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.
This service represents the latest released version, and is updated when new versions are released. As of June, 2019 it
represents cnty19_1.