De Smet’s post office opened in 1890, and 1 of its places is on the National Register
Most of De Smet was built recently: 0.0% of its homes predate 1940 and the median home dates from 1988. Its Register listing is the Coeur d'Alene Mission of the Sacred Heart.
How De Smet began
When was De Smet founded?
The De Smet post office opened in 1890, the earliest record of the town by name.
1 historic place in De Smet
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.
Questions about De Smet’s history
What year was De Smet founded?
The De Smet post office opened in 1890, the earliest record of the town by name (U.S. post office records).
What is on the National Register in De Smet?
One place: the Coeur d'Alene Mission of the Sacred Heart (listed 1975).
Memory lane
What the archives can’t tell you, neighbors can.
Where this page comes from
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 the National Register of Historic Places (1), 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.