Estimating air emissions from wildfires and prescribed burns has always been difficult because the information needed to make the estimates was so decentralized. Using newly developed techniques that combine satellite data with fire information reported from the ground, STI has developed a series of national wildland fire emissions inventories and agricultural fire activity databases for 2003-2011 and 2014 on behalf of the U.S. Environmental Protection Agency (EPA). These inventories and databases served as the basis for fire sector emissions in the 2005, 2008, 2011, and 2014 versions of the EPA's National Emissions Inventory of air pollutants and were used to develop average-year fire inventories for EPA's regulatory modeling.