By all measures, wildfires in the western United States are becoming more extreme. Fires are growing larger and burning more intensely, and suppression costs are spiraling upward. Maximizing the effectiveness of fuel treatments at the landscape scale is key given limited resources and the inability to treat all areas likely to burn in a wildfire. Research forester Theresa Jain with the Rocky Mountain Research Station collaborated with fellow Station scientists along with colleagues from research institutions across the country to synthesize existing scientific literature on landscape-scale fuel treatment effectiveness in North American ecosystems through a systematic literature review. The team identified 127 studies that addressed the fuels treatment effectiveness using simulation modeling, empirical analysis, and case studies. The studies show that fuel treatments reduced negative outcomes of wildfire and often promoted beneficial wildfire outcomes. Weather conditions influenced the effectiveness of treatments, and effectiveness lessened over time following treatment, pointing to the need for maintenance treatments. The studies also emphasized the importance of treating multiple fuel layers (canopy, ladder, and surface) to reduce fire spread and severity. Fuel treatments also contributed to fire suppression efforts by reducing costs and facilitating suppression activities, such as fireline construction. The science team has developed a fuel treatment effectiveness framework with measurable criteria to better understand how stand-level fuel treatments collectively contribute to broader landscape-level fuels management goals.