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History · Ismay

Ismay’s post office opened in 1908, and 1 of its places is on the National Register

Its Register listing is the Ismay Jail. Below: maps from 1910 on and the census since 1920.

1908first post office

1on the National Register

0.0%homes built before 1940

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Quick answers

How Ismay began

When was Ismay founded?

1908

The Ismay post office opened in 1908, the earliest record of the town by name.

First census: 344 in 19202020 census: 17118 years

Founding year: the first Ismay post office (Blevins & Helbock, CC0).

What stands out about Ismay’s past

Read from the archive, the National Register and the record. The page puts what stands out first.

A history waiting to be writtenNo old photos of Ismay are in the public archives yet. The rest are in attics and albums.Mapped building by building3 fire insurance maps, 1910 to 1928, drew every building in Ismay.

★ What stands out · Help out

Start Ismay’s collection

The first neighbors to add old photos shape how Ismay’s history is told.

Decades since 1900 with photos

00s10s20s30s40s50s60s70s80s90s

0 of 10 decades. The empty ones are waiting for someone’s album.

Share a family photoSign in to add one+10

Every building

Ismay, building by building, 1910–1928

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.

1910Sheet 1 of 1

Edition

Sheets

BrickWoodStone

Sanborn Map Company, via the Library of Congress. Editions published in 1930 or earlier, which are in the public domain.

The story so far

Ismay, in brief

Wikipedia doesn’t have a history of Ismay yet. The photos, dates and memories neighbors add here are how it gets written.

Ismay is a town in Custer County, Montana, United States. The population was 17 at the 2020 census. The town is the least-populous incorporated municipality in the state of Montana. The town's name is an amalgamation of Isabella and May, the names of the daughters of Albert J. Earling, division superintendent (later president) of the Chicago, Milwaukee and St. Paul Railway. Other communities with related names include Earling, Iowa; Marmarth, North Dakota; and Alberton, Montana. As a publicity stunt coordinated by Kansas City radio station KYYS in 1993, the town unofficially took the name of Joe, Montana, after the NFL quarterback Joe Montana. The town's history and contemporary state (circ…

Its first post office opened in 1908. Between the 2010 and 2020 censuses its population fell from 19 to 17 (-11%).

Intro from Wikipedia. Population: U.S. Census Bureau.

By decade

Ismay, decade by decade

Today1 recent

2016Ismay Jail (2016) - Custer County, Montana

On the map

Ismay on the map, 1953 to 1981

Every edition of the U.S. Geological Survey’s map of Ismay. Tap a year, or press play to watch the town change.

1953Miles City sheet · 1:250,000

U.S. Geological Survey historical topographic maps (public domain), via Esri’s collection of the scans. The red ring marks the center of Ismay.

On the National Register

1 historic place in Ismay

The country’s official list of buildings and places worth saving.

place listed

National Historic Landmarks

none yet

historic buildings protected

each building in a district counts

first listed

1997

Ismay Jail

Buildings

Ismay JailBuilding

National Park Service, National Register of Historic Places. Photos from Wikimedia Commons, credited on each place’s page.

People over time

Ismay, census by census

Between 17 and 344 people in every census since 1920.

11 censuses, 1920–2020.

U.S. Census Bureau decennial counts, from the census table on Ismay’s Wikipedia page.

Places that used to be

Places now gone

Ismay’s post office has been open since 1908.

Gone or out of use

Burt Schoolschool

US Post Offices dataset (Blevins & Helbock, CC0). Places and cemeteries from the USGS Geographic Names Information System (2021).

Questions about Ismay’s history

What year was Ismay founded?

The Ismay post office opened in 1908, the earliest record of the town by name (U.S. post office records).

What is on the National Register in Ismay?

One place: the Ismay Jail (listed 1997).

Memory lane

What the archives can’t tell you, neighbors can.

Town Square →

Start a conversation

Sources

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 Wikimedia Commons (1), Wikidata (1), the National Register of Historic Places (1), 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.

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