Map of the average A_V measured for M-type stars across the region. Each of the 2500 2.4′ × 2.4′ boxes that constitute the map is colored according to the mean A_V computed across the population of M-type stars projected onto that box. The reference color–A_V scale used is shown in the side axis. Colors are assigned only to boxes containing at least two M-stars in our sample, and with an internal spread in A_V that is no more than 3σ larger than the typical dispersion in A_V measured among boxes containing the same number of sources within the map.