Pure rotation line emissions from highly rotationally excited OH have been observed between 80 and 110 km tangent height under both nighttime and daytime quiescent conditions. Data were obtained using the cryogenic CIRRIS 1A interferometer, operated on the Space Shuttle. Transitions from OH (v=0--2, N'≤33) were identified between 400 and 1000 cm-1, corresponding to states with energies as high as 23000 cm-1. These are the first definitive observations of OH pure rotation transitions in the airglow, and by far the highest N levels observed in any type of OH airglow emission spectrum. The present observations of highly excited rotational states of OH parallel those made during recent field studies of NO and laboratory studies of OH, NO, and CO. ¿ American Geophysical Union 1992