Post-fire assessments are generally conducted by U S Department of Agriculture (USDA) Forest Service or U S Department of the Interior (DOI) Burned Area Emergency Response (BAER) teams after large wildfires. A BAER team's primary objective is to rapidly identify post-fire effects and determine whether the wildfire has created unacceptable risk to human life and safety, property, and critical natural or cultural resources. The BAER team may manage risk by recommending treatments for land, channel, road, and trail stabilization and for public safety (Calkin and others 2007; USDOI BLM 2007; Napper2006;USDAForestService2004). A map that reflects the fire's effects on the ground surface and soil condition is needed in order to rapidly assess fire effects, identify potential areas of concern, and prioritize initial field reconnaissance. Thus, it is important to develop a soil burn severity map as quickly as possible during the initial post-fire assessment phase. This map identifies the fire-induced changes in soil and ground surface properties that may affect infiltration, runoff, and erosion potential (Parsons 2002). It also enables BAER teams to achieve their primary objective of identifying areas of unacceptable risk to a critical value and where rehabilitation treatments may be most effective (Robichaud and others 2008b; Calkin and others 2007; Robichaud and others 2000) BAER teams have often struggled with accurately mapping post-fire soil burn severity. This challenge has grown in recent years as larger fires affect multiple jurisdictions, agencies, and landowners. There is a need for consistent methodologies, assessment tools, and terminology that quickly and accurately identify the post-fire conditions In response, BAER teams are using many geospatial assessment tools to expedite post-fire soil burn severity assessment. However, little standardization of methodology or terminology has occurred in soil burn severity mapping and field verification. This guide provides direction to BAER teams to promote consistency in post-fire soil burn severity mapping. With a field-validated soil burn severity map, BAER teams can more readily evaluate secondary wildfire effects, including increased runoff, erosion, flooding, sedimentation, and vulnerability to invasive weeds, and can predict natural revegetation (Calkin and others 2007). This field guide clarifies concepts, terminology, context, and use of the soil burn severity map. Field indicators and classification guidelines are also provided for use in mapping. Using this field guide will ensure consistency in map products across ecoregions around the United States. Components of this guide include: terminology and definitions, the role of remote sensing and geographic information systems (GIS) in BAER assessments, guidelines for identifying soil burn severity classes in the field, discussion on soil burn severity within general vegetation density models, photo series showing representative postfire soil and ground conditions, and field data sheets to assist in data collection for mapping soil burn severity. This guide provides a reference for ground conditions, soil characteristics, and vegetation density models that most closely match the field setting. Observations can be compared with those in the tables and photos to make a determination of the soil burn severity classification at a field location. This guide presents representative conditions only. Actual ground conditions will vary within the categories.