This paper examines extraboard operations and management at TriMet, the transit provider for the Portland Oregon metropolitan area. The extraboard consists of a pool of operators who fill open work resulting from absences and other causes. The paper first examines the general performance of the extraboard in filling open work, drawing on seven years of daily operations data from three bus garages. It then presents statistical analyses focusing on open work patterns and the effects of selected work rules on operator utilization and service delivery. Lastly, suggestions are made for improving the efficiency of extraboard operations.