Monitoring Trends in Burn Severity (MTBS) is a multi-year, interagency project designed to consistently map the location, extent and associated burn severity of large fires occurring on all lands of the United States from 1984 to present. The suite of mapping, data and analysis products facilitated by the project are derived from satellite data using image processing and analysis techniques established by the USGS and USFS. These products provide a continuous record of burn severity trends to assess the effectiveness of national fire management policies, and also offer essential and consistently derived geospatial data that meet several agency and interagency resource management application needs. Ground-based assessments of burn severity, such as the Composite Burn Index (CBI), can be used to both establish severity class thresholds and validate burn severity information mapped using satellite data. Due to the lack of temporally and spatially consistent field data throughout the data record, MTBS burn severity products are not currently validated. However, available CBI data can be used to validate and/or calibrate burn severity thresholds for recent and future fire events occurring in similar biophysical settings. The objective of this presentation is to provide users with an overview of the MTBS project, and how to access and appropriately use MTBS data and products. The presentation will also include a general discussion on how CBI field data are acquired and may be contributed to a national CBI database using FFI. An additional brief discussion will summarize the procedure of using CBI data to validate MTBS thematic burn severity data products and establish thresholds to classify continuous burn severity index data into categorical burn severity classes. This webinar was hosted by the Lake States Fire Science Consortium.