  This is an account of the Millimeter Wave Observatory, a 4.9 meter diameter
antenna facility that pioneered continuum observations of planets and
interstellar molecular spectroscopy from 1971 to 1988. The circumstances of its
founding, development of its instrumentation, and major research contributions
are discussed. The MWO role in training of personnel in this new field is
illustrated by a listing of student and postdoctoral observers, with titles of
PhD theses that included MWO data.
