First settled in 1850, it was the original town in Eureka Township and an early gold mining center for Nevada County. As was popular at the time, the town was named Eureka, the state motto ("I have found it"), in honor of California's admission in September 1850, to the Union. Many other early Nevada County sites carried the Eureka name, including Eureka Hill, Eureka Mine, Eureka School District, Eureka Heights Residential District in Grass Valley, and Eureka House, an early tavern and inn built in 1850–1851.
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). How TownRatings grades history →
From Wikipedia, U.S. Geological Survey historical maps, 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.