Founding year: the first Soap Lake post office (Blevins & Helbock, CC0).The full story ↓
History grade
What drives Soap Lake’s History grade
On its age, its old homes and the National Register, Soap Lake is more historic than 23% of U.S. towns. Its share of homes from before 1940 holds the grade up; its age pulls it down.
C−
HistoryA character grade: shown, never part of Soap Lake’s overall grade.
Few Washington towns list much on the Register (a typical Washington town has 0.1 per 10,000 residents, the U.S. 2.4), so Soap Lake’s 0.0 sits below most of its state (27% of Washington towns have fewer) while its 0 listings outnumber those of 23% of U.S. towns.
How sure. Graded on any two of the three inputs instead, the letter would range from D to C+. The pre-1940 share is a Census survey estimate (±9.9 points). The founding year is the first post office, not a stated founding date.
Founding year: the first post office (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 Soap Lake’s past
Read from the archive, the National Register and the record. The page puts what stands out first.
Growth in the area came to a halt during the Great Depression when drought hit Soap Lake. Because of the lack of water and money, the tourist trade dwindled. But, when Grand Coulee Dam was built, the irrigation canals brought new life into the area. Soap Lake has been internationally known during the past century for its uniquely mineral-rich (23) waters and mud. Many people believe the water and mud to be successful in treatment of a variety of ailments. From the early 1900s to the mid-1940s, there were a number of sanitariums located on Soap Lake.
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.
The Soap Lake post office opened in 1905, the earliest record of the town by name (U.S. post office records).
How does Soap Lake rank for history?
Soap Lake is more historic than 23% of U.S. towns. 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 Soap Lake?
17% of Soap Lake’s homes were built before 1940 (Census estimate, ±9.9 points), against a typical 4.3% for a Washington town; the median home was built in 1956.
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), the Library of Congress (1), Wikipedia, Wikidata and Wikipedia for famous people, U.S. Geological Survey historical maps, U.S. Census counts (via Wikipedia), 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.
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