Spectroscopic observations have been made of the resonance absorption of sunlight by terrestrial OH. Changes in the daytime OH slant column absorption were observed, from which lower limits on the vertical abundances were calculated. These atmospheric vertical abundances were on the order of 1014/cm2 with apparent large daytime variations. The tropospheric contribution is expected to be not more than 1013/cm2. The abundances reported here are thus predominately due to stratospheric OH.