  We report on the RXTE detection of a sudden increase in the absorption column
density, $N_\mathrm{H}$, during the 2011 May outburst of GX 304-1. The
$N_\mathrm{H}$ increased up to ${\sim}16\times 10^{22}$ atoms cm$^{-2}$, which
is a factor of 3-4 larger than what is usually measured during the outbursts of
GX 304-1 as covered by RXTE. Additionally, an increase in the variability of
the hardness ratio as calculated from the energy resolved RXTE-PCA light curves
is measured during this time range. We interpret these facts as an occultation
event of the neutron star by material in the line of sight. Using a simple 3D
model of an inclined and precessing Be disk around the Be type companion, we
are able to qualitatively explain the $N_\mathrm{H}$ evolution over time. We
are able to constrain the Be-disk density to be on the order of $10^{-11}$ g
cm$^{-3}$. Our model strengthens the idea of inclined Be disks as origin of
double-peaked outbursts as the derived geometry allows accretion twice per
orbit under certain conditions.
