More historic than 4% of U.S. towns · #812 of 847 in California. What drives it
Most of Discovery Bay was built recently: 1% of its homes predate 1940 and the median home dates from 1995. Below: 1 old photo or paper, maps from 1913 on, and the census since 1980.
On its age, its old homes and the National Register, Discovery Bay is more historic than 4% of U.S. towns, #812 of 847 in California. Its National Register listings hold the grade up; its age pulls it down.
D−
HistoryA character grade: shown, never part of Discovery Bay’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 Discovery Bay’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.
NoteThe founding year comes from Wikidata alone; no second source gives 1964.
How sure. Graded on any two of the three inputs instead, the letter would range from D− to D. The pre-1940 share (±0.8 points) is firm at this size.
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 →
What stands out about Discovery Bay’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 Discovery Bay. Tap a year, or press play to watch the town change.
1913Woodward sheet · 1:31,680
U.S. Geological Survey historical topographic maps (public domain), via Esri’s collection of the scans. The red ring marks the center of Discovery Bay.
Discovery Bay began as a planned community in 1964, and originally designated as "Riverside" and "River Lake." It was built on land known as the Byron Tract, which was previously used for growing barley and potatoes. In 1968, Jurgen Lunding led an effort to give the community its current name.
In July 2007, Discovery Bay received its own ZIP code: 94505. Formerly, it had shared 94514 with Byron. The ensuing celebration included a paddle boat raft-up that set a world record.
Nothing in the archives for these yearsWeddings on Main Street, storms, parades, school pictures, the old store. If it’s in your family album, it belongs here.
In 1964, according to Wikidata. the census of 1980 counted 1,326 people here.
How does Discovery Bay rank for history?
Discovery Bay is more historic than 4% of U.S. towns, #812 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 Discovery Bay?
1% of Discovery Bay’s homes were built before 1940 (Census estimate), against a typical 3.4% for a California town; the median home was built in 1995.
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 (5), Wikipedia, U.S. Geological Survey historical maps, U.S. Census counts (via Wikipedia) 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.
2025
2025
2012
2012
