A large amplitude oscillation in the vertical column abundance of atmospheric OH has been observed in ground-based spectroscopic absorption measurements from Fritz Peak Observatory, Colorado (105 ¿W, 40 ¿N) during and after the partial solar eclipse of May 30, 1984. An initial OH reduction during the eclipse was followed by an underdamped oscillation having a period of about one hour; the OH abundances returned to normal values two hours after the eclipse termination. This is believed to be the first observation of a ''ringing'' response of any atmospheric constituent to a solar eclipse.