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We present optical spectra of the host galaxies of the short-durationgamma-ray burst GRB 070429B and the likely short-duration with extendedemission GRB 070714B. In both cases, we find a single emission line that weidentify as O II lambda 3727 at z ~ 0.9. Both events are more distant than anyprevious short-duration GRB with a secure host association from thesub-arcsecond position of an optical afterglow. GRBs 070429B and 070714Bprovide strong evidence in support of our previous claims in Berger et al. thata significant fraction of short-duration hosts (>~ 33%) reside at z > 0.7. Wediscuss the implications of the existence this population on the energetics ofshort-duration GRBs, as well as on progenitor models. In the context of thedegenerate binary merger scenario, such events require progenitor systems witha range of lifetimes and disfavor progenitor models with a long, narrowlifetime distribution.

GRBs 070429B and 070714B: The High End of the Short-Duration Gamma-Ray Burst Redshift Distribution