  We present a high-resolution, high signal-to-noise optical spectrum of the
afterglow of GRB 051111 obtained with the HIRES spectrograph on the Keck I 10-m
telescope. The spectrum exhibits three redshifted absorption systems with the
highest, at z=1.54948, arising in the GRB host galaxy. While the Ly-alpha
feature is outside the range of our spectrum, the high column density of
weakly-depleted Zn suggests that the host is a damped Lyman-alpha system with
N(HI)>10^21(Z/Z_sun)^-1. The bulk of the gas (>80%) is confined to a narrow
velocity range of |v|<30 km/s exhibiting strong dust depletion of refractory
elements such as Fe and Cr. The depletion pattern is similar to that observed
in warm disk clouds of the Milky Way. We also detect absorption from all
ground-level fine-structure states of FeII, the first such example in a QSO-DLA
or GRB-absorption spectrum, which indicate conditions that are consistent with
the "warm disk" depletion pattern. The absorption profiles of FeII and MgII
extend over several hundred km/s, with a depletion pattern that more closely
resembles that of QSO-DLAs, suggesting that the sight line to GRB 051111 probes
the halo of the host galaxy in addition to the dense disk. Thus, detailed
diagnostics of the interstellar medium of GRB host galaxies continue to provide
insight into regions which are generally missed in quasar surveys.
