Histogram of distances of the 45 clouds in the sample in 0.5 kpc bins. The full sample is plotted in the solid gray histogram, the histogram for just the IRDCs is plotted in the green dot-dashed line, and the ISOSS targets are plotted in the red histogram. The median distance of the full sample, 3.2 kpc, is plotted in the solid gray line, and the median for the IRDC-only (3.1 kpc) and ISOSS-only (3.5 kpc) are shown with solid green and red vertical lines.