Example of how clouds in Table A.1 are assigned to known structures and spiral arms. The black line with the blue shaded uncertainties are our density predictions as a function of distance for a given LOS, and the purple vertical lines are all probable distance estimates from the BESSEL survey (Reid et al. 2016) for the same LOS with velocities observed in Dame et al. (1986) (e.g. Aquila rift, Sagittarius Near, and Perseus here). The dashed red line indicates our threshold for selecting statistically significant clouds. If there is a match, such as the near Sagittarius Arm in the middle, we assign the cloud to that particular structure. The LOS’ galactic longitude and latitude are shown in the top right corner.