On its age, its old homes and the National Register, Santa Rosa Valley is more historic than 10% of U.S. towns, #680 of 847 in California. Its National Register listings hold the grade up; its share of homes from before 1940 pulls it down.
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HistoryA character grade: shown, never part of Santa Rosa Valley’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 Santa Rosa Valley’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 (±1.5 points) is firm at this size.
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 Santa Rosa Valley’s past
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 Santa Rosa Valley. Tap a year, or press play to watch the town change.
1900Triunfo Pass 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 Santa Rosa Valley.
The story so far
Santa Rosa Valley, in brief
Wikipedia doesn’t have a history of Santa Rosa Valley yet. The photos, dates and memories neighbors add here are how it gets written.
Santa Rosa Valley is a rural unincorporated community, named after the eponymous valley in which it lies, located in Ventura County, California, United States. For statistical purposes, the United States Census Bureau has defined Santa Rosa Valley as a census-designated place (CDP). The census definition of the area may not precisely correspond to local understanding of the area with the same name. The 2020 United States census reported Santa Rosa Valley's population was 3,312. Santa Rosa Valley sits at an elevation of 433 feet (132 m). It lies within Ventura County north of Newbury Park, between Thousand Oaks and Camarillo. Norwegian Grade, which was constructed by the Norwegian Colony, co…
Its population held steady between the last two censuses: 3,334 in 2010, 3,312 in 2020.
Intro from Wikipedia. Population: U.S. Census Bureau.
By decade
No old photos in the archives yet
Weddings on Main Street, storms, parades, school pictures, the old store. If it’s in your family album, it belongs here.
Be the first to add onePhotograph a print flat, in daylight, no flash.
Santa Rosa Valley is more historic than 10% of U.S. towns, #680 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.
How old are the homes in Santa Rosa Valley?
1% of Santa Rosa Valley’s homes were built before 1940 (Census estimate, ±1.5 points), against a typical 3.4% for a California town; the median home was built in 1986.
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 U.S. Geological Survey historical maps. Archive images are copied here with their credits and licenses, shown on each photo’s page. Refreshed monthly.
