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Early Historic Surveys

Sample of an early plat

This layer was created for retrieving the earliest recorded surveys of original Spanish and Mexican land grants (Ranchos), along with original plats of the United States Public Lands Survey System (PLSS). The URL field points to documents (PDF) on the Land Records Information website, hosted by the Los Angeles County Department of Public Works (DPW).

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Ranchos and Townships

The source data (plsa-1997) was obtained from Cal-Atlas in 2006.

If you download this source data, please note the included README file explaining the original source shapefile’s history and accuracy. Portions of this state wide shapefile pertaining to Los Angeles County were extracted, clipped, and projected to the California State Plane, NAD83, Zone 5 Coordinate System. Polygons representing Sections were dissolved into their parent Townships and attribute schema was simplified. The last step was to add a URL field for hyperlinking to scanned original plats on the County DPW file server.

Users of the original source shapefile, as well as this derived shapefile, need to understand they were not drawn per surveys; They are a means to retrieve recorded scans of recorded survey documents.

Other Resources

Official BLM Federal Land Records – This site is a valuable resource for original land patents and plats. If anyone finds a document here, or feels that a document is missing from the DPW Land Records site, please contact John Guild by email at jguild@dpw.lacounty.gov.

The BLM maintains branch offices for each state, and the Cadastral Survey Records Office in Sacramento is also worth visiting.

Grants of Land in California made by Spanish or Mexican Authorities provides a valuable historical background.

The BLM provides information on the 2009 Manual of Surveying Instructions, available for purchase.

Using GIS Data on this site

GIS Data downloaded from this site generally requires GIS software to view. Click here for a list of GIS Data Viewers

GIS data available on this website is provided AS IS - please read the GIS Data Portal Terms of Use

Data Field Descriptions

SURVEY - Name of the original Land Grant or Township.
REF - The land patent book and page that documented the land grant.
URL - Links to a pdf copy on the Los Angeles County DPW server.

GIS Source Information
Database Name: n/a
Feature Class Name:
Feature Dataset Name (if applicable):
Reference Date: 2013
Accuracy: Thomas Brothers
Update Frequency: As Needed
Access Constraints:None

Contact Information
Marianne Jeffers
Cadastral Engineer III
Los Angeles County
Public Works


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