An interactive microcomputer environment, the Forester's Workspace, is introduced and used to illustrate the estimation of residual fuel biomass for lodgepole pine and white spruce trees and stands in Alberta. Estimates are made for individual trees using the prediction relationships developed by Johnson et al. (1990) and tree estimates are integrated with typical variable radius plot sampling data. Estimates are made for total crown, live crown and foliage as well as for roundwood diameter classes (0-.5, .5-1, 1-3, 3-5, 5-7, and 7-10 cm). This interactive analysis environment allows for easy modification of the basic predictive relationships. The format of resulting estimates can be tailored to meet the needs of the analyst. © by the Society of American Foresters. Abstract reproduced by permission.