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City Boundaries and Annexations/Detachments


View City Annexations/Detachments Online

Desktop Viewer – Use this application to search, view, and download county/city/annexation/detachment boundaries as well as recorded annexation/detachment documents, maps, and legal descriptions.

Mobile Viewer – Using ArcGIS Online, this map is a little more smart phone friendly.

Open Data – City boundaries are also available on L.A. County’s Open Data Portal as a live stream.

Please remember, legal boundaries are only determined on the ground by surveyors licensed in the State of California.

The layers made available via these applications and for public downloading were derived from the Los Angeles County Cadastral Landbase. The offshore city boundaries were drawn per a decree of the United States Supreme Court. The coastline was digitized per LAR-IAC imagery.



Annexation No. 2018-04 to the City of Santa Clarita became effective November 15, 2018. The shapefile download includes terrorities annexed to City of Santa Clarita.

Reorganization No. 2016-08 to the City of Bradbury became effective January 11, 2018. This shapefile download includes territories detached from the City of Monrovia and annexed to City of Bradbury. Overlapping polygons indicate territories that transferred between cities.

Reorganization No. 2015-14 to City of Pomona ( Detachment from City of Diamond Bar) became effective April 13, 2017. This shapefile download includes territories detached from the City of Diamond Bar and annexed to City of Pomona. Overlapping polygons indicate territories that transferred between cities.

Annexation No. 2016-07 to the City of Santa Clarita became effective November 15, 2016. The shapefile download includes terrorities annexed to City of Santa Clarita.

Reorganization No. 2013-04 to the City of Rolling Hills became effective April 14, 2016. This shapefile download includes territories detached from the City of Rolling Hills and annexed to City of Rolling Hills Estates and City of Rancho Palos Verdes. Overlapping polygons indicate territories that transferred between cities.

Reorganization No. 2014 to the City of Los Angeles (Universal Studios area) became effective August 31, 2015. This shapefile download includes territories annexed to and detached from the City of Los Angeles and Unincorporated County areas.

Download Data

City Annexations This layer is used for locating past and present legal city boundaries and for retrieving annexation records. Overlapping polygons indicate territories that transferred between cities. This layer’s URL field can be used for retrieving recorded city annexation documents online.
City Boundaries Polygons This layer represents the most current incorporated city areas within Los Angeles County.
City Boundaries Lines This layer represents current linear city boundary locations.
County Boundary This shapefile includes only the land boundary outline of the County of Los Angeles


Other Useful Links

Official Areas Official, accumulated areas of incorporated cities per recorded legal descriptions as of December 31, 2014.
Land Records Thousands of scanned records are available here.
California Geoportal Plenty of GIS data is available here, including neighboring county boundaries.
Proposed City Changes For the purpose of planning, proposed annexations, detachments, and reorganizations to city boundaries are posted here.

Note that these proposed city boundary changes are subject to change before they become effective.

  LA County Cadastral Landbase Data : For the purpose of downloading DGN and GDB  file format.

State and County Boundaries Described

Los Angeles County is a subdivision of the State of California, legally described in California’s Government Code, Title 1. See State Boundaries, Sections 160-172. Los Angeles County’s boundary is legally described in the the California Government Code, Title 3, Article 2. See Boundaries of the Several Counties, Section 23119. For many years, the boundary between California’s and United States federal offshore territory was defined as three geographic miles from the line of mean lower low water per 382 U.S. 448, 1966. On December 15, 2014, a U.S. Supreme Court decree made this offshore boundary fixed (non-ambulatory) per a legal description in UTM coordinates.


Annexation Maps by City

Large format, high quality wall maps are available for each of the 88 cities in Los Angeles County in PDF format.

Agoura Hills Hermosa Beach Norwalk
Alhambra Hidden Hills Palmdale
Arcadia Huntington Park Palos Verdes Estates
Artesia Industry Paramount
Avalon Inglewood Pasadena
Azusa Irwindale Pico Rivera
Baldwin Park La Canada Flintridge Pomona
Bell La Habra Heights Rancho Palos Verdes
Bell Gardens La Mirada Redondo Beach
Bellflower La Puente Rolling Hills
Beverly Hills La Verne Rolling Hills Estates
Bradbury Lakewood Rosemead
Burbank Lancaster San Dimas
Calabasas Lawndale San Fernando
Carson Lomita San Gabriel
Cerritos Long Beach San Marino
Claremont Los Angeles Index Santa Clarita
Commerce Los Angeles Map 1 Santa Fe Springs
Compton Los Angeles Map 2 Santa Monica
Covina Los Angeles Map 3 Sierra Madre
Cudahy Los Angeles Map 4 Signal Hill
Culver City Los Angeles Map 5 South El Monte
Diamond Bar Los Angeles Map 6 South Gate
Downey Los Angeles Map 7 South Pasadena
Duarte Los Angeles Map 8 Temple City
El Monte Lynwood Torrance
El Segundo Malibu Vernon
Gardena Manhattan Beach Walnut
Glendale Maywood West Covina
Glendora Monrovia West Hollywood
Hawaiian Gardens Montebello Westlake Village
Hawthorne Monterey Park Whittier
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

CITY ANNEXATIONS - principal attributes include:

NO: corresponds with numbers on the tables displayed on City Annexation Maps.

ANNEX_No: is a text version of the "NO" field listed above. Because this field is only used for the Long Beach and Los Angeles Annexation Maps, this value is null for all other cities.

NAME: is the official name under which the annexation was filed.

TYPE: is used to indicate which legal action occurred.

  • A - represents an Annexation to that city.
  • D - represents a Detachment from that city.
  • V - is used to indicate the annexation was rendered Void or withdrawn before an effective date could be declared.
  • 33 - Some older city annexation maps indicate a city boundary declared 'as of February 8, 1933'.

ANNEX_AREA: is the land area annexed or detached, in square miles, per the recorded legal description.

TOTAL_AREA: is the cumulative total land area for each city, arranged chronologically.

SHADE: is used by some of our cartographers to store the color used on printed maps.

INDEXNO: is a matching field used for retriving documents from our department's document management system.

STATE (Secretary of State): Date filed with the Secretary of State.  These are not available for earlier annexations and are Null.

COUNTY (County Recorder): Date filed with the County Recorder.  These are not available for earlier annexations and are Null.

EFFECTIVE (Effective Date): The effective date of the annexation or detachment.

CITY: The city to which the annexation or detachment took place.

URL: This text field contains hyperlinks for viewing city annexation documents. See the ArcGIS Help for using the Hyperlink Tool.

FEAT_TYPE: contains the type of feature each polygon represents:

  • Land - Use this value for your definition query if you want to see only land features on your map.
  • Pier - This value is used for polygons representing piers along the coastline. One example is the Santa Monica Pier.
  • Breakwater - This value is used for polygons representing man-made barriers that protect the harbors.
  • Water - This value is used for polygons representing navigable waters inside the harbors and marinas.
  • 3NM Buffer - Per the Submerged Lands Act, the seaward boundaries of coastal cities and unincorporated county areas are three nautical miles from the coastline. (A nautical mile is 1,852 meters, or about 6,076 feet.)


CITY BOUNDARY POLYGONS - principal attributes include CITY_NAME and POPULATION, along with FEAT_TYPE as in the City Annexations feature class.

CITY BOUNDARY LINES - the principal attribute is BDRY_TYPE. Values include 'Coast', 'Land City', 'Land County', 'Pier', 'Breakwater', 'Water', and 'Ocean'.


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

Contact Information
Thierno Diallo
900 South Fremont Avenue

Alhambra, CA 91803

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