Heliocentric distance as a function of absolute r magnitude for our final data set (upper panel) and for the MG10 data set (lower panel). CN-normal stars are plotted as small dots, while CN-strong stars are shown as filled stars. Only a randomly selected 25% of the CN-normal MG10 stars is shown to reduce crowding. In both panels, the lower boundary is set by the bright limit of the SEGUE survey (g = 14), and the upper boundary is set by our requirement that SN_blue > 15.