  Measurements in very low disorder two-dimensional electrons confined to
relatively wide GaAs quantum well samples with tunable density reveal reentrant
$\nu=1$ integer quantum Hall states in the lowest Landau level near filling
factors $\nu=4/5$ and 6/5. These states are not seen at low densities and
become more prominent with increasing density and in wider wells. Our data
suggest a close competition between different types of Wigner crystal states
near these fillings. We also observe an intriguing disappearance and
reemergence of the $\nu=4/5$ fractional quantum Hall effect with increasing
density.
