Established in 1982, Government Code Section 65570 mandates FMMP to report biennially on even numbered years, the conversion of farmland and grazing land, and to provide maps and data to local government and the public. The Important Farmland survey area is based on Natural Resources Conservation Service (NRCS) modern soil surveys covering most non-governmental lands in California; 51 counties are fully or partially surveyed during the 2022 map update. Soil surveys specific to National Forests or other government land units are not surveyed. Beginning in 2000, SSURGO digital soil information was incorporated into the Fresno County Important Farmland data and the 2016 data began to incorporate the new NRCS Gridded Soil Survey (gSSURGO). Data subsequent to 2000 may have acreage and soil line differences due to incorporation of newer NRCS-SSURGO or gSSURGO editions.

Prior to the availability of SSURGO or gSSURGO, soil information was hand-transferred from the paper soil surveys. Older versions of the data have not been modified. The land use minimum mapping unit of ten acres has not changed, but digital soil units of less than one acre occur in the gSSURGO-enhanced Important Farmland data. The data between 2000 and 2014 incorporates SSURGO and the interaction of land use and soil components resulted in units of less than ten acres for categories such as Other Land. The 2016 data incorporates gSSURGO and will no longer merge resulting polygons less than one acre for any map category for that and future updates. For more information on gSSURGO, contact the USDA-Natural Resources Conservation Service: https://www.nrcs.usda.gov

The Other Land category was subdivided into Rural Residential (R), Vacant or Disturbed Land (V), Confined Animal Agriculture (Cl), and Nonagricultural and Natural Vegetation (nv) beginning with the 2004 data. Subsequently, Rural Residential (R) was subdivided into Semi-Agricultural and Rural Commercial Land (sAC) and Rural Residential (R) beginning with the 2006 data.

USDA NRCS soil surveys CA653 (Western Part of Fresno County); CA654 (Eastern Fresno Area).

Fresno County initial mapping year - 1984.

The central/eastern Fresno area has been mapped since 1984, and the western portion of the county was added in 2000 incorporating NRCS soil survey CA653.

Geodetic Model:

1984 to 2012 - North American Datum of 1927

2014 to 2022 - North American Datum of 1983

2022 county boundaries: California Department of Forestry and Fire Protection, Fire and Resource Assessment Program (FRAP) 2018 version (cnty 18_2) of California Counties GIS data. https://frap.fire.ca.gov

2022 Imagery source: USDA Farm Service Agency - National Agricultural Imagery Program (NAIP); Summer 2022; True color; 1 meter resolution. https://www.fsa.usda.gov

Google Incorporated; Various dates; True color; Google Maps and Streetview. https://www.google.com/maps