Sufficient data exist within the literature to allow the woody biomass of two subspecies of Artemisia tridentata, basin big sagebrush (Artemesia tridentata ssp. tridentata), and Wyoming big sagebrush (Artemesia tridentata ssp. wyomingensis), to be classified into 3 standard fuel size classes: 0 to 1/4 inch (0 to 0.63 cm), 1/4 to 1 inch (0.64 to 2.54 cm), and 1 to 3 inches (2.55 to 7.62 cm). Of primary significance to fire behavior is a technique wherein the biomass is modified and expressed as a fuel load referenced to the canopy area. A table relates the fuel load by size class to the height and canopy area of the shrub. Estimates of the average load by size class - necessary for predicting fire behavior - can be made for areas where the shrub dimensions and number densities are known. Those less interested in fire will find this table an easy-to-use reference to the physical description of these shrubs. Although classsification of the woody biomass by size class was a major result, regressions of the leaf and woody biomass on canopy area and height and regressions of canopy area on height are presented on a comparable basis for both subspecies. Regressions of biomass on height and canopy area suggest that wyomingensis is similar to tridentata up to a shrub height of 0.8 m where the biomass for similar crown dimensions increases 1.5 and 1.8 fold at greater heights. © Society for Range Management. Abstract reproduced by permission.