  We detect the optical afterglow and host galaxy of GRB 070714B. Our
observations of the afterglow show an initial plateau in the lightcurve for
approximately the first 5 to 25 minutes, then steepening to a powerlaw decay
with index alpha= 0.86 +/- 0.10 for the period between 1 to 24 hours post
burst. This is consistent with the X-ray light-curve which shows an initial
plateau followed by a similar subsequent decay. At late time, we detect a host
galaxy at the location of the optical transient. Gemini Nod & Shuffle
spectroscopic observations of the host show a single emission line at 7167
angstroms which, based on a grizJHK photometric redshift, we conclude is the
3727 angstrom [O II] line. We therefore find a redshift of z=0.923. This
redshift, as well as a subsequent probable spectroscopic redshift determination
of GRB 070429B at z=0.904 by two other groups, significantly exceeds the
previous highest spectroscopically confirmed short burst redshift of z=0.546
for GRB 051221. This dramatically moves back the time at which we know short
bursts were being formed, and suggests that the present evidence for an old
progenitor population may be observationally biased.
