This data publication contains both vector and tabular digital data providing field plot measures and fuel treatment units used to assess the effectiveness of (WUI) fuel treatments burned through by the 2007 East Zone and Cascade megafires in central Idaho. Included are two ArcGIS shapefiles that contain the polygons representing units treated in 2006 for the Secesh Meadows area and the polygons representing the units treated between 1996 and 2006 for the Warm Lake area. The first tabular digital file contains specific fuel treatment and wildfire effects measured at paired treated and untreated field sites, both immediately post-fire and one year post-fire. Each site was composed of five field plots. Data collected at the five subplots per site were averaged to represent the site, which was the experimental unit. Data fields include site center locations, charred and uncharred ground cover fractions, litter and duff depths, overstory canopy closure, tree and sapling mortality, density, and basal area; tree, sapling and surface fuel biomass; and several other variables. The second set of data contains areal percentages of high, moderate, low, and unburned severity classes within wildland-urban interface (WUI) fuel treatment units extracted from immediate post-fire and one year post-fire Burned Area Reflectance Classification maps. The third file contains the amount of area burned daily for the Secesh Meadows area, Warm Lake area, and the total for the East Zone and Cascade megafires, as summarized from fire progression data.