The fire perimeter and prescribed fire feature services provide a reasonable view of the spatial distribution of past large fires but is in no way complete. Some fires are missing because historical records were lost or damaged, were too small for the minimum cutoffs, had inadequate documentation or have not yet been incorporated into the database. Due to missing perimeters this data should be used carefully for statistical analysis and reporting (see Use Limitation in metadata). Other errors with the fire perimeter database include duplicate fires and over-generalization. Additionally, over-generalization, particularly with large old fires, may show unburned "islands" within the final perimeter as burned. Users of the fire perimeter database must exercise caution in application of the data. Careful use of the fire perimeter database will prevent users from drawing inaccurate or erroneous conclusions from the data. Please contact the California Department of Forestry and Fire Protection’s Fire and Resource Assessment Program for a detailed explanation of the limitations of the data. This data is updated annually in the spring with fire perimeters from the previous fire season. As of April 2023, it represents fire22_1.  CAL FIRE (including contract counties), USDA Forest Service Region 5, USDI Bureau of Land Management & National Park Service, and other agencies jointly maintain a comprehensive fire perimeter GIS layer for public and private lands throughout the state. The data covers fires back to 1878. Current criteria for data collection are as follows: CAL FIRE (including contract counties) submit perimeters ≥10 acres in timber, ≥50 acres in brush, or ≥300 acres in grass, and/or ≥3 damaged/ destroyed residential or commercial structures, and/or caused ≥1 fatality. All cooperating agencies submit perimeters ≥10 acres. Firep22_1 was released in April 2023. Three hundred five fires from the 2022 fire season were added to the database. The 2021 Dotta (part of Beckwourth Complex), Greenhorn, and Hartman fire perimeters were added. Another 45 fires were added by USFW from 2015-2021. The 1988 Hessel fire was added in LNU. The 2019 Cave fire was replaced with a more detailed perimeter submitted by Santa Barbara County. The 2017 Hudson, 2017 Lake, 2017 Jones, 2017 "37", 2019 Tucker, and 2019 Refuge perimeters were replaced with imagery digitized perimeters from USFW. Attributes were updated for 32 records. One hundred ten perimeters were removed due to duplication or being completely contained outside of California state borders. The field IRWINID was added to provide a unique ID; fires before 2022 are lacking this attribution (with the exception of those added in this publication where possible). The following fires were identified as meeting our collection criteria, but are not included in this version and will hopefully be added in the next update: 2022 Cable (CAL FIRE, AEU), 2022 All American (BIA, CRA). Includes separate layers filtered by criteria as follows: California Fire Perimeters (all): Unfiltered. The entire collection of wildfire perimeters in the database.  It is scale dependent and starts displaying at the country level scale.  Recent Large Fire Perimeters (>=5000 acres): Filtered for wildfires greater or equal to 5,000 acres for the last 5 years of fires (2018-2022), symbolized with color by year and is scale dependent and starts displaying at the country level scale. Year-only labels for recent large fires. California Fire Perimeters (1950+):  Filtered for wildfires that started in 1950-present.  Symbolized by decade, and display starting at country level scale. Prescribed Burns:  Unfiltered.  The entire collection of prescribed burn perimeters in the database.  Begin displaying at county level scale.  Detailed metadata is included in the following documents:"fire22_1" Metadata: Metadata for Firep22_1"rxburn22_1" Metadata: Metadata for Prescribed Fires Rxburn22_1For any questions, please contact the data steward:Kim Wallin, GIS SpecialistCAL FIRE, Fire Resource and Assessment Program (FRAP)

kimberly.wallin@fire.ca.gov