Results/Conclusions Spatial extent of crown fire occurrence and active crown fire occurrence was significantly higher (p=.008 and p<.001, respectively) for simulations that used average CBD inputs in summer fire scenarios, while only active crown fire occurrence was significantly higher (p<.001) in winter fire scenarios. In both control and treatment simulations, mean fire areas were significantly larger in summer burns (p=.001). In crown fire area, summer burns showed significantly greater crown fire extent with heterogeneous (p<.001) and homogeneous (p=.002) canopy layer treatments than did winter burns. Reaction intensities with heterogeneous canopy mapping were significantly higher (p<.001) in summer burns than winter burns. Summer burns also showed significantly higher (p<.001) heat per unit area compared to winter burns when both landscape sets were modeled with heterogeneous and homogeneous canopies. Spatially heterogeneous canopy fuels provide natural crown fire “braking” that can lead to landscape-level diversity enhancement. Heterogeneity of crown fuels is important to capture in models for prescribed crown fire scenarios. Winter burns are shown to produce less crown fire occurrence and lower probability of active crown fire spread than summer burns.