Oak decline has been recorded on oak forests throughout the Ozark Plateau of Missouri since the 1970s, but severe drought in the late 1990s, combined with the advancing age of the Ozark forests, has intensified the levels of crown dieback and mortality beyond historical levels. The purpose of this project was to determine whether the Forest Vegetation Simulator (FVS) model could accurately predict the effect of oak decline on the Mark Twain National Forest (MTNF). Forest Inventory and Analysis (FIA) data were used to benchmark mortality magnitude and to adjust FVS growth projections. Data from inventory cycles 3 (1976-1977), 4 (1986-1987), and 5 (1999-2003) were available for approximately 150 oak stands on the MTNF. These data were translated into FVS-ready format and projected with and without the Oak Decline Event Monitor (ODEM) addfile. Actual growth and mortality versus projected values were compared. In the absence of harvesting or other major disturbance, baseline mortality per size class in a healthy forest is generally constant and departure from this constant may indicate unsustainable forest conditions. We compared current mortality rates to calculated mortality rates between inventory cycles 3 and 4 (i.e. prior to the latest decline events) to indicate whether mortality rates increased between inventory periods. This paper describes the FVS adjustments and methodology used; assesses the usefulness of FIA data and application of the ODEM addfile for this project; and discusses how FVS tools and comparison of baseline mortality rates could be used to predict future trends in Missouri oak forests.