The FirePerimeter polygon layer represents daily and final mapped wildland fire perimeters. Incidents of 10 acres or greater in size are expected. Incidents smaller than 10 acres in size may also be included. Data are maintained at the Forest/District level, or their equivalent, to track the area affected by wildland fire.

Records in FirePerimeter include perimeters for wildland fires that have corresponding records in FIRESTAT, which is the authoritative data source for all wildland fire reports. FIRESTAT, the Fire Statistics System computer application, required by the USFS for all wildland fire occurrences on National Forest System Lands or National Forest-protected lands, is used to enter and maintain information from the Individual Fire Report (FS-5100-29). It is necessary to verify that attributes were correctly transferred from FIRESTAT, when the FirePerimeter data layer is finalized for the year. See FireStatQC attribute.

FirePerimeter polygons include all burned and unburned areas within wildland fire perimeters, unless otherwise directed. For example, include unburned islands, rocky outcrops, water bodies, and marshlands within a wildland fire perimeter, unless directed otherwise by USFS Line Officers. If not including all areas within a perimeter, make note in the metadata or comments field.

Use one feature for every wildland fire. This will result in a multi-part feature when the given fire perimeter, at a specific date and time, is non-contiguous (two or more spatially defined locations that are not adjacent). Multi-part polygons may result for some fires.

Prescribed fires are tracked in the Forest Service Activity Tracking System (FACTS) and are not to be included in the FirePerimeter layer. In the event that a prescribed fire escapes, then an Individual Wildland Fire Report is required, and the fire perimeter would be included in the FirePerimeter layer for only the area burned after escape.

For additional technical information, see: http://fsweb.datamgt.fs.fed.us/documents/current_data_dictionary/fire/FirePerimeterGISDD_TechnicalAddendum.doc