Green River’s post office opened in 1853, and 5 of its places are on the National Register
More historic than 37% of U.S. towns · #19 of 28 in Wyoming. What drives it
Most of Green River was built recently: 4% of its homes predate 1940 and the median home dates from 1977. 5 places in town are on the National Register, among them the Expedition Island, a National Historic Landmark, and a historic district with 11 buildings. Below: 6 old photos and papers, maps from 1894 on, and the census since 1870.
Founding year: the first Green River post office (Blevins & Helbock, CC0). Wikidata: 1868.The full story ↓
History grade
What drives Green River’s History grade
On its age, its old homes and the National Register, Green River is more historic than 37% of U.S. towns, #19 of 28 in Wyoming. Its National Register listings hold the grade up; its share of homes from before 1940 pulls it down.
C+
HistoryA character grade: shown, never part of Green River’s overall grade.
Wyoming towns list more on the Register than most of the country (a typical Wyoming town has 25.1 per 10,000 residents, the U.S. 2.4), so Green River’s 12.1 sits near the middle of its state (49% of Wyoming towns have fewer) while its 14 historic buildings outnumber those of 78% of U.S. towns.
How sure. Graded on any two of the three inputs instead, the letter would range from C− to B−. The pre-1940 share (±2.3 points) is firm at this size. The founding year is the first post office, not a stated founding date; Wikidata’s 1868 falls in the same era, so the grade doesn’t depend on which one is used.
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 Green River’s past
Read from the archive, the National Register and the record. The page puts what stands out first.
National Park Service, National Register of Historic Places. Photos from Wikimedia Commons, credited on each place’s page.
Every building
Green River, building by building, 1894–1920
Fire insurance maps drew every building, what it was made of and what it was used for, so insurers could price the risk of fire. Pick a year, then a sheet.
The townsite of Green River, Dakota Territory was platted by the Union Pacific Railroad in 1867. Although the Territory of Wyoming was created on July 25, 1868, the Town of Green River was incorporated on August 21,1868 under the laws of the previous Territory of Dakota since the laws of the Wyoming Territory had yet to be written. The Town of Green River was re-incorporated on June 10, 1891 under the laws of the State of Wyoming to remove any ambiguity.
The Green River post office opened in 1853, the earliest record of the town by name (U.S. post office records). Wikidata gives 1868.
How does Green River rank for history?
Green River is more historic than 37% of U.S. towns, #19 of 28 in Wyoming. 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.
What is on the National Register in Green River?
5 listings: 3 buildings, 1 historic district, the Green River Downtown Historic District, with 11 contributing buildings, and 1 site. 14 historic buildings in all.
How old are the homes in Green River?
4% of Green River’s homes were built before 1940 (Census estimate, ±2.3 points), against a typical 12% for a Wyoming town; the median home was built in 1977.
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 (6), the National Register of Historic Places (5), 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), the USGS Geographic Names Information System and Sanborn fire insurance maps (Library of Congress). Archive images are copied here with their credits and licenses, shown on each photo’s page. Refreshed monthly.
★ Landmark
1858
1858
1871
1871
