Modeling capabilities of the FARSITE fire area simulator have been expanded to include post-frontal combustion and smoke production. FARSITE previously simulated only fire growth, with fire behavior calculations applicable only to the edge of a fire (Finney 1998). FARSITE can now simulate the burnout of duff and woody fuels behind the flaming front. A time dependent combustion history for both flaming and smoldering burning allows the smoke and heat production to be displayed for all or part of the fire simulation area. FARSITE accounts for both temporal and spatial variation in conditions. FARSITE software and information can be found at www.fire.org. Post-frontal combustion is defined as fire activity occurring after the passage of the advancing edge of the fire. Post-frontal combustion is essential to the production of smoke and to understanding patterns of heat-evolution from large fires that are believed critical to lofting of the smoke and interactions with the atmosphere (Rothermel 1991, 1994, Linn and Harlow 1998). FARSITE does not include modeling of smoke dispersion, but the output from FARSITE could be used for such a model.