  We report simultaneous conjugate Ramsey-Bord\'e interferometers with a sample
of low-mass (lithium-7) atoms at 50 times the recoil temperature. We optically
pump the atoms to a magnetically insensitive state using the $2S_{1/2} -
2P_{1/2}$ line. Fast stimulated Raman beam splitters address a broad velocity
class and unavoidably drive two conjugate interferometers that overlap
spatially. We show that detecting the summed interference signals of both
interferometers, using state labeling, allows recoil measurements and
suppression of phase noise from vibrations. The use of "warm" atoms allows for
simple, efficient, and high-flux atom sources and broadens the applicability of
recoil-sensitive interferometry to particles that remain difficult to trap and
cool.
