Observations of the fluxes and deposition velocities of SO2 and O3 to a Black Cherry/Red Maple forest were made from before leafout (April) to leaf senescence and fall (October) 15 m above the Kane Experimental Forest,located adjacent to the Allegheny National Forest, in Northwestern Pennsylvania. Additional observations included fluxes of CO2, water vapor, heat, and momentum, normal meteorological variables, including profiles of temperature and wind speed above the canopy, and observations of leaf growth and respiration. Changes in trace gas fluxes over both seasonal and diurnal cycles are noted. The impact of surface wetness, leaf area, soil temperature, and other environmental variables on the fluxes are discussed. Observations are compared to model results from the latest version of the NOAA Multi-Layer Model for deposition velocity. The model had very small bias over all observations. Strengths and weaknesses of the model under specific conditions are discussed.