Each edition grades its towns against each other only.
More historic than 82% of U.S. towns · #25 of 847 in California. What drives it
13 places in town are on the National Register, among them two historic districts with 4 buildings between them. Below: 15 old photos and papers, maps from 1896 on, and the census since 1960.
Altadena dates its founding to 1887 (Wikidata). The census first counted it in 1960.
More historic than 82% of U.S. towns, on its age, its old homes and the National Register.
On its age, its old homes and the National Register, Altadena is more historic than 82% of U.S. towns, #25 of 847 in California. Its share of homes from before 1940 holds the grade up; its age pulls 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 Altadena’s 4.1 sits above most of its state (86% of California towns have fewer) while its 17 historic buildings outnumber those of 79% of U.S. towns.
Founding year: Wikidata (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.
Every edition of the U.S. Geological Survey’s map of Altadena. 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 Altadena.
The country’s official list of buildings and places worth saving.
National Park Service, National Register of Historic Places. Photos from Wikimedia Commons, credited on each place’s page.
7 decades in the archive, from the 1880s to the 1960s. Scroll each row; tap a photo for its story.
1887178—Las Casitas views--All Aboard for Brown's Peak
1894LA Terminal RW
1897–1924Detroit Photographic Company (0099)
c. 1900Forest on Mount Lowe, near Altadena, California, ca.1…
c. 1900Sierra Madre Mountain forested slope, ca.1900 (CHS-96…
c. 1900Spring in the forest on Mount Lowe, Altatena, Califor…
1906The motorized Altadena float parading down the street…
1908Birdeye
1908BirdeyeFrom Wikipedia’s history of Altadena.
The name Altadena was coined by Byron O. Clark, who established Altadena Nursery in 1875. The name combines the Spanish alta, meaning "upper", with dena, a term he adapted from Pasadena. The area is adjacent to, but at a higher elevation than, Pasadena.
Text from Wikipedia, licensed CC BY-SA 4.0.
Passages that mention Altadena, cut from the printed page as they were published.
railway in Pasadena, organized the Pasadena Street Railway Company, and built the road; also built nearly all the street railroads in the city, as also the Alhambra and Altadena Street Railroad. He is now president of the company named, and is sole proprietor of the mills of the Pasadena Milling Company, which do a prosperous business. At present he has some large
Text read by machine from the scan; it may contain errors.
railway in Pasadena, organized the Pasadena Street Railway Company, and built the road; also built nearly all the street railroads in the city, as also the Alhambra and Altadena Street Railroad. He is now president of the company named, and is sole proprietor of the mills of the Pasadena Milling Company, which do a prosperous business. At present he has some large
Text read by machine from the scan; it may contain errors.Scans and text from the Internet Archive. Books published in 1930 or earlier, which are in the public domain.
Woven from the archive, old maps, post office records, the National Register and the people born here.
BuiltCrank House is builtIn the archive178—Las Casitas views--All Aboard for Brown's Peak
BuiltAndrew McNally House is builtBuiltMount Lowe Railway is builtIn the archiveLA Terminal RW
On the mapFirst mapped by the U.S. Geological SurveyIn the archiveForest on Mount Lowe, near Altadena, California, ca.1900 (CHS-962)
In the archivePergola at the F.S. Allen bungalow in Altadena, 1910 (CHS-5218)
In the archivePoppy field in Altadena, California, ca.1920 (CHS-1293)
Born hereMarni Nixon is born here
In the archiveSt. Elizabeth Church, Altadena 1935
Born hereSharon Stouder is born hereFire insurance maps drew every building, what it was made of and what it was used for, so insurers could price the risk of fire. Pick a sheet.
1908Sheet 1 of 2Sanborn Map Company, via the Library of Congress. Editions published in 1930 or earlier, which are in the public domain.
No then-and-now pairs yet. Take a photo from the same spot as an old one and they appear here side by side.
Find the spot, match the angle, and add your photo. It becomes the first then-and-now pair on Altadena’s page.
Retake this view · +15Between 40,568 and 42,846 people in every census since 1960.
7 censuses, 1960–2020.
U.S. Census Bureau decennial counts, from the census table on Altadena’s Wikipedia page.
Writers, athletes, leaders and more, ranked by how widely they’re known.
Altadena had its own post office from 1894 to 1920. Another post office, Mount Lowe, 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).
Most archives stop around 1920. The photos from after that are in family albums, not libraries.
Each neighbor’s History grade, on the same three inputs.
In 1887, according to Wikidata. Altadena’s post office opened in 1894, and the census of 1960 counted 40,568 people here.
Altadena is more historic than 82% of U.S. towns, #25 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.
13 listings: 9 buildings, among them the Pacific Electric Railway Company Substation No. 8 (listed 1977, the first), 2 historic districts, the Farnsworth, Gen. Charles S., County Park and the Zane Grey Estate, with 4 contributing buildings, and 2 sites. 17 historic buildings in all.
37% of Altadena’s homes were built before 1940 (Census estimate, ±3.7 points), against a typical 3.4% for a California town; the median home was built in 1946.
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 Wikimedia Commons (17), the Library of Congress (1), the National Register of Historic Places (13), Wikipedia, Wikidata and Wikipedia for famous people, U.S. Geological Survey historical maps, U.S. Census counts (via Wikipedia), the US Post Offices dataset (Blevins & Helbock), the USGS Geographic Names Information System, Sanborn fire insurance maps (Library of Congress) and old county and town histories (Internet Archive). Archive images are copied here with their credits and licenses, shown on each photo’s page. Refreshed monthly.
c. 1915
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