On its age, its old homes and the National Register, Hidden Valley is more historic than 7% of U.S. towns, #589 of 593 in Indiana. 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 Hidden Valley’s overall grade.
Indiana towns list more on the Register than most of the country (a typical Indiana town has 7.9 per 10,000 residents, the U.S. 2.4), so Hidden Valley’s 0.0 sits below most of its state (22% of Indiana 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 (±0.9 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 Hidden Valley’s past
Read from the archive, the National Register and the record. The page puts what stands out first.
The community and lake were built by land developer James Jacob Rupel, who was active in the Greater Dayton area and Indiana for over 50 years and the former owner of Centre City Building and the Carillon House in downtown Dayton. He was the developer of Hidden Valley Lake, several subdivisions near Rocky Fork State Park in Highland County, Ohio, the Valley Woods community in Greendale, Indiana, and the Country Squire Lakes community in North Vernon, Indiana.
Every edition of the U.S. Geological Survey’s map of Hidden Valley. Tap a year, or press play to watch the town change.
1928Lawrenceburg 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 Hidden Valley.
Stories next door
History across the town line
Each neighbor’s History grade, on the same three inputs.
Hidden Valley is more historic than 7% of U.S. towns, #589 of 593 in Indiana. 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 Hidden Valley?
0.6% of Hidden Valley’s homes were built before 1940 (Census estimate), against a typical 14% for an Indiana town; the median home was built in 1994.
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 and U.S. Geological Survey historical maps. Archive images are copied here with their credits and licenses, shown on each photo’s page. Refreshed monthly.
