Abstract
The USDA Forest Service has conducted aerial surveys annually to produce a rich geospatial data set that includes damage severity, year and location of damage, damage agent, and tree species. We used the data from the western United States (1997-2023) and from Washington and Oregon (1947-2023) to produce Version 4.1 of a gridded mortality area data set. Mortality area is the canopy area of killed trees. We converted the polygons of damage into 1-km resolution annual rasters by damage agent-host tree species combinations. The methods are described in Andrus et al., Forest Ecology and Management, 2025.