Beginning in 2006, the Monitoring Trends in Burn Severity (MTBS) project has been mapping and assessing the burn severity of all large fires that have occurred in the United States. The primary objective of MTBS is to provide consistent summary information on the location, extent and magnitude of burn severity of fires on all lands in the United States including Alaska and Hawaii for 1984-2010. All known large historical fires have been mapped by the USGS and the USFS Remote Sensing Applications Center (RSAC). The burn severity assessments are used to plan mitigation, recovery, and other land management activities; and to assess short- and long-term impacts and trends of fire at local, regional, and national scales. Over 15,000 fires from 1984 to 2010 from all 50 States have been mapped. For each fire, pre- and post-fire Landsat imagery is selected and processed to delineate a perimeter and assess the magnitude of change in vegetation that occurred due to fire. All processed fires are available for download at http://mtbs.gov. As of August 2013, over 1,500 fires from 2011 have been completed and mapping the 2012 fires has commenced. Additional efforts are underway to utilize satellite fire detections to discover and map historical and current undocumented fires.