California County Boundaries

This dataset provides an initial offering as "best available" at 1:24,000 scale. Hosted on CAL FIRE AGOL.

In late 1996, the Dept of Conservation (DOC) surveyed state and federal agencies about the county boundary coverage they used. As a result, DOC adopted the 1:24,000 (24K) scale U.S. Bureau of Reclamation (USBR) dataset (USGS source) for their Farmland Mapping and Monitoring Program (FMMP) but with several modifications. Detailed documentation of these changes is provided by FMMP and included in the lineage section of the metadata.

A dataset was made available (approximately 2004) through CALFIRE - FRAP and the California Spatial Information Library (CaSIL), with additional updates throughout subsequent years. More recently, an effort was made to improve the coastal linework by using the previous interior linework from the 24k data, but replacing the coastal linework based on NOAA's ERMA coastal dataset (which used NAIP 2010).

In this dataset, all bays (plus bay islands and constructed features) are merged into the mainland, and coastal features (such as islands and constructed features) are not included, with the exception of the Channel Islands which ARE included.

Data and Resources

Field Value
EPSG 4269
collection_name Boundary Datasets
spatial {"type": "Polygon", "coordinates": [[[-124.48200988769531, 32.528831481933594], [-114.13121032714844, 32.528831481933594], [-114.13121032714844, 42.00950622558594], [-124.48200988769531, 42.00950622558594], [-124.48200988769531, 32.528831481933594]]]}
Groups
  • NSF
  • United States
Tags
  • California
  • NSF
  • United States
  • boundary
  • county
isopen False
metadata_created 2026-10-30T17:08:05.464294
metadata_modified 2026-10-30T17:08:05.464299
notes This dataset provides an initial offering as "best available" at 1:24,000 scale. Hosted on CAL FIRE AGOL. In late 1996, the Dept of Conservation (DOC) surveyed state and federal agencies about the county boundary coverage they used. As a result, DOC adopted the 1:24,000 (24K) scale U.S. Bureau of Reclamation (USBR) dataset (USGS source) for their Farmland Mapping and Monitoring Program (FMMP) but with several modifications. Detailed documentation of these changes is provided by FMMP and included in the lineage section of the metadata. A dataset was made available (approximately 2004) through CALFIRE - FRAP and the California Spatial Information Library (CaSIL), with additional updates throughout subsequent years. More recently, an effort was made to improve the coastal linework by using the previous interior linework from the 24k data, but replacing the coastal linework based on NOAA's ERMA coastal dataset (which used NAIP 2010). In this dataset, all bays (plus bay islands and constructed features) are merged into the mainland, and coastal features (such as islands and constructed features) are not included, with the exception of the Channel Islands which ARE included.
num_resources 2
num_tags 5
title California County Boundaries