discern a metal-poor ([Fe/H] ~
-0.3) and metal-rich ([Fe/H] ~ +0.2) abundance distribution that each show
clear systematic trends with latitude, and may be best understood by changes in
the bulge's star formation/enrichment processes. Both groups exhibit asymmetric
tails, and as a result we argue that the proximity of a star to either peak in
[Fe/H] space is not necessarily an affirmation of group membership. The
metal-poor peak shifts to lower [Fe/H] values at larger distances from the
plane while the metal-rich tail truncates. Close to the plane, the metal-rich
tail appears broader along the minor axis than in off-axis fields. We also
posit that the bulge has two metal-poor populations -- one that belongs to the
metal-poor tail of the low latitude and predominantly metal-rich group, and
another belonging to the metal-poor group that dominates in the outer bulge. We
detect the X-shape structure in fields with |Z| > 0.7 kpc and for stars with
[Fe/H] > -0.5. Stars with [Fe/H] < -0.5 may form a spheroidal or "thick bar"
distribution while those with [Fe/H] > -0.1 are strongly concentrated near the
plane.
