A MATURE DUSTY STAR-FORMING GALAXY HOSTING GRB 080607 AT z = 3.036**Based in part on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

We report the discovery of the host galaxy of Swift dark burst GRB 080607 at zGRB = 3.036. GRB 080607 is a unique case of a highly extinguished (AV ≈ 3 mag) afterglow that was yet sufficiently bright for high-quality absorption-line spectroscopy. The host galaxy is clearly resolved in deep Hubble Space Telescope (HST) WF3/IR F160W images and well detected in the Spitzer IRAC 3.5 μm and 4.5 μm channels, while displaying little/no fluxes in deep …