  We present spectroscopic observations of the host galaxy and explosion site
of the long-duration gamma-ray burst GRB 020819. We determine a metallicity for
this host environment of log(O/H) + 12 = 9.0 +/- 0.1, by far the highest
metallicity determined for a long-duration GRB to date. We compare the
metallicity and other properties of the GRB 020819 host environment to existing
observations of long-duration GRB host galaxies, and consider the implications
that this metallicity has for our understanding of long-duration GRB progenitor
scenarios. We also consider how this unusually high metallicity may relate to
the status of GRB 020819 as a "dark" burst, with no detected optical afterglow.
