Do Hazardous Fuel Reduction Treatments Prevent Wildfire Disasters? Evidence from 25 Years of Interventions in US National Forests

We estimate whether federal hazardous-fuel treatments prevent wildfire disasters at the wildland-urban interface (WUI). We combine U.S. Forest Service fuel-treatment polygons with fire perimeters, ignition points, WUI polygons, and LANDFIRE topography. A nearest-point difference-in-differences imputation design compares WUI polygons threatened by the same fire and lying in the same ignition direction, using distance from ignition to order treated and untreated observations. In 92,720 fire-WUI observations from 601 fires, polygons whose nearest path to ignition intersects a completed prior-five-year treatment are 11.61 percentage points less likely to burn. Adding wind, elevation, PRISM climate, road, fuel, slope, and aspect controls gives an estimate of 9.56 percentage points. Secondary outcomes show lower WUI burn share, fewer burned acres, and fewer housing units in burned polygons. Effects are largest in intermix WUI, while interface effects are weaker and the burned-acres interface effect is less stable. The treatment-type split shows stronger protection from prescribed-fire-based treatment paths than mechanical treatment paths across outcomes, with both directions negative. All evidence indicates that federal hazardous-fuel treatments alter fire behavior and reduce realized wildfire disasters in the WUI when a wildfire threat is realized.