Most of Black Point-Green Point was built recently: 7% of its homes predate 1940 and the median home dates from 1975. Below: maps from 1914 on and the census since 2000.
What drives Black Point-Green Point’s History grade
On its age, its old homes and the National Register, Black Point-Green Point is more historic than 24% of U.S. towns. Its share of homes from before 1940 holds the grade up; its National Register listings pull it down.
C−
HistoryA character grade: shown, never part of Black Point-Green Point’s overall grade.
Few California towns list much on the Register (a typical California town has 0.0 per 10,000 residents, the U.S. 2.4), so Black Point-Green Point’s 0.0 sits below most of its state (31% of California towns have fewer) while its 0 listings outnumber those of 23% of U.S. towns.
How sure. Graded on two of the three inputs, so a change in either one moves the letter more than it would with three. The pre-1940 share is a Census survey estimate (±4.9 points).
Founding year: our sources. Homes: Census ACS 2020–24. National Register: National Park Service, May 2026 list; each listing counted once (boundary changes and added documentation belong to their listing), and a historic district counts its contributing buildings. How TownRatings grades history →
What stands out about Black Point-Green Point’s past
Read from the archive, the National Register and the record. The page puts what stands out first.
Lost post offices, old corners and places now gone
Two other post offices opened and closed inside today’s town.
Black Point
1865–1952
Grandview
1905–1944
18601940today
Hamlets and corners on the map
Black Point
Gone or out of use
Black Point Schoolschool
US Post Offices dataset (Blevins & Helbock, CC0). Places and cemeteries from the USGS Geographic Names Information System (2021).
On the map
Black Point-Green Point on the map, 1914 to 1980
Every edition of the U.S. Geological Survey’s map of Black Point-Green Point. Tap a year, or press play to watch the town change.
1914Petaluma sheet · 1:62,500
U.S. Geological Survey historical topographic maps (public domain), via Esri’s collection of the scans. The red ring marks the center of Black Point-Green Point.
The story
How Black Point-Green Point came to be
From Wikipedia’s history of Black Point-Green Point.
Black Point was part of the Rancho de Novato land grant. The 1880 History of Marin County by Alley, Bowen and Co. mentions "a man by name of Day" who "settled on an island in Novato township which has since borne his name" in 1851. This island is still known as Day Island. According to the book, several more settlers moved into the area in 1853. Some of them owned land there, while others were squatters, a problem common across the county. Lumber that came from Black Point was used to build part of the USS Saginaw, a steamer built at the Mare Island Naval Shipyard. It served in the navy until 1870, when it ran aground on a reef not far from Ocean island. Deer Island, a former island east of Olive Avenue, actually was an island in the early 1900s. The house on the island, owned by Antonio DeBorba, whose shop on Grant Avenue is still intact, was completely encompassed by water, and his ho…
How does Black Point-Green Point rank for history?
Black Point-Green Point is more historic than 24% of U.S. towns. The History grade combines the town’s founding era, the share of homes built before 1940 and its National Register listings. It’s a character grade, so it isn’t part of the overall grade. How it works.
How old are the homes in Black Point-Green Point?
7% of Black Point-Green Point’s homes were built before 1940 (Census estimate, ±4.9 points), against a typical 3.4% for a California town; the median home was built in 1975.
Founding dates: Wikidata, Wikipedia, the U.S. post office records of Blevins & Helbock (CC0) and the Census. Homes by year built: Census ACS 2020–24. National Register of Historic Places: National Park Service (list of May 22, 2026). Old photos, postcards and papers: Wikimedia Commons, the Library of Congress and other public archives, credited on each item’s page. Maps: U.S. Geological Survey historical topographic maps (via Esri) and Sanborn fire-insurance maps (Library of Congress). History text and census tables: Wikipedia (CC BY-SA 4.0). Places that used to be: USGS Geographic Names Information System (2021).
From Wikipedia, U.S. Geological Survey historical maps, U.S. Census counts (via Wikipedia), the US Post Offices dataset (Blevins & Helbock) and the USGS Geographic Names Information System. Archive images are copied here with their credits and licenses, shown on each photo’s page. Refreshed monthly.
