Over the past four years scientists have cooperatively monitored fire behavior and smoke chemistry, on a number of large prescribed fires in the Province of Ontario. Primary cooperating agencies include Forestry Canada, the United States Forest Service, the National Aeronautics and Space Administration, the United States Defense Nuclear Agency, and the Ontario Ministry of Natural Resources. Detailed investigations of fire dynamics, convection column dynamics, and smoke chemistry have taken place on seven fires to date. The general goal of this research activity is to model the complete mass fire process, from energy release rates on the ground, through convection column establishment and downwind smoke dispersal. This information is being presented to fire management agencies to assist in the conducting of safe and effective prescribed fire programs. © by the Society of American Foresters. Abstract reproduced by permission.