Authors: Karin L. Riley; Matthew P. Thompson; Jessica R. Haas; Dan R. LoefflerWhile fuel treatment effects are relatively well-studied at the site level, their effects at the landscape level are more challenging to ascertain and are more rarely studied. Here, we explore how fuel treatments changed the modeled burn probabilities and flame lengths in the neighborhood of fuel treatments, and summarize these changes the landscape level. We used spatial optimization to schedule fuel treatments across the landscape under different budget levels, selecting fuel treatment sites based on their potential to prevent damage to highly valued resources sensitive to fire. Because fuel treatments slow fire rate of spread and increase opportunities for containment, producing smaller fires, we estimated reductions in fire suppression costs resulting from fuel treatments. We illustrate variation in the magnitude of changes in burn probability, flame length, and fire suppression costs across the different budget levels and fuel treatment sites. We present results from a case study landscape encompassing the Sierra National Forest in California, USA, building from recent geographically-relevant research on fuel treatment opportunities, fire simulation, risk assessment, and incident response planning.