Program: GS-2011A-C-9

NASA's Wide-field Infrared Survey Explorer (WISE), completed its first coverage of the entire sky at 3.4, 4.6, 12 and $22\mu$m (W1, W2, W3, and W4) in July 2010, reaching sensitivities hundreds of times deeper than IRAS. We have obtained spectroscopy of more than 50 WISE sources with a broad range of colors, and have found 14 with $z > 1.8$. These sources have in excess of $10^{13}$ solar luminosities, and possibly $10^{15}$. Ten were selected by requiring strong W4 detection combined with faint or insignificant W1 and W2 detections: W1W2drops. Most W1W2drops have $z > 1.8$, making them the best available sample for finding extreme dusty ULIRGs with WISE. We request NOAO time, combined with other facilities, to obtain redshifts and optical and near IR photometry of the complete all-sky sample of 234 W12drops. The resulting SEDs will enable us to extend the obscurations, luminosities, and star formation rates associated with ultra-luminous infrared galaxies (ULIRGs) into uncharted terrain.