Log In

Township Range Section, Rancho Boundaries

trsrThis dataset contains the boundaries of the Public Land Survey System (PLSS) – Township Range Section boundaries, as well as the boundaries of the Ranchos  and Landgrants that pre-dated the PLSS.  In general these match the USGS topographic Quad Sheets from the US Geological Survey.

Note – some boundaries may not match parcel boundaries where that is logical – we haven’t had the time to complete that movement.

These are historic boundaries that still have impacts upon the names and geography of Los Angeles county today.  For example, where does the name “Verdugo Mountains” come from – it comes from the Rancho established there.


PLSS (from wikipedia)

The Public Land Survey System (PLSS) is the surveying method used historically over the largest fraction of the United States to survey and spatially identify land parcels before designation of eventual ownership, particularly for rural, wild or undeveloped land. It is sometimes referred to as the rectangular survey system (although non rectangular methods such as meandering can also be used)


The Spanish and, later, Mexican governments encouraged settlement of territory now known as California by the establishment of large land grants called ranchos, from which the English word ranch is derived. Land-grant titles (concessions) were government-issued, permanent, unencumbered property-ownership rights to land called ranchos.

tsrs_quadWhy this dataset?

This dataset was created in order to integrate the boundaries from two different datasets – a Rancho Boundary file created by Mike McDaniel of El Segundo, and a parcel-accurate Township Range Section file created by the LA County Department of Public Works.  Thanks to both of those entities for creating those valuable source files.  There are many sources of this data out there, but the rancho are holes in the PLSS datasets and the TRS is a hole in the rancho files.  This combines both of those.

Method of conflation

To merge these two datasets together, they were combined, and then any holes and overlaps were conflated to match the Rancho boundaries that were created by Mike McDaniel.  When there were questions I used the USGS topographic quad sheets to verify numbering and naming.  We have not (yet) attempted to snap the boundaires to parcels where they most likely should be.


Download the data



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

These fields contains information about ranchos/landgrants

  • LANDGRANT - name of the land grant
  • NAME_2 - secondary name of the land grant
  • GRANTEE__P - the Grantee Name
  • PATENTEE__ - Secondary Grantee Name
  • GRANT_NO - Grant Number
  • GRANTED - Date granted
  • PATENT_DAT - Date patented
  • SURVEYOR - Survery Name
  • SURVEY_DAT - Survey Month and Date
  • CO - County
  • TYPE - Rancho (Ro) or Pueblo
  • ACRES_1 - Number of acres of the grant

The fields contain information about the PLSS

  • SECTION - Section Number
  • MERIDIAN - The meridian
  • TOWNSHIP - Township Number
  • RANGE - Range Number
  • NOTES - Notes that show changes in information
  • FeatType - IF this is a TRS or a Rancho

GIS Source Information
Database Name: eGIS_Basemaps_Grids
Feature Dataset Name (if applicable):
Reference Date: 2013
Accuracy: Other
Update Frequency: As Needed
Access Constraints:None

Contact Information
Steve Steinberg
Geographic Information Officer
Los Angeles County
Internal Services Department
9150 E. Imperial Hwy, MS#3
33.916650, -118.132255
Downey, CA 90242
(562) 392-7126

3 comments to Township Range Section, Rancho Boundaries

Leave a Reply