  We report on optical spectroscopic observations of the X-ray Transient XTE
J1118+480 covering the period from April 7, 2000 to July 4, 2000. The spectrum
is characterized by weak, broad, double-peaked Balmer and He lines on top of a
blue continuum of slope p ~ 1/3, as expected for an optically-thick accretion
disk. The weak Bowen blend seen in our spectra may indicate a low intrinsic
metallicity for the source. The presence of a partial S-wave pattern in the
HeII lambda-4686 line appears consistent with the reported photometric orbital
period Porb = 4.1 hr for XTE J1118+480. By using a combination of Doppler
mapping and various theoretical arguments, we constrain plausible orbital
parameters for the system: a mass ratio 0.02 <~ q <~ 0.1, an inclination i >~
70 deg for a neutron star primary, or 30 deg <~ i <~ 50 deg for a black hole
primary with a mass between 4 and 10 Msun. CaII absorption features observed at
very high resolution constrain the interstellar hydrogen absorption column
log[N_HI (cm^{-2})] ~ 20.45 +/- 0.2 and the identification of three absorbing
clouds indicate a distance to the source <~ 1 kpc, assuming the line-of-sight
to XTE J1118+480 has average high-latitude properties. These results are
discussed in the context of previous multiwavelength observations of this
unusual system.
