We simulated long-term forest management activities on 16,000-ha wildland-urban interface in the Blue Mountains near La Grande, Oregon. The study area is targeted for thinning and fuels treatments on both private and Federally managed lands to address forest health and sustainability concerns and reduce the risk of severe wildfire. We modeled number of benchmark management scenarios through time, and examined potential wildfire behavior, stand structure, species composition, and other forest characteristics over the study area. The simulation models indicated that substantial area would require repeated thinning over time to meet desired forest density guidelines for the landscape as a whole. Fire models predicted significant reductions in crown fire activity for a specific weather scenario as a result of thinning and treatment of surface fuels. Substantial changes in stand structure and other characteristics were noted for the thinning versus no-treatment scenarios.