  We have observed the Galactic black hole transient 4U 1630-47 during the
decay of its 2016 outburst with Chandra and Swift to investigate the properties
of the dust scattering halo created by the source. The scattering halo shows a
structure that includes a bright ring between 80" and 240" surrounding the
source, and a continuous distribution beyond 250". An analysis of the $^{12}$CO
$J=1-0$ map and spectrum in the line of sight to the source indicate that a
molecular cloud with a radial velocity of -79 km s$^{-1}$ (denoted MC -79) is
the main scattering body that creates the bright ring. We found additional
clouds in the line of sight, calculated their kinematic distances and resolved
the well known "near" and "far" distance ambiguity for most of the clouds. At
the favored far distance estimate of MC -79, the modeling of the surface
brightness profile results in a distance to 4U 1630-47 of 11.5 $\pm$ 0.3 kpc.
If MC -79 is at the near distance, then 4U 1630-47 is at 4.7 $\pm$ 0.3 kpc.
Future Chandra, Swift, and sub-mm radio observations not only can resolve this
ambiguity, but also would provide information regarding properties of dust and
distribution of all molecular clouds along the line of sight. Using the results
of this study we also discuss the nature of this source and the reasons for the
anomalously low soft state observation observed during the 2010 decay.
