This report contains emission factors (weight of pollutant per acre burned) for estimating atmospheric emissions from forest fires (especially wildfires) for each of the ten U.S. Forest Service regions in the U.S. The pollutants considered are: total particulates, hydrocarbons, carbon monoxide, nitrogen oxides, and sulfur oxides. Data on acreage consumed by wildfires are used with the factors to estimate mass emissions for each region. The effects of such variables as terrain, density of vegetation coverage, type of vegetation, wind speed, and humidity are also discussed. Finally, proposed approaches to mathematically correlate these variables (via empirical and theoretical models) with both emission factors and mass emissions are presented.