  We present optical identifications and redshifts for seventeen new
high-redshift radio sources. Fifteen of these sources are radio galaxies; the
remaining two are high-redshift, steep-spectrum, radio-loud quasars. These
objects were discovered as part of an ongoing study of compact (theta < 10
arcsec), moderately steep spectrum (alpha(1.4 GHz;4.8 GHz) > 0.75, S(nu) ~
nu^(-alpha)) sources from the MIT-Green Bank (MG) radio catalog (S(5 GHz) > 50
mJy). Spectra for the optical counterparts were obtained at the W.M. Keck
Telescopes and are among the optically faintest radio galaxies thus far
identified. Redshifts range between 0.3 and 3.6, with thirteen of the seventeen
at redshifts greater than 1.5. Combining these new radio galaxies with two
published MG radio galaxy spectra, we synthesize a composite MG radio galaxy
spectrum and discuss the properties of these galaxies in comparison to other,
more powerful, radio galaxies at similar redshifts. We suggest a radio
power-ionization state relation.
