The OH vertical column abundances measured with the Pepsios spectrometer from the National Oceanic and Atmospheric Administration Aeronomy Laboratory's Fritz Peak Observatory (40¿N,105¿W) for the 1977-1982 period are presented. Analysis of the ground state absorption shows a general seasonal variation of 28% with maximum in January and minimum in July. An A.M.-P.M. asymmetry in the observations is found which has a 27% seasonal reversal, which is in phase with total ozone. A unique perturbation of +30% is found for summer 1982 OH abundances, which is attributed to the El Chichon eruption in April 1982.