Each edition grades its towns against each other only.
More historic than 22% of U.S. towns · #434 of 847 in California. What drives it
Most of El Rio was built recently: 4% of its homes predate 1940 and the median home dates from 1956. Below: maps from 1904 on and the census since 1950.
El Rio dates its founding to 1875 (Wikipedia’s history). The census first counted it in 1950.
El Rio was first named New Jerusalem by Simon Cohn in 1875.
The post office later changed its name to El Rio in 1895, which is the Spanish translation for “the river”.
More historic than 22% of U.S. towns, on its age, its old homes and the National Register.
On its age, its old homes and the National Register, El Rio is more historic than 22% of U.S. towns, #434 of 847 in California. Its age holds the grade up; its National Register listings pull it down.
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 El Rio’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.
Founding year: Wikipedia (other dates in Quick answers). 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 →
Read from the archive, the National Register and the record. The page puts what stands out first.
The first neighbors to add old photos shape how El Rio’s history is told.
Every edition of the U.S. Geological Survey’s map of El Rio. Tap a year, or press play to watch the town change.
U.S. Geological Survey historical topographic maps (public domain), via Esri’s collection of the scans. The red ring marks the center of El Rio.
El Rio had its own post office from 1895 to 1911. Two other post offices opened and closed inside today’s town.
US Post Offices dataset (Blevins & Helbock, CC0). Places and cemeteries from the USGS Geographic Names Information System (2021).
From Wikipedia’s history of El Rio.
Early inhabitants of the area were the Chumash, a Native American tribe who continue to inhabit the area. The Chumash region extends from Point Conception to Santa Monica and back into the foothills as far as the Coast Range. One of their largest settlements was at nearby Saticoy, because of the bubbling springs that were found there.
Text from Wikipedia, licensed CC BY-SA 4.0.
Woven from the archive, old maps, post office records, the National Register and the people born here.
On the mapFirst mapped by the U.S. Geological SurveyWeddings on Main Street, storms, parades, school pictures, the old store. If it’s in your family album, it belongs here.
Between 1,376 and 7,198 people in every census since 1950.
8 censuses, 1950–2020.
U.S. Census Bureau decennial counts, from the census table on El Rio’s Wikipedia page.
Nobody well known was born in El Rio itself, so here are the best known from just nearby.
Each neighbor’s History grade, on the same three inputs.
In 1875, according to Wikipedia’s history of the town. El Rio’s post office opened in 1882, and the census of 1950 counted 1,376 people here.
El Rio is more historic than 22% of U.S. towns, #434 of 847 in California. 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.
4% of El Rio’s homes were built before 1940 (Census estimate, ±3.6 points), against a typical 3.4% for a California town; the median home was built in 1956.
What the archives can’t tell you, neighbors can.
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.
