  We present a map of the dust reddening to 4.5 kpc derived from Pan-STARRS1
stellar photometry. The map covers almost the entire sky north of declination
-30 degrees at a resolution of 7' to 14', and is based on the estimated
distances and reddenings to more than 500 million stars. The technique is
designed to map dust in the Galactic plane, where many other techniques are
stymied by the presence of multiple dust clouds at different distances along
each line of sight. This reddening-based dust map agrees closely with the
Schlegel, Finkbeiner, and Davis (SFD; 1998) far-infrared emission-based dust
map away from the Galactic plane, and the most prominent differences between
the two maps stem from known limitations of SFD in the plane. We also compare
the map with Planck, finding likewise good agreement in general at high
latitudes. The use of optical data from Pan-STARRS1 yields reddening
uncertainty as low as 25 mmag E(B-V).
