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HomeGovernment CodeDiv. 1Ch. 2Art. 2§ 23138 San Francisco County Boundaries

§ 23138 San Francisco County Boundaries

Government Code·California
AI Summary·Official Text·Key Terms·Related Statutes·References
AI SummaryVerified

§ 23138 San Francisco County Boundaries

Key Takeaways

  • •San Francisco's borders start at the Pacific Ocean and go up the coast to the entrance of San Francisco Bay.
  • •The border then goes through Point Bonita and Point Cavallo to the southeast point of Angel Island.
  • •From there, it goes north to Golden Rock, then southeast for 4.5 miles to a point where Contra Costa, Alameda, and San Francisco meet.
  • •The Farallon Islands are part of San Francisco.

Example

If you are on Angel Island, you are within San Francisco's borders.

The law says the border goes through Angel Island, so the island is part of San Francisco.

AI-generated — May contain errors. Not legal advice. Always verify source.

Official Source
View on CA.gov

§ 23138 San Francisco County Boundaries

The boundaries of San Francisco city and county are as follows: Beginning at the southwest corner, being the northwest corner of San Mateo, in the Pacific Ocean, on the extension of northern line of T. 3 S., of Mount Diablo base; thence northerly along the Pacific Coast, to its point of intersection with the westerly extension of the low-water line on the northern side of the entrance to San Francisco Bay, being the southwest corner of Marin and northwest corner of San Francisco; thence easterly, through Point Bonita and Point Cavallo, to the most southeastern point of Angel Island, all on the line of Marin; thence northerly, along the easterly line of Marin, to the northwest point of Golden Rock (also known as Red Rock), being a common corner of Marin, Contra Costa, and San Francisco; thence due southeast four and one-half statute miles to a point established as the corner common to Contra Costa, Alameda, and San Francisco; thence southeasterly, on the western line of Alameda County to a point on the north line of T. 3 S., R. 4 W., M D. B. & M.; thence westerly on the township lines and an extension thereof to the place of beginning. The islands known as the Farralones (Farallons) are a part of said city and county. (Added by Stats. 1947, Ch. 424.)

Last verified: January 22, 2026

Key Terms

san franciscocontra costapacific oceanpoint bonitapoint cavalloangel islandgolden rockthe farallon islands

Related Statutes

  • § 23121 Marin County Boundaries
  • § 23107 Contra Costa County Boundaries
  • § 23101 Alameda County Boundaries
  • § 23108 Del Norte County Boundaries
  • § 23112 Humboldt County Boundaries

References

  • Official text at leginfo.legislature.ca.gov
  • California Legislature. Government Code. Section 23138.
View Official Source